Larry
SF

Hey, Larry. I'm in San Jose (I know it's not that close to you, but it might help) I need a portable antenna that will receive signals about 40 mi. away from me. Is it possible that there will be one that fits this or am I screwed? Thanks

Thanks for the reply, jtbell.

I got the Vikings game a few weekends ago on Ch33 at my in-laws, with a signal strength of 90% so, yes, it's definitely on the air. Their antenna is about 20' up, 5.77 miles from the transmitter. We're just over four times that distance.

TVFool indicates a signal power of -53.7dbm for them (though their antenna is actually situated behind a grove of 30-40 foot trees). Ours looks like it would be -80.3dbm with a 15ft height. Going to 30ft only gains us 1dbm.

I'm thinking no dice on FOX, unless I'm interpreting this incorrectly? :confused:

As arxaw noted, ch 33 is definitely do-able. I get stations down to at least -90dbm reliably with an AntennasDirect 91XG. You can see a couple of pics of my setup at the link in my signature.

Hey, Larry. I'm in San Jose (I know it's not that close to you, but it might help) I need a portable antenna that will receive signals about 40 mi. away from me. Is it possible that there will be one that fits this or am I screwed? Thanks
Heh, what do you consider portable ? Also post your TVFool image and the stations that you are most interested in.

You can build a foldable GH, that when folded, fits in your pocket. Its good for uhf for 40 - 50 miles away (about 7 to 11+ dbi bi-directional). If I do say so myself, its probably about the best performing uhf antenna that fits in a pocket, heh heh.
http://img29.imageshack.us/img29/4900/myfoldablegh.jpg

7 inch legs, 5.6 inch stubs, 3.5 inches between inside points. Locks in place using wing nuts. I made the above using old timey formica trim moulding which has a lip on it, so when locked in place, the 90 and 135 degrees angles are correct. Others have built it using notched aluminum flat bar.

When finished, it takes only a few minutes to assemble and disassemble. (I only loosen the wing nuts about 1/4 inch to fold up)

I'd love to see a sweep of that thing. :D

Heh, what do you consider portable ? Also post your TVFool image and the stations that you are most interested in.


Well... lol, That's not portable enough. Thanks though. I need it for work where it's small enough to carry in a bag and can be placed on the desk temporarily kind of antenna. Thanks for the help in advance.

I guess it would be channel 7 (KGO) and 11 (KNTV). But it's probably the one that's 40 mi. away that are the issue more than near me.

Like this?
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27ee8d361a47e8

A simple RabbitEars/Loop antenna should do the job for stations in the "green" zone:
http://i302.photobucket.com/albums/nn88/EscapeVelo/IMG_0095.jpg

Or just the UHF Loop (see jpg above) if you don't "need" the Hi-VHF stations....
Amplified would be better if you want to spend the extra cash & have an outlet...

A simple monopole "whip" came with my USB Stick Tuner, sort of like the following.
They only work with strong signals....but you might get lucky:
http://www.dealextreme.com/details.dx/sku.5174
http://www.radioshack.com/product/index.jsp?productId=2103159#tabsetBasic
http://www.radioshack.com/graphics/uc/rsk/Support/ProductManuals/2000006_PM_EN.pdf

There are numerous Indoor Antennas to chose from, including pictures, in EV's thread:
http://www.avsforum.com/avs-vb/showthread.php?t=1037779

If you want something somewhat more "collapsible", consider using bare AWG12
"house wire" that you shape into a 7.75-in diameter loop for UHF and another
21-in diameter loop for Hi-VHF (insulation on wire is okay). Perhaps you could
hang them from the ceiling??? Either swap them or use a UVSJ combiner.
And simply fold it up to fit into your bag:
http://photos.imageevent.com/holl_ands/loops/uhfcircular//UHF%20CIrcular%20Loop%20-%20AWG12%20-%20Compare%20Diameters.jpg
http://photos.imageevent.com/holl_ands/loops/vhfloop//Hi-VHF%20CIrcular%20Loop%20-%20Compare%20Element%20Sizes_1.jpg

I was entertaining this antenna although I'm not sure the actual size. I'm also not sure about it's performance because of mixed results in a search for it.

http://www.amazon.com/RCA-ANT1650-Digital-Amplified-Antenna/dp/B0027FGW3K/ref=sr_1_1?ie=UTF8&s=electronics&qid=1266173139&sr=8-1

I'll check that round up guide. Dunno why that didn't come up when I did a search on this forum. Thanks.


http://www.dealextreme.com/details.dx/sku.5174

This is pretty much what came with my usb tv tuner card and why I can't get the far stations.

I'd love to see a sweep of that thing.

4nec2 throws fits about it because of the wide bar, but in actual testing comparing it to other 10 dbi antennas I have, it follows this graph quite well IMO. (I also can get real channel 6 on it from 61 miles away, despite the very high negative gain. But thats because WPVI quadrupled their power, not the antenna)

http://img136.imageshack.us/img136/8350/foldingsbghrawgain.jpg

and can be placed on the desk temporarily kind of antenna.
The unfolded size is 25" wide by 30" high. I do have a desk stand made for it that I made from 1 telescoping/swiveling rabbit ear on a block. This props it up on a desk. I also made a wall hanger from 2 alligator clips and nylon string. The whole antenna, desk stand and wall hanger fit into a 1 1/2" X 2 1/2" X 9" long box when folded, heh. Coax and balun are carried along separately.

Hey, Larry. I'm in San Jose (I know it's not that close to you, but it might help) I need a portable antenna that will receive signals about 40 mi. away from me. Is it possible that there will be one that fits this or am I screwed? Thanks

I think you've got some really good suggestions from the group here, Vip... but 40 miles is a pretty long distance to receive stations with a small antenna. You really need something up on the roof to get reliable reception and to avoid constantly having to tweak and adjust the antenna. But since you need something small and portable, the suggestions shown are probably your best bets. No guarantees on how well they'll work though. Good luck!

Larry
SF

Hi, all. I really appreciate all the great information contained in these forums. There's a lot of care and expertise that has gone into compiling such a wealth of knowledge, and it shows.

I do have a specific question I'd like some guidance on. I recently upgraded to a HD TV, and my cable company wants a major upgrade to service in order to provide HD programming. ("fiber" provider, blech!) Anyway, I thought this might be a good opportunity to give OTA a shot. I generated a TVfool analysis (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27eed08de0a354), but I can't make much sense of it. It does seem that some of the numbers are a bit conservative based on what I've seen some of my neighbors achieve, but it could be due to the wooded area in which I live. I'm about 40 miles from the towers in Savannah, Ga.

I'd like to try an indoor antenna, obviously, and I have my eye on the DIY antenna described in another thread, but if that's not going to be a practical solution for me, then why waste the time? Could anyone make a recommendation for my situation?

Thanks.

The colors on your report, correspond to the range of the antenna. An antenna that is designed for the "Green" area, will have a tough time acquiring stations that are in the "Red" area. Of course, an antenna designed for the "Red" area will be able to acquire the stations in the "Green" and "Yellow" areas very easily. Beyond the "Red" area, you'll need a pre-amplifier and some height.

Looks like you can get all the Networks except for MyNetwork and iON. You should be able to receive stations down to -23dB NM, if you have the right setup. I don't believe you'll be happy with an indoor antenna.

The report shows you that most of your stations are 2edge reception (meaning there are obstructions to a RF Line-of-Sight to the transmitting antennas). It shows the distance to the transmitting towers, the "TRUE" heading, and the "Magnetic" (compass) heading.

Since you have stations in all three bands of the television OTA spectrum, you'll need a VHF/UHF combo antenna. You also have stations in multiple directions, which will require a rotor. Don't count on reliable (if any) reception of the "Tropo" stations. Those are stations, where you are getting reflected signals from the Ionosphere.

The colors on your report, correspond to the range of the antenna. An antenna that is designed for the "Green" area, will have a tough time acquiring stations that are in the "Red" area. Of course, an antenna designed for the "Red" area will be able to acquire the stations in the "Green" and "Yellow" areas very easily. Beyond the "Red" area, you'll need a pre-amplifier and some height.

Looks like you can get all the Networks except for MyNetwork and iON. You should be able to receive stations down to -23dB NM, if you have the right setup. I don't believe you'll be happy with an indoor antenna.

The report shows you that most of your stations are 2edge reception (meaning there are obstructions to a RF Line-of-Sight to the transmitting antennas). It shows the distance to the transmitting towers, the "TRUE" heading, and the "Magnetic" (compass) heading.

Since you have stations in all three bands of the television OTA spectrum, you'll need a VHF/UHF combo antenna. You also have stations in multiple directions, which will require a rotor. Don't count on reliable (if any) reception of the "Tropo" stations. Those are stations, where you are getting reflected signals from the Ionosphere.
So a roof mount is likely my only workable option? Honestly, most of the stations I care about will be SE of here. The rest are going to be mostly local networks from other, non-local markets. If I'm interested mainly in reception of the closest channels, the ones to the SE, what would you suggest?

I suppose it's also somewhat worth noting that I'd planned to use the existing dish mount which is oh so conveniently located on the North corner of the house. Oh, well.

I assume everyone is talking about a rotator. I don't know what a rotor is (except in my garbage disposal)

Pascal Marcoux presented a paper at the IEEE Broadcast Technology Symposium in Oct 2009,
"Revisiting the Field Strength Requirements for DTV in the Canadian Context", but apparently
it hasn't yet been published, other than the fol. VU-graph presentation:
http://www.ccbe.ca/Downloads/CCBE2009-RevisitingDTVminFS.pdf
There is probably a lot of "specsmanship" going on here. For example, HBU-22
"specs" simply say 4.1 dBd Hi-VHF and 7.3 (not 7.2) dBd UHF Gain without saying
which channel nor whether it was guaranteed minimum (fat chance), some sort of
"average", "typical" (whatever that is supposed to mean) or the max Gain found
somewhere in the band (very likely).....YMMV....
And since Marcoux didn't explain what HE was measuring, perhaps it was the
WORST Gain found somewhere in the band.....maybe, maybe not....YMMV....

Marcoux's presentation was briefly mentioned in Doug Lung's column in TV TECHNOLOGY magazine:
http://www.tvtechnology.com/article/90786

It includes test results on several antennas: an (unidentified) 4-Bay Bowtie w Reflector,
Antennacraft HBU-22 Hi-VHF/UHF Yagi, Terk HDTVi UHF LPDA + VHF RabbitEars and
one of the (unidentified) RCA Square Panels (such as ANT1650, et. al.).....which
should NOT be confused with the ANT2000 Smart Antenna.....

WOW, didn't know the Terk HDTVi was such a terrible Hi-VHF and UHF antenna!@!#!
And (as expected), fergit about using RCA Square Panel Omni antennas....

These are probably the worst examples to illustrate huge discrepancies between
manufacturer "specs" (such as they are) and actual performance.....YMMV....

I assume everyone is talking about a rotator.
That's correct.

Since you're only interested in the stations to the S.E., point your antenna at 137° (Magnetic). Your PBS station is VHF-High and close enough to not worry about. The furthest station is just under 41 miles, but as you posted earlier, there are "Woods" to worry about and you're dealing with 2-edge reception.

You could probably get by fairly well with one of the new VHF-High/UHF combo antennas.

JSTARLING,
When you entred your info for the TVfool report, at the very bottom there is a spot to put in hieght.
Try entring 25, 30 feet, what ever hieght your antenna will be mounted at.
This may give you a better picture of what you are looking at.
But I think you are looking at something large.

JSTARLING,
When you entred your info for the TVfool report, at the very bottom there is a spot to put in hieght.
Try entring 25, 30 feet, what ever hieght your antenna will be mounted at.
This may give you a better picture of what you are looking at.
But I think you are looking at something large.
That's what I'm figuring. Is there anywhere on TVfool that might give an actual recommendation on an antenna? You're talking to an OTA noob here.

I don't want to make a suggestion on an actual antenna as I'm no expert, others will chime in.
Until then here's a LINK (http://www.hdtvantennalabs.com/hdtv-antenna-zones.php) to a site that breaks it down and offers suggestions on specific antennas.
You are looking for a red code, medium directional antenna.
Click on the medium directional link under code red of that site for antenna recomendations.
There are reviews also.
You will need a high VHF(7-13) and UHF(14-69) antenna but, a full coverage VHF/uhf antenna will work, it will just be bigger.
It could be a combination antenna with both together in one or two seperate antennas joined at a UVSJ combiner.

The color codes used on that site are the ones that antenna manufacturers use for classifying their antennas according to type. TVFool uses a different set of color codes.

Generally speaking, the only stations you should expect to have a chance of getting with a small indoor (in-room) antenna are the ones that TVFool has marked as green.

For the yellow range, you can probably use a medium or large "outdoor" antenna in your attic, provided your roof is typical wood and shingle construction, not metal or tile. The antenna has to be somewhat larger than if you mounted it outdoors, to overcome the signal loss from going through the roof.

I don't have any direct experience with that kind of setup myself, so others will have to make specific recommendations. You have a couple of VHF stations (9 and 11) so you need an antenna that can receive those. You should avoid antennas that include the "low VHF" channels 2-6 because they're much larger than antennas that are designed for only "high VHF" (7-13) plus UHF.

If you do a search in this forum for the word "attic" you'll probably turn up some recommendations. Check their TVFool charts to make sure the signal strengths for their stations are similar to yours.

Thanks for the replies and the guidance. Hound, I'm looking at the link you posted, and it's providing some great ideas. I'm actually looking at the blue and red area antennae, and the TV sits more toward the other end of the house, so an amplifier is probably in order, given the distance to the set and the distance from the signal origination.

I do have my eye on something like the Terk HDTVo or Channel Master 2016 (or ANT751) for compact installation with a more discrete eve placement, but will something like that give me proper performance, or do I need to go with a full-on 50-element rooftop mount? Either way, I'm mounting this antenna outside. For me, it's less trouble than trying to feed a line down the wall, since my cable outlets are already in place and easily accessible from the crawl space.

"Revisiting the Field Strength Requirements for DTV in the Canadian Context"
Interesting presentation. As a casual observer of the DTV circus it never ceases to amaze me that many years into a process that profoundly changed broadcast and cost billions we are still using modeling assumptions that are so grossly inaccurate. I realize modeling is part art part science but it is not as if this had not been pointed out years ago.

I have purely selfish motivation in this. As a rural OTA viewer in hilly and wooded Southern NH I would dearly love a few more DB of signal strength.

Thanks for the replies and the guidance. Hound, I'm looking at the link you posted, and it's providing some great ideas. I'm actually looking at the blue and red area antennae, and the TV sits more toward the other end of the house, so an amplifier is probably in order, given the distance to the set and the distance from the signal origination.

I do have my eye on something like the Terk HDTVo or Channel Master 2016 (or ANT751) for compact installation with a more discrete eve placement, but will something like that give me proper performance, or do I need to go with a full-on 50-element rooftop mount? Either way, I'm mounting this antenna outside. For me, it's less trouble than trying to feed a line down the wall, since my cable outlets are already in place and easily accessible from the crawl space.

Another compact antenna to consider would be the Channel Master 4228HD, it is long range instead of mid range like the 2016. The 2016 is rated 35 miles high-vhf/uhf and the 4228HD is rated 45 miles high-vhf/60 miles uhf.

I assume everyone is talking about a rotator.

I see rotators recommended a lot, and they're good at what they do. My experience, however, is that if I've set the DVR to catch something while I'm away, the rotator is left in the wrong position and all I get is snow. A rotator also complicates things a lot for guests who are trying to watch TV. Therefore I use a combination of Join-Tenna plus combiner so that the antenna doesn't actually have to get rotated for any signal I have.

(Even so, I'm glad I have the rotator. Helps with diagnostics; and, because of it there was never a time when I had to get somebody on the roof, observe the signal and call out "a little to the right!" etc.)

(For that matter, I'm even glad I have an attic antenna. I ended up having to go to a rooftop antenna for best reception, but the attic antenna gets a nice signal from one station 90 degrees away from the others. It's a working part of the system even now.)

Another compact antenna to consider would be the Channel Master 4228HD, it is long range instead of mid range like the 2016. The 2016 is rated 35 miles high-vhf/uhf and the 4228HD is rated 45 miles high-vhf/60 miles uhf.
Best I can tell the 8-bay bowtie style is UHF only, right? I wouldn't even worry about it, but channel 9 is PBS, and if we can't get Elmo piped into our house in all his high def glory, it ain't gonna be pretty. :p

Best I can tell the 8-bay bowtie style is UHF only, right? I wouldn't even worry about it, but channel 9 is PBS, and if we can't get Elmo piped into our house in all his high def glory, it ain't gonna be pretty. :p

The cm-4228HD has a decent VHF side. It will reach out about 45 miles depending on the signal strength from the transmitter and your line of sight. It sounds a bit unfortunate for you as you will most likely be watching Elmo and friends. If you don't want to get Elmo you can use a cm-4221HD. This is a good UHF antenna, it does somtimes pick up VHF but it is not reliable for VHF. The specs on the UHF side of the cm-4221HD are almost the same as the cm-4228HD.

Hi everyone, I'm new to antennas but I found AntennaWeb.org and it's showing me being 49.9 miles from ABC/CBS/NBC. Is there an antenna out there that doesn't cost a lot that will work that far away and pick up the stations in HD?
I wouldn't be opposed to trying to build one myself but have no idea where to start :)
thanks for any advice!

edit - it says:
cbs - uhf
abc - vhf
nbc - vhf

Hi yourself. :)

If you want specific advice, people here prefer tvfool.com instead of antennaweb.org because it gives more detailed information about your signal strengths. Go there, enter your address or latitude/longitude, get their table of results and post a link to it here.

However, generally speaking, unless you have major hills in the way, or your're deep in a valley, or your stations are low-powered, reception at 50 miles is usually no problem with a decent antenna on the roof. A suitable antenna would probably cost $40-$80 depending on the manufacturer, plus the cost of mounting hardware and possibly installation if you don't feel up to climbing on your roof to do it.

An antenna in the attic might also work if your roof is ordinary wood and shingle construction, and would be easier (and safer!) to install yourself, but I think 50 miles might be pushing things. An antenna in the attic has to be bigger than one on the roof because the roof attenuates signals.

Hi yourself. :)

If you want specific advice, people here prefer tvfool.com instead of antennaweb.org because it gives more detailed information about your signal strengths. Go there, enter your address or latitude/longitude, get their table of results and post a link to it here.

However, generally speaking, unless you have major hills in the way, or your're deep in a valley, or your stations are low-powered, reception at 50 miles is usually no problem with a decent antenna on the roof. A suitable antenna would probably cost $40-$80 depending on the manufacturer, plus the cost of mounting hardware and possibly installation if you don't feel up to climbing on your roof to do it.

An antenna in the attic might also work if your roof is ordinary wood and shingle construction, and would be easier (and safer!) to install yourself, but I think 50 miles might be pushing things. An antenna in the attic has to be bigger than one on the roof because the roof attenuates signals.

Thanks, here's my link from tvfool.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27eec6112e61ee
What do you think might be a good option for me? I'm in an apartment but it has a balcony on the 2nd floor, nothing on top of my unit and nothing immediately blocking my line of site. I was planning on putting it on a pole on a tripod on the balcony.

Best I can tell the 8-bay bowtie style is UHF only, right? I wouldn't even worry about it, but channel 9 is PBS, and if we can't get Elmo piped into our house in all his high def glory, it ain't gonna be pretty. :p
Without revisiting your TVFool report, I believe PBS 9 is your strongest station and is VHF 9 LOS. You should be able to get that station fairly well, even with all the trees and being off-axis from your other stations. :)

Having a second floor balcony (facing towards channel 7), will require a VHF-High/UHF antenna setup. You have a few Line-of-Sight (LOS) stations and a lot of 1edge, but it appears you may have good signal strength. You didn't indicate a height on your report. Can you see if it makes any difference to your report by redoing the report with how high of the ground (AGL) that it would be mounted.

Some people use a bucket of cement to anchor their antenna pole in.

Thanks for the replies and the guidance. Hound, I'm looking at the link you posted, and it's providing some great ideas. I'm actually looking at the blue and red area antennae, and the TV sits more toward the other end of the house, so an amplifier is probably in order, given the distance to the set and the distance from the signal origination.

I do have my eye on something like the Terk HDTVo or Channel Master 2016 (or ANT751) for compact installation with a more discrete eve placement, but will something like that give me proper performance, or do I need to go with a full-on 50-element rooftop mount? Either way, I'm mounting this antenna outside. For me, it's less trouble than trying to feed a line down the wall, since my cable outlets are already in place and easily accessible from the crawl space.
Wanted to follow up on this post with some thoughts I've had following a few days of research and reading. It seems to me that if I'm going to be mounting an antenna on the roof, it's the same amount of effort whether I mount a discrete antenna that may work or if I mount a long-range Hi-VHF/UHF on the chimney that I know will work.

So, along that vein, I'm now looking in the red/blue range at a few options that I'd like some input on. I'm specifically looking at the Winegard HD7015 in the red zone and the CM3020 (or 3018?) in the blue. Would these be viable options for me, if mounted to a chimney above the roof peak? Is the CM3020 really preferable to the HD7015, given the price?

TVFool (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27eed08de0a354) for reference.

I use a 15 year old CM3020 (at 70+ miles, on top of a 55' tower) to recieve 2-edge reception. It has a high-gain channel master pre-amp (0265DSB) that is very similar to the CM7777. I also have a Channel Master 3414 DA to feed all the sets and VCR's.

I know of another user in Winchester, VA that uses a CM3020 also.

I receive stations from Altoona, Baltimore, D.C., York/Red Lion, and most of the LOS stations up and down the Valley I live in. I have lots of multi-path, military, and FM issues too.

The CM3020 is a full range antenna and will be very large, but if you have the room, it could be an option. There is some information (that I can't link to currently) about antenna performance comparisons with the CM3020.

Thanks, here's my link from tvfool.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27eec6112e61ee
What do you think might be a good option for me? I'm in an apartment but it has a balcony on the 2nd floor, nothing on top of my unit and nothing immediately blocking my line of site. I was planning on putting it on a pole on a tripod on the balcony.
Given the constraint re your balcony, the RCA ANT751 (aka EZHD) would
be a good choice for a small, medium performance Hi-VHF/UHF antenna:
http://www.rcaaccessories.com/rcaaccessories/RcaaccessoriesProductDetail.do?ACTION_TYPE_ID=ACTION_TYPE_PR ODUCT_DETAIL&ACTION_CATEGORY_IDSTR_CATEGORY_OUTDOOR_ANTENNAS&ACTION_PRODUCT_ID=ANT751
ANT751 was derived from the W-G HD7000R, except the 100-in long
elements were resized to 28-in, since Ch2-6 is not needed in most areas.
Only 30-inches long (plus J-Mount), Hi-VHF and UHF performance should
be about the same:
http://www.winegarddirect.com/pdf/HD7000R.pdf

CM4228HD 8-Bay antenna would have even higher UHF gain, and is only
somewhat less effective for the Hi-VHF channels. There is even a simple
mod to improve performance:
http://www.hdtvprimer.com/ANTENNAS/TemporaryPage.html

Or separate UHF and Hi-VHF antennas, such as A-D C5 for Hi-VHF and
a 4-Bay for UHF, combined with a UVSJ VHF/UHF Combiner.

A DIY alternative would be to build an oversized Super-4-Bay Antenna, without
a reflector to optimize Hi-VHF reception:
http://imageevent.com/holl_ands/multibay/4bay/super
http://www.frontiernet.net/~mclapp/Antennas/diagrams.html

If those are too big, alternative choices will have significantly lower gain on both
UHF and Hi-VHF, such as the Winegard HD1080....which may or may NOT work....

Having a second floor balcony (facing towards channel 7), will require a VHF-High/UHF antenna setup. You have a few Line-of-Sight (LOS) stations and a lot of 1edge, but it appears you may have good signal strength. You didn't indicate a height on your report. Can you see if it makes any difference to your report by redoing the report with how high of the ground (AGL) that it would be mounted.

Some people use a bucket of cement to anchor their antenna pole in.

Right now I'm planning on about 17 feet up, which is this:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27eeaee7fb8353

I think I could go to 21 though if that would help things, which is this:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27ee67298a04ef

no idea how to interpret that data so thanks for any help!

edit - also, is there a shop that is generally thought to be the cheapest to purchase from?

no idea how to interpret that data so thanks for any help!

Just compare the before and after NM figures. What a difference KRCB-DT channel 23 PBS (22.1) makes with 4 ft more in height. From -7.0 NM to 12.7 NM. Thats an incredibly huge difference !

Does anyone have any experience with a TB-105 alignment bearing with a Channel Master 9521A rotator? I am having trouble getting them to line up correctly with a 1 1/4" mast or a 2" mast. Any ideas of what could be going wrong. The mast seems to be 1/4" to 1/8" to close to the mast side of the bearing.

Thanks guys. Is there a shop where you recommend purchasing from? I was looking at the links above for building one and it looks a bit over my head with all the graphs etc.

I entered tb-105 in google search box at top of page. Here are two of many that came up:

http://www.avsforum.com/avs-vb/showpost.php?p=7971691&postcount=319
http://www.avsforum.com/avs-vb/showthread.php?t=546066&page=44 posts 1314 & 1315

I entered tb-105 in google search box at top of page. Here are two of many that came up:

http://www.avsforum.com/avs-vb/showpost.php?p=7971691&postcount=319
http://www.avsforum.com/avs-vb/showthread.php?t=546066&page=44 posts 1314 & 1315

That might explain why my CM rotator burnt up after a month or so after installing the TB105 and having 6' of mast above the bearing.

I just used the strong arm rotator and a pipe wrench from the base of the mast I built from Home Depot..

Just moved to a new place, so I'll have to wait for the ground to thaw before putting up the new CM1630 mast. I'll test fit the new rotator and old TB105 and make sure there is no binding this time :-). No beer on this install :-) might help with alignments.

~ryan

The cm-4228HD has a decent VHF side. It will reach out about 45 miles depending on the signal strength from the transmitter and your line of sight. It sounds a bit unfortunate for you as you will most likely be watching Elmo and friends. If you don't want to get Elmo you can use a cm-4221HD. This is a good UHF antenna, it does somtimes pick up VHF but it is not reliable for VHF. The specs on the UHF side of the cm-4221HD are almost the same as the cm-4228HD.
I'm currently revisiting this idea, based on additional information confirmed here (http://www.avsforum.com/avs-vb/showthread.php?t=1227911). It seems that if I get myself an 8-bay (deep range), I could get by with an attic mount, since the elevation brings most of my channels into yellow-zone range. It also means it could be mounted directly above the tv, probably eliminating the need for an amplifier.

Ok, I know I'm missing something. Anybody care to chime in? :)

Click on the picture link inside of this post to see how I am using a TB-105 and 9521A together. I'm not sure about the diameter of the mast, but I probably got it at Radio Shack.

http://www.avsforum.com/avs-vb/showthread.php?p=14275194&highlight=#post14275194

It's been up about 5 years and so far no problems.

Thanks guys. With the abundance of knowledge I have recieved here I think I got figured out. I will try it this weekend. Thanks all.

Thanks guys. Is there a shop where you recommend purchasing from? I was looking at the links above for building one and it looks a bit over my head with all the graphs etc.

I bought one recently online from Solid Signal and was happy with the price and how quickly it arrived.

A couple comments and questions I have about your installation:

1) Do other people have antennas on their balconies where you live? It seems to me that it might be an issue with the property owners. Hate to see you invest time and money and have them tell you to take it down.

2) You will also need a length of RG-6 cable, a mast, and a matching transformer in addition to the antenna. How will you route the cable into the apartment? The owners may get upset if you drill holes through the wall. You really should install a ground block as well since the antenna amounts to a bit of a lightning rod. A ground wire needs to go from the block to an earth ground. This too might be a problem to accomplish given your situation.

3) Do you have a metal railing? If so, it might interfere with your reception. I'd suggest mounting the antenna at least 2-3 feet above the railing.

4) Lastly, you may want to buy an indoor antenna from Radio Shack and at least give it a try. If it doesn't work for you, I've found they are very good about taking things back as long as you save all of the packing, etc. Although an outdoor antenna is certainly preferable, you live in a relatively strong signal area and might get away with an indoor one. It would be a lot simpler solution if it worked.

My two cents. Good luck with your setup.

Here are pictures of my homemade Dry Bearing setup: http://www.avsforum.com/avs-vb/showthread.php?p=15946674#post15946674

Detail information discussion starts on this page:
http://www.avsforum.com/avs-vb/showthread.php?t=381623&page=289

Fry's Electronics is in your area: www.frys.com

Don't forget to calculate shipping costs before you compare:
www.solidsignal.com
www.summitsource.com
www.starkelectronic.com
www.warrenelectronics.com
www.beachaudio.com
www.antonline.com
www.newegg.com
www.amazon.com

The ever popular Froogle and Pricegrabber search engines compare
prices with shipping cost and taxes included (be sure to double check):
www.google.com/products/
www.pricegrabber.com

PS: Although some networks are strong; FOX, CW and MyN are fairly weak
and will need a lot more than a simple indoor RabbitEars/Loop.
BTW: I think the big change in KRCB station (your 4th weakest PBS) is
some sort of artifact in the TVFool simulation program, rather than reality.

"NM" (Noise Margin) generally tells you how much antenna gain you
"need" for minimally useful service....but you also need to subtract out
other losses, such as indoor loss (10-20 dB). And any remaining positive
margin is desirable for long term reliability....

Pascal Marcoux presented a paper at the IEEE Broadcast Technology Symposium in Oct 2009,
"Revisiting the Field Strength Requirements for DTV in the Canadian Context", but
apparently it hasn't yet been published, other than the fol. VU-graph presentation:
http://www.ccbe.ca/Downloads/CCBE2009-RevisitingDTVminFS.pdf
There is probably a lot of "specsmanship" going on here. For example, HBU-22
"specs" simply say 4.1 dBd Hi-VHF and 7.3 (not 7.2) dBd UHF Gain without saying
which channel nor whether it was guaranteed minimum (fat chance), some sort of
"average", "typical" (whatever that is supposed to mean) or the max Gain found
somewhere in the band (very likely).....YMMV....
And since Marcoux didn't explain what HE was measuring, perhaps it was the
WORST Gain found somewhere in the band.....maybe, maybe not....YMMV....

Marcoux's presentation was briefly mentioned in Doug Lung's column in TV TECHNOLOGY mag:
http://www.tvtechnology.com/article/90786

It includes test results on several antennas: an (unidentified) 4-Bay Bowtie w Reflector,
Antennacraft HBU-22 Hi-VHF/UHF Yagi, Terk HDTVi UHF LPDA + VHF RabbitEars and
one of the (unidentified) RCA Square Panels (such as ANT1650, et. al.).....which
should NOT be confused with the ANT2000 Smart Antenna.....

WOW, didn't know the Terk HDTVi was such a terrible Hi-VHF and UHF antenna!@!#!
And (as expected), fergit about using RCA Square Panel Omni antennas....

These are probably the worst examples to illustrate huge discrepancies between
manufacturer "specs" (such as they are) and actual performance.....YMMV....
Links to some of the references cited in the Marcoux Presentation can be found here:
http://www.digitalhome.ca/forum/showthread.php?p=1062381

Links include papers by Dr. Bendov et. al. re parameters "missing" from the ILLR
propagation prediction program, esp. the Effect of VSWR on EVM (Error Vector Magnitude).

Also includes links to info re Height Gain and Indoor Propagation Loss.

Thanks for the replies and the guidance. Hound, I'm looking at the link you posted, and it's providing some great ideas. I'm actually looking at the blue and red area antennae, and the TV sits more toward the other end of the house, so an amplifier is probably in order, given the distance to the set and the distance from the signal origination.

I do have my eye on something like the Terk HDTVo or Channel Master 2016 (or ANT751) for compact installation with a more discrete eve placement, but will something like that give me proper performance, or do I need to go with a full-on 50-element rooftop mount? Either way, I'm mounting this antenna outside. For me, it's less trouble than trying to feed a line down the wall, since my cable outlets are already in place and easily accessible from the crawl space.

I installed the CM 2016 last weekend just the way you are thinking, on the side of the chimney just above the roof pitch. I previously had a Radio Shack U-75. Since the chimney is toward the back of the home, this installation hides the antenna from the street view while still being over the roof pitch. I am using the CM-7777 amp with RG-6 cable.

I live between 2 markets, Norfolk (30 miles from towers) and Richmond (55 miles from towers) and my goal was to receive programming from both markets. The U-75 was pointed toward Richmond and worked very well pulling in the Richmond UHF stations, but the Norfolk UHF stations coming in on the back side broke up constantly due to multi-path issues. Also VHF from Richmond was non existent and but was acceptable from Norfolk.

I purchases the CM 2016 with the hope it would pull in the VHF NBC station in Richmond, but it did not. What I did find was the UHF reception from the 55 mile away stations was just as good as the U-75. The CM2016 antenna did not have the multi-path issues from the closer stations. There was one Norfolk class-A station that was viewable on the U-75 but not the CM2016, but that station was just a translator for one of the full power stations that I could already receive well.

What I believe is the CM2016 UHF elements are doing a better job rejecting the close Norfolk signals which are now being received by the VHF elements. Instead of 90-100% signal for the Norfolk stations on the backside of the U-75 I now have 85-90% but without the multi-path interference I had before.

For my particular installation the antenna worked well and performed better than the 35 mile range advertised.

Links to some of the references cited in the Marcoux Presentation can be found here:
http://www.digitalhome.ca/forum/showthread.php?p=1062381

Links include papers by Dr. Bendov et. al. re parameters "missing" from the ILLR
propagation prediction program, esp. the Effect of VSWR on EVM (Error Vector Magnitude).

Also includes links to info re Height Gain and Indoor Propagation Loss.
I find the following sentences (from the TVTechnology link) very disturbing:

The finding that consumer antennas have gain 2.9 dB below specification (on average) should come as no surprise. "Low noise amplifiers (LNAs)" may not help as measurements showed only 2 out of 11 worked as specified.

and

Additional signal strength is needed to cover more man-made noise than expected….

And of course, the last sentence of the next to last paragraph says it all.
Now that TV broadcasting has transitioned to digital, signal saturation may become much more important than coverage contours.

I live between 2 markets, Norfolk (30 miles from towers) and Richmond (55 miles from towers) and my goal was to receive programming from both markets.

Try the Winegard HD 1080. It's F/B ratio and pattern seems ideal for your location.

Try the Winegard HD 1080. It's F/B ratio and pattern seems ideal for your location.
That makes no sense at all:
http://www.winegarddirect.com/pdf/hd-1080-spec.pdf

jccsup:
I looked at some of your old posts, but I didn't see a www.TVFool.com report.
Could you provide a link to your results?

From what I've seen using just your zipcode (post office) location,
you need a moderate gain Hi-VHF/UHF antenna if you want to receive
Richmond. HD-1080 would be inadequate, as was the CM2016.

You'll need an antenna with higher gain than those on the Hi-VHF channels.
What you need is a larger Combo Hi-VHF/UHF antenna (e.g. U-75) and either
a rotator, or a two-antenna configuration with the CM2016 aimed at Norfolk.
Combine unamplified CM2016 onto the coax, AFTER the Preamp connected
to the new antenna (use a DC PASS Satellite RF Splitter/Combiner).
If this causes multipath problems, you may have to run separate coax runs
and use an RF A/B Switch.

Does anyone have any experience with a TB-105 alignment bearing with a Channel Master 9521A rotator?The center point of rotation of the TB-105 does not match the center point of rotation of the CM-9521. The TB-105 center point of rotation is further away from the mast than the CM-9521. It may be possible to put a spacer between the mast and the CM-9521 to bring them into alignment.

I still haven’t gotten around to:
For a bearing to work correctly its center point of rotation must match that of the rotor. One of these days I am going measure the mount dimension and the mount-to-bearing dimension on the rotor, draw it up in CAD and take the bearing to a metal milling shop and have them cut the bearing to match the CM rotor.

That makes no sense at all:
http://www.winegarddirect.com/pdf/hd-1080-spec.pdf
I think hes trying to say the vhf max gain is flipped in direction to the uhf max gain. Not good for most, but beneficial to some. I have plenty of failed GH with NAROD (and a CM2016 clone) models that do the same thing. It actually seems much easier to get the gain in the opposite direction than the same direction, heh.

That makes no sense at all:
http://www.winegarddirect.com/pdf/hd-1080-spec.pdf


Actually, it does.

I ran a tvfool report on his location as given under the user name. The HD1080 has UHF side lobes that happen to fall on the Norfolk stations while the antenna aimed is aimed at Richmond.

This is better than the 2016 because the F/B ratio of the 2016 on UHF is too high.

I havent seen the pattern for the CM2016, but based on my CM2016 clone modeling (and oddly CM specs state multi-directional for vhf-hi), it too may have higher vhf-hi gain in the opposite direction. But the HD 1080 has two, as opposed to one, vhf-hi radiators (the longer reflectors), so it probably has the higher reverse vhf-hi gain.

HD-1080 UHF sidelobes appear to be very low gain...might not be enough
for Norfolk reception AND the main lobe will amplify multipath interference.
The above spec sheet doesn't have enough resolution to see the Gain scale.
Attached is a readable excerpt I extracted on an earlier date.

And as mentioned above, Hi-VHF gain towards Richmond is very low, with
the max VHF gain poking out the BACK of this ill-designed "antenna"
being only in the range of -4 to -5 dBi (worse than RabbitEars)....leaving
much less than this directed towards Richmond....again opening the
door to multipath....although not as bad as the UHF situation...

Of course, actual performance may not match the spec sheet...might be worse...

PS: In the two antenna solution I described above (existing U-75 and CM2016)
a UVSJ UHF/VHF Combiner/Splitter could be used on the output of the CM2016
to filter out the VHF signal if it is suspected of causing problems on Hi-VHF.

And worse case, separate coax runs with an A/B RF Switch would be needed.....

HD-1080 UHF sidelobes appear to be very low gain...might not be enough
for Norfolk reception AND the main lobe will amplify multipath interference.
The above spec sheet doesn't have enough resolution to see the Gain scale......What a lot of people don't realize, when they look at those unlabeled polar graphs, is that the value of the outer ring is equal to the maximum gain of the antenna, so on a graph for a minimally constructed antenna, that big lobe on the boresight might only represent two or three dB of gain, and what appear, visually, to be substantial sidelobes and backlobes might be depicting negative gain on those axes.

What a lot of people don't realize, when they look at those unlabeled polar graphs, is that the value of the outer ring is equal to the maximum gain of the antenna, so on a graph for a minimally constructed antenna, that big lobe on the boresight might only represent two or three dB of gain, and what appear, visually, to be substantial sidelobes and backlobes might be depicting negative gain on those axes.

Just remember that antenna gain does not have to be positive in order for the signal to be useful.

As long as the resulting signal at the tuner is of adequate power and is free enough from defects it still works.

Most people have a device in their pocket that they use every day that has an antenna with a significant negative gain. Somehow, they still work....

Positive or high positive gain is not the end-all for reception under many conditions when there is adequate signal.

I think that's why I'm afraid of wasting $45 on an RCA ant1650 powered antenna only to have it not get anything I couldn't with my current free one.

Just remember that antenna gain does not have to be positive in order for the signal to be useful.

As long as the resulting signal at the tuner is of adequate power and is free enough from defects it still works.

Most people have a device in their pocket that they use every day that has an antenna with a significant negative gain. Somehow, they still work....

Positive or high positive gain is not the end-all for reception under many conditions when there is adequate signal.

I'll second that. I once put a Terk "tube" shaped antenna on top of a building that is half way between Baltimore and Washington, DC, and it does a yeomanlike job of supplying broadcast DTV signal from seventeen television stations to 47 TVs, but "blah(etc)" is trying to develop off-air channel 12 coming to him over a one-edge signal path with a calculated field strength of -62dBm, and in an apartment, to boot, so I expect that he'll need better VHF performance than that Winegard HD-1080 can give him.

Marcoux VU-graphs (see post 10934), reported a measured Gain of -20.2 dBd for Hi-VHF
and -6.8 dBd for UHF, so I think we should avoid the RCA square antennas.....
[Except for perhaps the ANT2000 Smart Antenna, which is a different design.....]

Although relatively flat, terrain around James City/County near Williamsburg, VA
still varies +/- 50 feet....and we still haven't seen his TVFool results....
There was a significant difference between 10-ft and 25-ft at the zipcode location.

I have a Winegard YA-1713 antenna that I use to pick up Channels 7, 11, and 13 from NYC. While WPIX-11 comes in pretty well (SS > 50%), WNET-13 is marginal (~30%) and WABC-7 only shows up with enhancement. That I get any signal at all is quite remarkable as I am 2nd Edge diffraction and over 60 miles from the broadcast towers (see http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27ee879aaf9b8e).

In any case, I would like to improve my signal if at all possible and I have heard that it is relatively easy to add elements to the YA-1713. So I am looking for advice about how to go about adding elements.

For my first attempt, I took an old unused FM Yagi antenna and removed the front section which consisted of 6 elements each spaced 14 inches apart. The elements on both antenna's appear to be 3/8" tubing, although the boom on the FM antenna is a 1" round tube, while the YA-1713 has a square boom. I cut the elements down to the same size as the YA-1713 elements (24 1/8" end to end) and placed the antenna section in front of the YA-1713 (held in place by a small board). This adds 6 elements and 84 inches to the YA-1713.

So, what kind of gain increase (if any) would I expect to see with this arrangement? When I tested it, I saw no clear change in the Signal Strength as recorded by the signal meter from my tuner (still around 30% for 13 and 50% for 11), however, the signal seemed to fluctuate less and I definitely experienced fewer drop outs. I'm pretty sure the addition is providing a benefit, although perhaps in rejecting multipath rather than increasing gain. Does this seem reasonable?

Finally, I have a few questions about what to do next... Currently, the two antenna sections are electrically isolated (connected only by an insulating board). Should I add an electrical contact? (Note that In both cases the elements are in electrical contact with their respective booms.) Also, I notice that the elements on the YA-1713 have various spacings ranging from 8 15/16" up to 14 13/16". Thus, while the 14" spacings on the extension are in the right ballpark, they are probably not optimal. So what are the optimal spacings for adding 6 additional elements to a YA-1713? Lastly, what kind of benefit would I get by adjusting the element spacing (which would be a lot of work)? If it's only a few tenths of dB, it's probably not worth it, but if it's >1dB I may try it.

Anyway, thanks in advance to anyone who answers my questions.

Since I already had run 4nec2 modeling exercises for my son's YA-1713,
I did some runs with adding 6 (and also 3) Directors, using your dimensions
(taken from a recycled FM antenna with shortened elements).
Yup, there is a moderate 2 dB Gain increase across Ch7-11, close to "optimum".
If the boom length is doubled, the Gain "should" increase nearly 3 dB.

Results for Ch12-13 are indeterminate due to known problems trying to
model the YA-1713 (and apparently other LogYagi antennas).
FWIW, the extended boom didn't seem to be helping...if at all:
http://imageevent.com/holl_ands/wgya1713
All of the Extended Boom plots can be found here, plus the 4nec2 file.

No, I'm not going to attempt any optimization....esp for a few tenths of a dB.

The two boom sections do NOT have to electrically connected together,
nor will it make any significant performance difference.

BTW: As described in my WG YA-1713 folder cited above, I verified via
On-Air tests that there was NO LOSS across Ch13 as found in NEC models.
Here is another On-Air test (from a Dipole to either a YA-1713 or a DIY LPDA)
which verified that there is NO LOSS across Ch13:
http://www.aa6g.org/Lp/tests.html

Here's a situation I'll toss out to all of you guys, Holl_ands, Tower Guy, 300ohm, AntAltMike, et.al...

My TV Fool results are here:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d27ee2edfdb7012

With a Y-10-7-13 and an old model CM4228 I can get every station shown in the list that's stronger than -7.5 dB NM / -98.3 dBm power (except for two, channels 4 and 5, which aren't on the air yet). So reception of the stations is no problem. Recording them is.

I have a Dish Vip-622 DVR which works great for recording OTA, but I have to make sure the antennas are pointed in the right direction at the right time. What I'd like to find is an antenna that will get at least the closer stations - green and yellow sections - without having to use the rotor. Is there such an omni-directional antenna available?

I have the antenna combination mentioned above connected to one side and Antennas Direct C5 and SR-15 antennas coupled together connected to the other side of an A/B switch that feeds the DVR. With the C5/SR-15 I get some of the coverage I'm looking for. With that combination I get all of the stations 24.9 db NM/-66 dBm power or stronger... all of the Sutro stations (267 degrees) and Mt. San Bruno stations (178 degrees), except the low power channel 28, plus I get 36 and 51 from 120 degrees. I think I've got about the best arrangement I can put together, but you guys might have some better ideas, so I'm tossing this out to you to see what you have to offer.

Larry
SF

What I'd like to find is an antenna that will get at least the closer stations - green and yellow sections - without having to use the rotor.

What a challenge! The data is clear, the goal is clear, the solution isn't clear.

I'd start with a channel 12 Jointenna from Amazon.com, couple 12 to the 4228 and forget about recording everything else.

If you can solder, take the Jointenna apart and solder the F connectors to the circuit board before you break something internally.

Tower Guy:
Since he gets Ch12 using his "local" antenna system, why would you
recommend a Ch12 JoinTenna on the "distant" antenna system????
Are you relying on the CM4228 to pick up Ch7...and also Ch9/10
(I don't know...might be too weak)???
And he might lose some of the UHF stations due to the narrower
beamwidth.....

Larry Kenney:
Any comments re Tower Guy's recommendation???

YIKES!!! Those are very strong signals coming from Sutro Towers!!!!
I applaud your current setup.

Did you try an RF Combiner in place of the A/B Switch???
Yes, it will result in a 4 dB loss of sensitivity, but might pick up
SOME (most?) of the stations the CM4228 is pointed towards.
You could also use a set of three A/B Switches as a Bypass
when you want maximum sensitivity (except for loss in switches).

If you have one distant station you want to be "record ready",
you could substitute a JoinTenna or a Single Channel Pass Filter
on the "distant" system instead of the RF Combiner.....with a
3 RF Switch Bypass.

You would for sure need a Variable RF Attenuator on the "local" coax
so the strong signals don't capture the tuner's AutoGainControl.
That might be a good idea anyway.....

A similar arrangement could be done on just the Hi-VHF Antennas,
trying to receive Ch9 (PBS4) & 10 (ABC2) at same time as Ch7&12.
You might have more margin to play with....start by inserting an
RF Combiner on JUST the "distant" coax to see if the extra loss
can be tolerated....

If you have margin to spare, alternatively you might be able to
simply use a lower Gain Hi-VHF Antenna...one with a low F/B Ratio.
Are you interested in a simple DIY project to see if a simple Dipole
radiation pattern is sufficient? The beam would be directed towards
the weakest stations at 52-deg (Ch9/10)....resulting in the reverse
beam being directed towards 232-deg...which roughly splits the
difference between 1Edge Ch12 (178-deg) and LOS Ch7 (267-deg).
Final tweaking may be needed to move the reverse beam 10-20 deg
more towards Ch12, which still leaves Ch9/10 near the max gain.
A Circular Loop has more gain than a Folded Dipole, see instructions:
http://imageevent.com/holl_ands/loops

Comprendez?? Or do you need a diagram of the 3 Switch Bypass????
Can we presume you don't care about Ch2-6???

Thanks for the replies. I tried the Join-tenna and it worked great for 12. Got a signal indication of 33 db, SNR 100%, but I lost all of the UHF stations except those on Sutro Tower... no 27, 36, 41 or 51... so that's why I went to the combination of the C5 and SR-15.

Strong signals from Sutro? Yes... the tower is just 3/4 of a mile away, but surprisingly, adjacent channel reception doesn't seem to be a problem. I receive 35 and 46 from 65 miles away when there are stations on Sutro on 34 and 45!

We can forget channels 2 to 6. There's nothing there now, and only LP stations and translators are due to go on there.

I receive channels 9, 10, 21, 25, 35 and 46 from Walnut Grove using the 10 element yagi and 4228 combo. Signals vary from an average of 23 dB SNR for the strongest (KMAX 21) to 16 dB for the weakest (KVIE 9 and KOVR 25). The others are in between those numbers. I don't get any of the Walnut Grove stations on the C5/SR-15 combo.

I tried the RF Combiner in place of the A-B switch, and the results were pretty dismal. The antennas all seemed to interfere with each other, and as I turned the VHF yagi and 4228, it changed my reception of the stations from both Mt. San Bruno (178 degrees) and the South Bay (120 degrees) and the signals from Walnut Grove (52 degrees) were about 2 to 3 dB weaker... enough to take them frequently below the cliff edge.

I'd appreciate an explanation of using three A/B Switches used as a Bypass for maximum sensitivity. That sounds interesting!

I'll read the information on the Folded Dipole and Circular Loop. Looks like there's lot of information there to absorb.

Larry
SF

Here are the three and single RF Switch configurations...
Variable RF Attenuator reduces the signal level of the "local" antennas.
If you decide to use the single RF Switch configuration, set low atten. for
best "local" reception and hunt around for best "distant" reception setting.
You might even find your "local" reception benefits from some attenuation,
since the 3rd Order Intermod noise is reduced 3 dB for every 1 dB of loss.

I also attached the PowerPoint slide in the zip file so you can change it.

I've saved the jpg file. I'll try it and see what happens.

Larry

Tower Guy:
Since he gets Ch12 using his "local" antenna system, why would you
recommend a Ch12 JoinTenna on the "distant" antenna system????
Are you relying on the CM4228 to pick up Ch7...and also Ch9/10
(I don't know...might be too weak)???


I guess that I missed that he had a local antenna that worked for NBC.

And yes, I expected the 4228 to work on 7 but not 9 and 10.

tballister posted an ON-AIR Ch7/8/13 comparison of CM4228HD
(best UHF & Hi-VHF) to A-D DB8, WG 8000HD and Kosmic SuperQuad,
using A-D C5 and Antennacraft Y10-7-13 as Hi-VHF "standards":
http://www.antennahacks.com/Comparisons/N-Bay_VHF_Shootout.htm
Kosmic SuperQuad is a super-sized 4-Bay+Reflector Screen with
Whisker Length=9.75-in, Bowtie Separation=9.5-in and Tine Separation=5-in:
http://www.dtvusaforum.com/dtv-hdtv-reception-antenna-discussion/8629-kosmic-antennas-superquad-4-bay-bowtie.html

Companion ON-AIR UHF 8-Bay comparison:
http://www.antennahacks.com/Comparisons/CM4228_vs_DB8_vs_HD8800.htm

Some other comparisons:
http://www.antennahacks.com/AntennaComparison.htm

Those spectrum analyzer pictures are great for showing how the various antennas compare. Looks like I made some good decisions with the Y-10-7-13 and the CM4228... they're both winners! For a compact antenna, the new C5 does quite well, too.

Thanks for sharing all of those links with us. I've bookmarked the main page for future reference.

Larry
SF

tballister determined A-D C5 had about 6 dBi Gain for low freqs (e.g. Ch7)
and 3-4 dBi for hi freqs (e.g. Ch13). [Assuming Y-10-7-13 had 10 dBi Gain.]
This is quite a bit less than A-D spec of "Max 8.4 dBi":
http://www.antennasdirect.com/C5-Clearstream-DTV-antenna.html
http://www.antennasdirect.com/pdf/C5-assembly-instructions.pdf

FWIW: When I modeled a Hi-VHF Loop with Loop Reflector, I found
Net/Raw Gain was 7-8 dBi (Ch7) dropping to about 6 dBi (Ch13):
http://imageevent.com/holl_ands/loops/looprefl

For a compact antenna, the new C5 does quite well, too.
Build your own from holl_ands plan for about $15 like jpasedena did. The trick for a smooth loop is just expanding the coil straight from the package. ;)
http://img534.imageshack.us/img534/5243/jpasadenaloopantenna.jpg

300ohm:

Thanks for posting the loop image from our north-of-the-border friends. I couldn't figure out were it was previously posted until I did a Google image search.
http://www.digitalhome.ca/forum/showthread.php?t=112675

Where do I read the net gain?

Where do I read the net gain?

We estimated the net gain to be about 7 dBi across the VHF-hi band.

An update on the build: If I had to do it over again, I would probably go with a 48x48 inch reflector screen, and could use a wider mesh, e.g. 3x2 in. for less weight and wind load. The bigger screen seems to help for those stations that are just at the margin of locking in.

First off jpasdena, as the name implies, is in California, heh.

Where do I read the net gain?
SWR mismatch loss is .51 dbi at SWR = 2.0, and 1.25 dbi at SWR = 3.0. So, just subtract the SWR mismatch loss from the Raw Gain to get Net Gain. (I keep a rough SWR mismatch loss sheet handy to quickly estimate Net Gain without going thru the computation, heh) Keep in mind, most commercial antenna gain figures in the past have been posted in Raw Gain terms.

The formula for Net Gain (which is always less than Raw Gain) is :

NetGain = RawGain+10*log(4*Zr*Zo/((Zr+Zo)^2+Zi^2)

Where;

Zo= the impedence of the feedpoint your designing your antenna to have. Usually this is something that matches a feedline like 300ohm, 75 ohm, 50 ohm...

Zr= the pure resistive part of the total impedence

Zi= the reactive part of the impedence (either +inductive or -capacitive).

jpasadena & 300ohm:

Thanks for the prompt reply with further info. It looks like a winner, and the price is right!

This morning, I was looking for the photos of the one I built, but couldn't find them.

I've been happy with mine. I use it for two stations (8 & 12) that are 34+ miles away LOS and at 24 & 42dB NM. It is mounted on my 48' tower and through about 100' of coax (unamplified).

and the price is right!
The prices for the 1/4" copper tubing and gray electrical pvc are down almost 50% at Home Depot from what they were 18 months ago. :)

About 15 years ago when I moved to a new condo, I inherited two FM antennas that appear to be an AntennaCraft FM6 and an FMSS. Both have baluns attached. Each antenna rig has a 2-sided plastic clip, one side round (holding the balun) and one side square that clips to the square antenna boom. I know the plastic clips did not come with the antenna, but probably with the baluns. Can anyone provide a lead to a supplier for this clip or a balun with the clip included.

I know the plastic clips did not come with the antenna
Are you sure about that ? I would give Antennacraft a call.
http://www.antennacraft.net/FM.html

Guidance for minimum Stacking Distance for a UHF antenna on top of a VHF antenna
as well as stacking identical antennas can be found here:
http://www.avsforum.com/avs-vb/showthread.php?p=14593948

I used 4nec2 to analyze the impact to Gain, SWR and F/R Ratio for the fol. antenna pairs:

a) CM4228 UHF 8-Bay Bowtie on top of K6STI's 5-Element (Full Band Optimized) Hi-VHF Yagi.

b) kgb's 13-Element (Full Band Optimized) UHF Yagi on top of K6STI's 5-Element Hi-VHF Yagi.

Bottom line: 1-3 dB impact to F/R Ratio at 4-ft separation, reducing to < 1 dB at 7-ft.
Impacts to Gain and SWR were minimal, even at closer separations:
http://imageevent.com/holl_ands/stacked
Close to the top of the webpage, you can navigate to individual antenna 4nec2 results.

I didn't use UHF 91XG 4nec2 file due to the extremely large number of wire segments
and difficulties trying to get the file to "converge???" reliability....
And I didn't use Hi-VHF YA-1713 4nec2 file due to SWR problems with both Log-Yagi's I've modeled.

PS: Next, I'll analyze the "optimum" horizontal and vertical spacing for identical antennas.

Great work holl_ands!

I can't image where most of us would be without you. Thank you for the "HUGE" contributions you've made.

I humbly thank you.....but wait....there's more.....

[As long as the beginning of the file names are different, I can run TWO
4nec2 simulations simultaneously whilst plotting results....triple core proc.]
[Anything with a Screen Grid is gonna take 30-60+ minutes.....]

A 4nec2 analysis of EV's Kosmic SuperQuad (9.75x9.5) can be found here:
http://www.avsforum.com/avs-vb/showthread.php?p=18265520

Includes comparison of fol. antennas:
a) CM4228 8-Bay (original, not the new one)
b) Kosmic SuperQuad (9.75x9.5) 4-Bay Bowtie
c) mclapp M4 (9.5x9) Super-4-Bay Bowtie
d) CM4221 (8.5x8.9) (per actual measurements)
e) UTube 4-Bay Defect (~7.5x5.75) (per bobblin5 and makeTV videos)
[PLEASE MAKE SOMETHING OTHER THAN THE UTUBE DEFECT!!!!!]

[As long as the beginning of the file names are different, I can run TWO 4nec2 simulations simultaneously whilst plotting results....triple core proc.]
Yep, and that also works with single core processors, (as long theres enough memory without swapping, which then would take an eternity, heh).

Holl_lands and others interested...

I tried the three switch combining arrangement you proposed. In some ways it's an improvement, but I loose some of the more distant stations in the summed output due to the loss in the couplers I suspect.

Distant signals and locals going right through changed very little in strength, as expected, but when I switched in the summed signals, I lost several dB and that was enough to put four weaker distant stations below the cliff edge. The variable attenuator didn't seem to make much difference at all on the distant stations. It only made the locals weaker, so I took it out of the circuit.

One improvement when using the summed signal output is that I get more stations total. While I can get them either with the local or distant positions, as before, I do lose the weaker ones in the summed output.

It's definitely no worse than before... I still have the same local and distance feeds, and now I have more stations in the summed output feeding the DVR.

Thanks for the design and thought that went into this!

Larry
SF

Holl_ands,

Did you have a chance to finish your modeling of the RCA751/EZ HD antenna? Perhaps I missed the data when you presented it here...

Thanks,

Rick

I just told someone last night that I'd be sending him an e-mail with some links for a "Silver Sensor" style set top antenna. I haven't ever shopped for one. Where can he likely find the best price? eBay is fine, as is Amazon or anywhere else.

I just told someone last night that I'd be sending him an e-mail with some links for a "Silver Sensor" style set top antenna. I haven't ever shopped for one. Where can he likely find the best price? eBay is fine, as is Amazon or anywhere else.

The Philips version is fine if you need UHF only. The Terk HDTVi adds a pair of rabbit ears for VHF.

I've seen the best price for the Philips on Amazon, but that was a while ago.

The Philips version is fine if you need UHF only. The Terk HDTVi adds a pair of rabbit ears for VHF.

He'd probably benefit from the rabbit ears. He is in a 240 unit condo where I set up a headend to remodulate five network broadcasts and one PBS onto analog, but wants to also watch two other, less popular non-profit TV stations, but if he had rabbit ears, he'd also be able to enjoy 7.3 RetroTV


I've seen the best price for the Philips on Amazon, but that was a while ago.
When I Googled for "Amazon" and "Silver Sensor", the first page that came up said it was discontinued and not available, and I wasn't motivated to look much further than that, but I'd say that if someone makes a non-amplified one with rabbit ears, that would serve him best. I'm afraid he'd overload an amplified antenna where he is.

Is this the Silver Sensor you guys are talking about.

http://www.amazon.com/Philips-PHDTV1-Silver-Digital-Antenna/dp/B0007XDI54/ref=sr_1_8?ie=UTF8&s=electronics&qid=1268595456&sr=1-8

I just happened to get an email today about hdtv antennas being on sale at amazon and this came up from the link.

Holl_ands,

Did you have a chance to finish your modeling of the RCA751/EZ HD antenna? Perhaps I missed the data when you presented it here...

Thanks,

Rick
Given similar SWR modeling difficulties with YA-1713 Log-Yagi, I don't think I'm going
to "publish" 4nec2 results for the RCA ANT-751 (aka EZHD) Log-Yagi.
I probably need NEC4 to model the intricacies in the crossover & flat elements.....

Nonetheless, from Gain & F/B results obtained thus far, it appears consistent with
spec sheet for W-G HD-7000R from which it was obviously derived, after cutting
back the lengths & rearranging VHF elements to eliminate Ch2-6 coverage:
http://www.winegarddirect.com/pdf/HD7000R.pdf

Is this the Silver Sensor you guys are talking about.

http://www.amazon.com/Philips-PHDTV1-Silver-Digital-Antenna/dp/B0007XDI54/ref=sr_1_8?ie=UTF8&s=electronics&qid=1268595456&sr=1-8

I just happened to get an email today about hdtv antennas being on sale at amazon and this came up from the link.
PHDTV1 is non-amplified, UHF-only version of Silver Sensor.
Latest Philips SDV2780 is a slightly lower cost Silver Sensor:
http://www.amazon.com/Philips-SDV2780-Indoor-Antenna-Black/dp/B001S0UH4U/ref=sr_1_2?ie=UTF8&s=electronics&qid=1268598373&sr=1-2
http://www.p4c.philips.com/cgi-bin/dcbint/cpindex.pl?ctn=SDV2780/27&slg=en&scy=US

PHDTV3 is amplified VHF/UHF version with RabbitEars:
http://www.amazon.com/Philips-PHDTV3-Indoor-Amplified-Antenna/dp/B000B58VNM/ref=sr_1_1?ie=UTF8&s=electronics&qid=1268597967&sr=1-1
Unless you are a few miles away from broadcast towers, PHDTV3 would be a better choice
due to integration of VHF RabbitEars, better SWR matching, amplification
and a plastic case to keep out inquisitive fingers.....

Silver Sensor, originally from Interference, has also appeared under Zenith label.

He'd probably benefit from the rabbit ears. He is in a 240 unit condo where I set up a headend to remodulate five network broadcasts and one PBS onto analog, but wants to also watch two other, less popular non-profit TV stations, but if he had rabbit ears, he'd also be able to enjoy 7.3 RetroTV



When I Googled for "Amazon" and "Silver Sensor", the first page that came up said it was discontinued and not available, and I wasn't motivated to look much further than that, but I'd say that if someone makes a non-amplified one with rabbit ears, that would serve him best. I'm afraid he'd overload an amplified antenna where he is.

This is the unamplified Terk UHF/VHF antenna:

http://www.amazon.com/Terk-Technology-HDTVi-Indoor-Antenna/dp/B0001FV36E/ref=sr_1_3?ie=UTF8&s=electronics&qid=1268601594&sr=1-3

Hello,

My name is Jason and I ramble.

I’m looking to improve my OTA signal reception. I currently use a Terk HDTVa indoors (second floor) and have it wired to both TVs in my house with very good results. I live at in Milford, MA (approx. 20 miles from the towers of Needham which air the Boston stations and 30 miles from the towers of Rehoboth which air the Providence, RI stations. I get the boston stations fine (90-100%). Providence stations are in the 80s and they often cut out during storms. I like getting the Providence stations because they often air different content during off-peak (non-national broadcast) hours. I was thinking of installing a better antenna in the attic so that I could enjoy these stations even during poor weather. I am not opposed to a roof installation, but if I can get away with a good attic installation, I feel the antenna would last longer as it would be protected from severe wind and rain. Can you help me figure out which antenna to buy?

I would prefer something that can pick up high VHF. Although no Boston stations air on VHF, there are 2 providence stations that air on high VHF (digital channels 12 and 13) and one of them carries MyTV as a subchannel (myTV is not available on any of the Boston subchannels). I do not want to deal with a rotor. =(

Also, has anyone had any experience with the EZ-HD antenna from dennysantennaservice.com ?

Also, is there any reason NOT to get the biggest, baddest antenna you can find? In other words, does it "hurt" at all to get an antenna that does more than you need it to do? Or is that a tremendously stupid question?

By the way, I believe the spread between signal directions (Needham vs. Rehoboth) is probably 90 degrees. Will UHF-only antennas pick up high VHF? Does anyone else live in the Boston area? I think the ION station (virtual 68) is weak. =(

Cheers,
Jason.

Forward Sweep on 4-Bay Bowties analyzed using 4nec2 for:
SuperQuad (9.75x9.5) w Single Angled Grid Reflector and
M4 (9.5x9) w Double Angled Grid Reflector:
http://imageevent.com/holl_ands/multibay/4bayrefl/kosmicswp
http://imageevent.com/holl_ands/multibay/4bayrefl/m4swp
As usual, I have included the 4nec2 files....

There is little difference between M4 (9.5x9.0) with DblAnglRefl and
SuperQuad (9.75x9.5) with SnglAnglRefl, except M4 has about 1 dB
more Gain on lowest channels and SuperQuad can provide a significant
Gain increase above Ch51 if Forward Sweep is 2.0-in (or more).
However, best tradeoff between Gain, F/B & F/R is for BowSwp=1.0-in.

SuperQuad's Optimum Forward Sweep is BowSwp=2.0 for Full Band
and BowSep=1.0 below Ch55 for best Gain.
M4's Optimum Forward Sweep is BowSwp=2.0 either way.
For either antenna, best F/B and F/R Ratios are provided when BowSwp is minimized.

I've tried to model these in accordance with provided "standard" dimensions and hence there
are minor differences between the models.
M4 drawings call for 1/8-in O.D. (AWG9) Copper Elements with AWG12 Feedline,
whereas "as-shipped" SuperQuad Elements and Feedline are both AWG9.

EDIT (19Mar2010 at 1830): Revised M4 element size and Reflector Spacing. Reloaded attachments.
EDIT (23Mar2010 at 1100): Revised SuperQuad Feedline & Element size (AWG9 vice AWG8). Very minor change.

Hi Jason,

Your ramble gave us most of the information needed.

Your tvfool.com report based on Milford looks like this:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3db7c8c7fa71ff18

For more accurate results you can go to tvfool and enter your exact address; the report will not show your exact address if you want to post the URL for it.

Based on the above report I don't see any reason why you can't use an antenna with a lot of gain if it is needed to bring in VHF. The strongest channel at the top of your report isn't near the overload level. If it were, the dBm figure would be in red.

I suggest a VHF-hi (7-13) antenna in the attic for 12 and 13. The VHF antenna and the UHF antenna for Boston can be combined with a UVSJ and then split for more than one TV.

Sometimes there is a problem with overload on VHF from FM stations, but I don't see any problem like that because WGBH is the strongest FM station on your FMfool report which is shown in the attachment. And, your VHF antenna will not be pointed toward Boston. The amount of signal loss caused by being in the attic depends upon the type of construction.

rabbit, thank you. so, I guess I will be getting 2 antennas then. Do you think I'd be able to use something like this (link below) to pick up UHF channels from both boston AND providence?

http://www.antennasdirect.com/C4-Clearstream-DTV-antenna.html
or
http://www.antennasdirect.com/DB2_Indoor_antenna.html

I think they're more "multidirectional" rather than uni, so it might work better for picking up signals from both directions? it's more of a question than a statement as I really don't know what I'm talking about.

Also, do you think I need a signal amplifier or can I probably do without one?

Holl_ands,
I think you miss read the diagrams (http://m4antenna.eastmasonvilleweather.com/Drawings/PDF%20Drawings.html) for the M4 the wire diameter of the whiskers is stated to be around 1/8" or .125" not 1/4". Most people make them using #10 gauge which is .100 or #12 which has a diameter of .080. Not sure how much of a difference that makes but I know double the size will skew the frequency quite a bit.

I also see you used a 5 1/2" reflector spacing the diagrams say 4" - 5" although 3 1/2" to 5 1/2" will work the wider spacing has an overall better SWR but less raw gain some and the 3 1/2" has higher raw gain but a higher SWR.

I'm surprised you are able to get a good model using .250 wires against .080 I've understood that NEC2 modeling programs are not able to model conductor size differences like that accurately unless you do some sort of wire tapering near the junction, especially that junction where you have some pretty extreme angles attaching.

It's odd how your models show the gain for the smaller 9 1/2" X 9" antenna having better gain on the lower frequencies and the larger 9 3/4" x 9 1/2" antenna having higher gain on the higher frequencies. Generally smaller antenna elements mean higher frequency gain especially with the same type of antenna.

Maybe the much fatter whisker wires explain some of that difference.

rabbit, thank you. so, I guess I will be getting 2 antennas then. Do you think I'd be able to use something like this (link below) to pick up UHF channels from both boston AND providence?

http://www.antennasdirect.com/C4-Clearstream-DTV-antenna.html
or
http://www.antennasdirect.com/DB2_Indoor_antenna.html

I think they're more "multidirectional" rather than uni, so it might work better for picking up signals from both directions? it's more of a question than a statement as I really don't know what I'm talking about.

Also, do you think I need a signal amplifier or can I probably do without one?

I had the C4 and it picked up UHF poorly and no VHF.
I replaced it with the CM4228HD to get my channels in two directions.
http://www.amazon.com/Channel-Master-4228HD-Long-Range-Outdoor/dp/B000FVVKQM/ref=cm_cr_pr_product_top

Jason,
Based on Rabbit73's TVFool info almost any piece of metal or wire will pick up a strong enough signal if it is outside. The same is true for an attic install assuming you have the common loss of less than 20 db over outside. The problem you will likely face is multipath either with an omni directional antenna or a directional antenna from any direction other than the one it is aimed at. The higher the gain antennas generally have worse performance in other directions than head on than lower gain but unfortunally almost all antennas have a null 90 degrees from the front.
With all that I would try a small UHF antenna aimed at Boston and a small VHF antenna aimed at Providence combined with a U/V coupler. This will work well for every thing except WJAR, WLNE and WSBE. You might get lucky with some of thoswe three as well.
John

M4 and SuperQuad 4nec2 Results Correction:
Per mclapp comments, I revised M4 element sizes (1/8" O.D.) and
Reflector Separation=4.5", then I uploaded revised attachments (post #10983).

There is little difference between M4 (9.5x9.0) with DblAnglRefl and
SuperQuad (9.75x9.5) with SnglAnglRefl, except M4 has about 1 dB
more Gain on lowest channels and SuperQuad can provide a significant
Gain increase above Ch51 if Forward Sweep is 2.0-in (or more).

SuperQuad's Optimum Forward Sweep is BowSwp=3.0 for Full Band
and BowSep=2.0 below Ch55 for best Gain....
M4's Optimum Forward Sweep is BowSwp=2.0 either way.
For either antenna, best F/B and F/R Ratios are provided when BowSwp
is minimized, e.g. BowSwp=1.0. Take your pick....

Holl_ands,
Thanks for revisiting that, I had never tried to model elements that thick on a bowtie so I wasn't sure what kind of difference it would make. Looks like it makes a fair amount, nice graphs on the effects of different forward sweeps.

Reception problem with HDHomeRun tuners on ATSC Channel 18

Attic mounted HD8200U non amplified antenna, all other tuners on this antenna are tuning channel 18 perfectly.

In HDHomeRun Config (GUI) channel 18 flashes red, yellow and green.

Amplification or attenuation, does not help.

I tried a flat panel indoor uhf antenna (Artec AN2) and channel 18 (local 2.1, 2.2,
and 2.3) all played. The antenna was very directional and the
signal strength was low, but it worked. Appears to only work when I stand next to this flat panel antenna. Also only works when flat panel is 90 degree to the station.

There is channel transmitting on 19. All the channels are from the same compass heading.

Isolated the antenna coaxial cables from router, cat5 cables, and 120 volt sources. Problem persists

SiliconDust support replied to this issue on December 10, 2009; "We have noted a specific issue with this station and suspect that there might be an issue with the broadcast. Your case is being forwarded to our engineering team for review".

CM4228HD has the same behavior as the flat panel antenna I tested earlier. HDhomerun's tunes with antenna pointed 90 degrees off the station, with me standing next to antenna.

Sadelco Displaymax Jr 3000, Signal level meter is reporting all tunable channels within normal spec's between -15 dBmV and +15dBmV

Positioning the CM4228HD so that it has +10dBmV on channel 18 does not resolve the problem.

My current theory is that the HDHomeRun's are picking up interference from channel 19. I will have to get hold of a tunable notch filter and see if I can trap the channel 19 signals.

Any other suggestions or observations?

Notch Filter will also kill adjacent channels....

Where's your report from www.tvfool.com????????????

Notch Filter will also kill adjacent channels....

Where's your report from www.tvfool.com????????????

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3db7c8b944e74197

Other option is to give up on using the HDHomeRun's

HVR-2250 and Avermedia Duet A188 are both working fine on Channel 18.

Reception problem with HDHomeRun tuners on ATSC Channel 18

Any other suggestions or observations?

Perhaps the HDHomeRun is prone to image problems. Channel 32, WBFS, is an image of channel 18. That means that the local oscillator is on a frequency that can receiver either channel 18 or channel 32 (& 33). To prove that theory, a channel 32 notch filter would be needed.

http://home.earthlink.net/~wb9nme/articles/atsc-5.html

Another question.

I'm not sure yet if I'll need a pre-amplifier (I'll be setting up the antenna in the attic to connect to 2 TVs). But if I do, I'm wondering if placement of the amplifier is important. In other words, I could split the signal in the attic and run down to the two TVs, putting the amp right up there at the splitter in the attic. OR, I could run a single signal down to the basement (where I currently have my old cable line coming into a splitter) and use THAT splitter to go back up to the two TVs. The advantage of this second option is that if I decide to put a TV in the basement in the future, I wouldn't have to run any new coaxial, I would just tap right into that splitter. So the second option, I would put the amp at that splitter since I've got a GFCI outlet right there. For the first option, I would need to install a new electrical outlet in the attic (which is not a problem as I am electrically capable).

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3db7c8b944e74197

Other option is to give up on using the HDHomeRun's

HVR-2250 and Avermedia Duet A188 are both working fine on Channel 18.
Since Ch18 and Ch19 are about same signal strength, adjacent channel interference
is NOT a problem (unless Ch19 transmitter is out-of-spec.....)

Likewise Ch32 "Image" or "Taboo" channel is also about same signal strength and
hence "should" NOT be a problem....

Adjacent & "Taboo" channel interference are only a problem when they are MUCH stronger....

Another question.

I'm not sure yet if I'll need a pre-amplifier (I'll be setting up the antenna in the attic to connect to 2 TVs). But if I do, I'm wondering if placement of the amplifier is important. In other words, I could split the signal in the attic and run down to the two TVs, putting the amp right up there at the splitter in ).

It is usually best to put the preamp where the incoming signal is the strongest. Otherwise, you are also amplifying any possible interference, etc. on the down lead.

The amplifiers are powered through the coax downlead.

Perhaps the HDHomeRun is prone to image problems. Channel 32, WBFS, is an image of channel 18. That means that the local oscillator is on a frequency that can receiver either channel 18 or channel 32 (& 33). To prove that theory, a channel 32 notch filter would be needed.

http://home.earthlink.net/~wb9nme/articles/atsc-5.html

I don't understand? How is Channel 32, WBFS, an image of channel 18?

32 is locking fine.

The fact that I can get 18 to lock when the antenna is 90 degrees to station would seem to be a big clue to this problem. Is it possible there is local interference on 497mhz, that only the HDhomerun's pick up?

Tsreader list of PIDs while this HDhomeRun tuner is locked and unlocked on channel 18.

I am not sure if there is any useful information in this text file, but hopefully it has a clue to the problem.

Since Ch18 and Ch19 are about same signal strength, adjacent channel interference is NOT a problem (unless Ch19 transmitter is out-of-spec.....)

Likewise Ch32 "Image" or "Taboo" channel is also about same signal strength and hence "should" NOT be a problem....

Adjacent & "Taboo" channel interference are only a problem when they are MUCH stronger....

I agree that adjacent channel interference is unlikely to be the problem.

Also, image taboo interference shouldn't be a problem for a properly designed receiver. The HomeRun can't be designed properly or it would be working fine.

Without any pre-filtering, the image of a receiver is the same strength as the desired signal. The assumption that an image must be stronger to interfere assumes that there is sufficient front end selectivity to attenuate channel 32. With filter attenuation less than 15 db, the signal from 32 at the same strength as 18 and will interfere with channel 18.

Also consider that TV fool assumes that an omnidirectional transmit antenna is actually omnidirectional. If 18 is weaker than that assumption and another channel is stronger, the interference would be worse than calculated.

I would like some quick advice on a "moon shot" project I'm considering, as to whether it's even feasible.

I live in Cincinnati, and would love to pick up WISH-TV in Indianapolis. I went to Purdue University in Indiana, and Indianapolis news and CBS sports gives them more coverage than Cincinnati stations.

Here's the report from tvfool.com

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3db7c8e1865666a4

WISH-TV is approximately 107 miles away, and the ray path from my antenna to the tower would be via the troposphere. The azimuth angle to Indy is 348 degrees, and there's strong adjacent channel emitters less than 3 miles from my home at 301 degrees. (e.g. WCPO on Channel 10, with the desired signal being WISH on Channel 9)

Of course, I can roof-mount a directional antenna (or I wouldn't even be toying with the idea of this) on a 2nd story roof. I'd plan on hooking up one of the channels on my HD-HomeRun to a dedicated directional antenna aimed at Indianapolis. I could minimize cable run between the antenna and the HD-HomeRun to just a few feet.

Any specialty highly directional, narrow bandwidth antenna designs I could even consider for such a ridiculous project? :-)

I don't understand? How is Channel 32, WBFS, an image of channel 18?

Image Frequency (fimage)

One major disadvantage to the superheterodyne receiver is the problem of image frequency. In heterodyne receivers, an image frequency is an undesired input frequency equal to the station frequency plus twice the intermediate frequency. The image frequency results in two stations being received at the same time, thus producing interference. Image frequencies can be eliminated by sufficient attenuation on the incoming signal by the RF amplifier filter of the superheterodyne receiver.

As a consequence, most Autodyne receivers needed quite elaborate antenna tuning networks, often involving double-tuned coils, to avoid image interference.

http://en.wikipedia.org/wiki/Superheterodyne_receiver

Any specialty highly directional, narrow bandwidth antenna designs I could even consider for such a ridiculous project? :-)

Try a Slingbox antenna.:)

Perhaps the HDHomeRun is prone to image problems. Channel 32, WBFS, is an image of channel 18. That means that the local oscillator is on a frequency that can receiver either channel 18 or channel 32 (& 33). To prove that theory, a channel 32 notch filter would be needed.

http://home.earthlink.net/~wb9nme/articles/atsc-5.html

I will try a notch filter on channel 32.

I live in Cincinnati, and would love to pick up WISH-TV in Indianapolis. I went to Purdue University in Indiana, and Indianapolis news and CBS sports gives them more coverage than Cincinnati stations.
At 107 miles and -25 NM, the signal just isnt there except during tropo events.

They have a website with recaps of the news and videos, so IMO thats your best option.

Psssst: A new Tuner is less expensive than a Ch32 Notch Filter.....

FCC OET conducted Adjacent and "Taboo" Channel interference tests on STB/DTVs available in 2005/6:
http://www.fcc.gov/oet/info/documents/reports/DTV_Interference_Rejection_Thresholds-03-30-07.pdf

CRC, Canada tested five DTVs from 2001-2006, reported in Mar 2010 IEEE Trans on Broadcasting:
http://ieeexplore.ieee.org/search/srchabstract.jsp?tp=&arnumber=5393044&queryText%3Dsalehian+wu+gagnon+interference%26openedRefineme nts%3D*%26searchField%3DSearch+All

For moderate signal strengths, interference from Ch14/15 (Image is 2 channels wide) could be
tolerated when it was stronger by 27-32 dB (worst cases) to more typically 45-60 dB.

Either the Silicon Dust tuner has a defective design.....or Ch18 is putting out garbage PSIP,
as seen in the explosion of "unknown" PIDs in the above TSReader report....
Unfortunately, the report did not include all of the detailed info within each primary PID entry....

BTW: In L.A., KBEH is outputting garbage PSIP, resulting in few DTVs "seeing" their program:
http://www.avsforum.com/avs-vb/showthread.php?t=191672&page=236

WISH-TV is approximately 107 miles away, and the ray path from my antenna to the tower would be via the troposphere. The azimuth angle to Indy is 348 degrees, and there's strong adjacent channel emitters less than 3 miles from my home at 301 degrees. (e.g. WCPO on Channel 10, with the desired signal being WISH on Channel 9)

I'm from Cincinnati and can help with some input.

There's no way you're going to get WISH outside of tropospheric ducting. WCPO is moving from RF 10 to RF 22 in the fall, but you're still too close to the transmitters in downtown Cincinnati to use a pre-amp and too far away from Indianapolis.

I'd focus on trying to get the stations in Dayton. That looks like a better and more achievable challenge. Good luck!

Perhaps the HDHomeRun is prone to image problems. Channel 32, WBFS, is an image of channel 18. That means that the local oscillator is on a frequency that can receiver either channel 18 or channel 32 (& 33). To prove that theory, a channel 32 notch filter would be needed.

http://home.earthlink.net/~wb9nme/articles/atsc-5.html

Positioned the flat panel antenna so that the HDHomeRun tuner would lock channel 18, (90 degrees to station, handheld?) at the same time I scanned the signal level on each channel with a Sadelco DisplayMax Jr 3000. Guess which channel is missing any signal.... 32

As soon as I reposition the antenna and channel 32 regains signal, channel 18 unlocks

Psssst: A new Tuner is less expensive than a Ch32 Notch Filter.....

FCC OET conducted Adjacent and "Taboo" Channel interference tests on STB/DTVs available in 2005/6:
http://www.fcc.gov/oet/info/documents/reports/DTV_Interference_Rejection_Thresholds-03-30-07.pdf

CRC, Canada tested five DTVs from 2001-2006, reported in Mar 2010 IEEE Trans on Broadcasting:
http://ieeexplore.ieee.org/search/srchabstract.jsp?tp=&arnumber=5393044&queryText%3Dsalehian+wu+gagnon+interference%26openedRefineme nts%3D*%26searchField%3DSearch+All

For moderate signal strengths, interference from Ch14/15 (Image is 2 channels wide) could be
tolerated when it was stronger by 27-32 dB (worst cases) to more typically 45-60 dB.

Either the Silicon Dust tuner has a defective design.....or Ch18 is putting out garbage PSIP,
as seen in the explosion of "unknown" PIDs in the above TSReader report....
Unfortunately, the report did not include all of the detailed info within each primary PID entry....

BTW: In L.A., KBEH is outputting garbage PSIP, resulting in few DTVs "seeing" their program:
http://www.avsforum.com/avs-vb/showthread.php?t=191672&page=236

So if the problem these HDHomeRun tuners are having are with the Taboo channel 32. What was done wrong in the design of the tuners?

Perhaps the HDHomeRun is prone to image problems. Channel 32, WBFS, is an image of channel 18. That means that the local oscillator is on a frequency that can receiver either channel 18 or channel 32 (& 33). To prove that theory, a channel 32 notch filter would be needed.

http://home.earthlink.net/~wb9nme/articles/atsc-5.html

How would someone with HDHomeRun tuners in a different location be able to check TVfool and determine which channels in their location are "Image Frequencies"? Is there a math formula?

Is this the formula?

How would someone with HDHomeRun tuners in a different location be able to check TVfool and determine which channels in their location are "Image Frequencies"? Is there a math formula?
As I said above, Image Freq will be 14 and 15 channels ABOVE desired UHF channel number.

Math formulas were in the wiki article....

As I said above, Image Freq is two channels wide (cuz involves mixing w 2nd harmonic)
and will be 14 and 15 channels ABOVE desired UHF channel number.

Math formulas were in the wiki article....
No, it has nothing to do with the 2nd harmonic. It's just that the IF frequency for the center of the channel is 43.5 MHz. 43.5 * 2 = 87 MHz, but 87 / 6 = 14.5. The image is only one channel wide, but it's halfway between two channels. So both the 14th and 15th channel above the desired channel can cause image interference.

Ron

That formula is correct....for an AM Tuner using an IF frequency of 455 kHz.
And 10.7 MHz IF frequency is commonly used in FM Tuners....

"Most" DTV Tuners have used an IF frequency of about 44 MHz, so twice
that is 88 MHz, or a UHF channel number difference of 14.67 (e.g. 14-15 channels UP).

F(image) = F(desired) +/- 88 MHz.

Here are some Single Conversion Tuners with IF=44 MHz. The varactor tunable filter on the
RF input is the primary means to attenuate the image frequency:
http://www.infineon.com/dgdl/AppNote_TUA6034_PartIII_ATSC.pdf?folderId=db3a304412b4079501 12b41fb6f4376f&fileId=db3a304412b407950112b41fb7563770 ["Typical" Schematic.]
https://fjallfoss.fcc.gov/oetcf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout=500&calledFromFrame=N&application_id=406918&fcc_id=%27BEJ9QKE00710%27 [Used in early Zenith/Insignia CECBs.]
http://www.compendiumarcana.com/forumpics/Tivax%20STB-T9.pdf [Analog Pass-Thru CECB.]
http://www.haluyatech.com/down/lgtunner/TDVS-H066F.pdf [See example on pg9.]

However, some newer tuners have used either a much lower IF, making it possible to use a
much lower sampling frequency to get the signal into the ATSC Decoder chip (a high speed
signal processor) to implement the IF Filter job, rather than an external SAW filter.....or both:
http://www.sony.net/Products/SC-HP/cx_news/vol56/pdf/featuring56.pdf
http://www.rfdesignline.com/howto/207100201;jsessionid=OVPM3GSKIG3CLQE1GHPSKHWATMY32JVN?pgno=2
When a low IF freqs (or zero IF, Direct Conversion tuner) is used, excellent I/Q matching
in the signal processor chip's A/D Converter is essential for image rejection performance.

Microtune, some Samsung and a few others have gone the Double Conversion route:
http://www.odyseus.nildram.co.uk/Systems_And_Devices_Files/SuperHet.pdf
http://rfdesign.com/images/archive/0601Norsworthy67.pdf
Found in some USB Sticks and various other STBs & DTVs, I have yet
to see any test of how well they perform with very strong signals on
the input....and NO RF input filter to attenuate them prior to the mixer.

That formula is correct

This is the tuner which my HDHomeRuns should have by ID number;

Tuner
JINXIN
UVS1805BDMW1
0803-2527

demodulator chip
Micronas DRX 393yJ

whereas the earlier ID HDHomeRuns (Before 1013xxxx) had;

Tuner
Thomson DTF8640B

demodulator chip
Oren CAS220

I am wondering if the earlier tuners were able to reject this "Image Frequency".

Calling all HDHomeRun owners. Can you tune with Image channels?
http://www.avsforum.com/avs-vb/showthread.php?p=18365396#post18365396

JINX UVS1805 series NIM "specs" (such as they are):
http://www.jx-e.com/en/Productsviwe.asp?id=39
Noise Figure < 10 and VSWR < 7 are pretty pathetic....perhaps indicative of overall performance....
UVS2605 Series has slightly better Noise Figure < 8 and VSWR < 7.
[VSWR of SEVEN!!!!! That's the worst I've ever seen in ANYTHING!!!!!]

www.micronas.com no longer posts information re their ATSC Decoder chips
and Google came up empty wrt DRX393....or DRX394.
A long time ago I snagged a spec sheet for DRX394 ATSC Decoder....but it's from 2005.
So the DRX393 is somewhat of a mystery.....
BTW, DRX390 and DRX396 are RF Tuner chips, so third digit is part TYPE.

===================================
www.thomson.net website had been taken over (hostile???) by the Technicolor coalition.
However my copy of the earlier DTF8640A spec sheet claims conformance to ATSC A/74 "Guidelines"
and an Image Rejection of 60 dB (minimum on UHF, more on VHF).

Oren was taken over by Zoran in 2005. Here's the CAS220 (Cascade 2) spec sheet:
http://www.zoran.com/IMG/pdf/Cascade2.pdf

FWIW: CAS220 and an unidentified Thomson tuner were used in the original RCA DTA800A CECB.
Hmmmm....a similar design might have been used in the HomeRun.....

"DTV Converter Box Test Program--Results and Lessons Learned", 9 Oct 2009
is now available on FCC OET Documents webpage. This is a statistical analysis
(no manufacturer names) summarizing how well the (100+) CECB's performed against
NTIA specs, including sensitivity, adjacent/taboo channel interference susceptibility, etc:
http://www.fcc.gov/oet/info/documents/reports/9TR1003-ConverterBoxTestReport.pdf

This is the FIRST test to compare Single Conversion to Double Conversion Tuners.

For comparison purposes, they have also included charts from 2005/2006 test of STB/DTVs:
http://www.fcc.gov/oet/info/documents [See FCC/OET 07-TR-1003.]

CRC, Canada also released results of their adjacent/taboo channel test in this month's
IEEE Transactions on Broadcasting, Mar 2010 [Subscription required...or a good Library]:
http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=5393044&queryText%3Dsalehian+atsc-dtv+receivers%26openedRefinements%3D*%26searchField%3DSearch +All

No, it has nothing to do with the 2nd harmonic. It's just that the IF frequency for the center of the channel is 43.5 MHz. 43.5 * 2 = 87 MHz, but 87 / 6 = 14.5. The image is only one channel wide, but it's halfway between two channels. So both the 14th and 15th channel above the desired channel can cause image interference.

Ron
Sorry, you're right....it isn't a second harmonic problem.....

Since "most" ATSC tuners I've seen use 44 MHz (center freq), Ch18 (494 MHz)
would use 494 + 44 = 538 MHz oscillator freq with image at 538 + 44 = 582 MHz,
which is (582 - 494)/6 = 14.67 channel positions away.....with 6 MHz bandwidth.

Tower Guy and Holl_ands, Thanks for all your help.

I appreciate your time and efforts.

"DTV Converter Box Test Program--Results and Lessons Learned", 9 Oct 2009
Lesson learned : Digital TVs before 2007 had really crappy tuners, heh.

Lesson learned : Digital TVs before 2007 had really crappy tuners, heh.

+1.

Life is so much better in my house now with a good quality ATSC tuner.

Tower Guy and Holl_ands, Thanks for all your help.

I appreciate your time and efforts.

You're welcome. You had a very interesting problem. I'm glad that my wild guess was right!

Hi everyone

Sorry if a question like this has been posted before, but I have a question about how jointennas work in certain configurations.

I'm in the process of designing an antenna setup for the duplex I live in. Since there is more than one tenant here, a rotor system is unworkable, and since the twoers are in two directions here (one tower is about 180 degrees from the others), I am more than likely going to go with a two-antenna system, with a join-tenna injecting the channel off the single-channel antenna.

I asked on another forum for advice on which antennas I should use and how they should be configured. The resident expert there suggested that I hook the two antennas up with a jointenna, but backwards. That is, the broadband antenna hooked up to the single channel input and the single channel antenna hooked to the broadband input. He suggested this because the channel that the single channel antenna is to pick up, channel 19, is very near a channel that the braodband antenna is supposed to get: channel 21.

My question is first off, if this will work as he described, and also how it works. I consider myself technical minded and curisoty is starting to eat me up on this.

Thanks for any advice you guys can give!

He suggested this because the channel that the single channel antenna is to pick up, channel 19, is very near a channel that the braodband antenna is supposed to get: channel 21.

My question is first off, if this will work as he described, and also how it works. I consider myself technical minded and curisoty is starting to eat me up on this.


A Jointenna is not sufficiently selective to allow channels 19 and 21 through either port simultaneously, but it may work anyway if the signals are strong enough. I'd try it first installed as intended.

Tinlee can design a perfect filter for you.
http://www.tinlee.com/Matv_filters.php?active=3
It will be more effective than a Jointenna, but also more money.

and since the twoers are in two directions here (one tower is about 180 degrees from the others), I am more than likely going to go with a two-antenna system

Post your TVFool image.

Maybe youre close enough to go with a reflector-less antenna ?

If not, another option may be two preamped antennas into two separate coax downleads, which are each then split, then two coax leads into each house (one from each antenna), which then go into A-B switches at each of the TVs.

Post your TVFool image.

Maybe youre close enough to go with a reflector-less antenna ?

If not, another option may be two preamped antennas into two separate coax downleads, which are each then split, then two coax leads into each house (one from each antenna), which then go into A-B switches at each of the TVs.

TV Fool Image here: http://i110.photobucket.com/albums/n94/avder42/Radar-All.png

The channels I care about are channels 2, 21, 19, 13, 38, and 44. The analog channel listed on channel 2 is in that direction, but it actually operates on channel 33, so I dont need low-VHF at all, just high-vhf for channel 13. Channel 35 in the same direction as 19 is completely discardable as its just a low power religious station leaving just channel 19 in that direction and the rest except for 33 about 180 degrees the other way.

Stampeder updated his chart of antenna recommendations:
http://www.digitalhome.ca/forum/showthread.php?t=97121
Although some others could be added, I don't disagree with what's in the list....
These are "the best" choices...note addition of RCA ANT751 in new "small" category.

PS: Although he indicates Hi-VHF antennas have "No FM Radio"
since the FM band is well below Ch7, any ol' piece of metal is going
to receive the stronger FM stations.....although SWR will be very high.

The channels I care about are channels 2, 21, 19, 13, 38, and 44. The analog channel listed on channel 2 is in that direction, but it actually operates on channel 33, so I dont need low-VHF at all, just high-vhf for channel 13. Channel 35 in the same direction as 19 is completely discardable as its just a low power religious station leaving just channel 19 in that direction and the rest except for 33 about 180 degrees the other way.
Heh, that makes it easy. Build yourself just (1) reflector-less Single Bay GH with 28 inch NARODs (for channel 13). Should set you back about $10. Then use the savings to get a QUALITY low noise preamp to over come cable and splitter losses between the two houses.

Basically build the SBGH as per here : http://mysite.verizon.net/res11d41p/index.html

except,

you dont need the reflector and you dont have to use the Top Hat NAROD, straight 28" ones will be fine in your situation.

If you dont want to build, you could get an AntennaCraft G1483 and rip off the reflectors and put NARODs on it. But that will cost more, and the time savings wont be much. At 56.2 NM, theres a good chance youll get channel 13 even without NARODs. The NARODs will insure that you do.

Hi everyone

My question is first off, if this will work as he described, and also how it works. I consider myself technical minded and curisoty is starting to eat me up on this.

Thanks for any advice you guys can give!

To answer how the Jointenna works. The Jointenna is tuned by hooking it up to a network analyzer. There are three reference markes set at 500MHz, 503MHz and 506MHz. The Jointenna is then plugged in to the selected channel input and the signal is peaked as much as possible. This will still have a slope effect, and the adjacent channels can be affected. Then the analyser is hooked to the all channels input. The Jointenna is then tuned to trap out the selected channel. Usually the middle frequency for channel 19 would be 503MHz would be ttuned for a loss of at least an atenuation of 20dB. That is a basic overview of how the Jointenna is tuned and what it does.

Heh, that makes it easy. Build yourself just (1) reflector-less Single Bay GH with 28 inch NARODs (for channel 13). Should set you back about $10. Then use the savings to get a QUALITY low noise preamp to over come cable and splitter losses between the two houses.

Basically build the SBGH as per here : http://mysite.verizon.net/res11d41p/index.html

except,

you dont need the reflector and you dont have to use the Top Hat NAROD, straight 28" ones will be fine in your situation.

If you dont want to build, you could get an AntennaCraft G1483 and rip off the reflectors and put NARODs on it. But that will cost more, and the time savings wont be much. At 56.2 NM, theres a good chance youll get channel 13 even without NARODs. The NARODs will insure that you do.

I've actually been pondering throwing together a multi-bay bowtie antenna that Ive found directions for all over the internet just to see what that could do, and then using a VHF/UHF diplexer to connect a cheap set of rabbit ears to it for channel 13.

Is there a cheap design for this that would actually stand up to the elements in an outdoor situation? Keep in mind that I live in the Fargo, ND-Moorhead, MN area, and the winters here are brutally cold, snow filled, and the whole year round is very windy, so the materials used would have to be somewhat durable.

And if it is possible to build one of those on the cheap for outdoors, what would you recommend as far as a preamp goes? Would any further distribution amplifier be needed after the preamp? Also, another factor to consider is that, to save time and effort from cabling, I would like to diplex this into the cabling that was recently installed when we got satellite service. I've already done my homework on that as far as researching if OTA and Satellite would be compatible in my situation, and they are if I install the right equipment, which I plan to.

To answer how the Jointenna works. The Jointenna is tuned by hooking it up to a network analyzer. There are three reference markes set at 500MHz, 503MHz and 506MHz. The Jointenna is then plugged in to the selected channel input and the signal is peaked as much as possible. This will still have a slope effect, and the adjacent channels can be affected. Then the analyser is hooked to the all channels input. The Jointenna is then tuned to trap out the selected channel. Usually the middle frequency for channel 19 would be 503MHz would be ttuned for a loss of at least an atenuation of 20dB. That is a basic overview of how the Jointenna is tuned and what it does.

Right, I know the basics of how it works, but I was wondering about the logic of his suggesting I hook it up backwards and his assertion that it would work as intended: allowing both channel 19 and channel 21 through.

Antenna construction threads are found here:
http://www.avsforum.com/avs-vb/showthread.php?t=798265
http://www.digitalhome.ca/forum/forumdisplay.php?f=186
http://www.digitalhome.ca/forum/forumdisplay.php?f=81
Note that the latter two include ample participation from our Northern Neighbors....

A Preamp should be adequate unless you're feeding more than 4 or 8 drops.
Cascading a Distribution Amp after a Preamp could cause overload problems.
I have an app for that: http://imageevent.com/holl_ands/files/ota

Careful research is needed if you want to Diplex OTA and SAT.
Dishnet uses a "Super Home Node", incl. Multi-Room signal distribution:
http://www.avsforum.com/avs-vb/showthread.php?p=18147063

Dishnet freqs do NOT overlap OTA freqs....but many HD DirecTV systems DO....be very careful....

I've actually been pondering throwing together a multi-bay bowtie antenna that Ive found directions for all over the internet just to see what that could do
I wouldnt waste your time, its a poor performer. Holl_ands analysis here : http://imageevent.com/holl_ands
A SBGH is also quicker to construct, its just 2 pieces of wire (4 counting the NARODs).
Is there a cheap design for this that would actually stand up to the elements in an outdoor situation? Keep in mind that I live in the Fargo, ND-Moorhead, MN area, and the winters here are brutally cold, snow filled, and the whole year round is very windy, so the materials used would have to be somewhat durable.

People much further north than you have been using reflector GH's just fine. A reflector-less SBGH, with its less wind and snow load, built using 6 gauge copper or 1/4" aluminum rod, and the cheap electrical grey pvc EMT should be fine even for Antarctica, heh. (although I cant find specs for the minimum temp for the grey pvc EMT. Max temp is 90 C)

There are designs for excellent 4-Bay Bowties on the Internet....but the overly small designs in
babblin5's UTube video, as well as others (e.g. MakeTV) are extremely poor (see analysis cited below).

References to the GOOD 4-Bays, such as mclapp's M4 (9.5x9.0) and EV's SuperQuad (9.75x9.5)
can be found in the individual simulation reports....& compares favorably to SBGH:
http://imageevent.com/holl_ands/multibay

Which will hold up to wind and ice loading better??? A professional broadcast antenna....

I would bet on a well-built SBGH, since it is difficult to support the ends
of the 4-Bay whiskers....unless you attached each to yet another pair of PVCs,
which may or may not affect the antenna....or use 1/2-in Copper tubing for strength....

Which will hold up to wind and ice loading better??? A professional broadcast antenna....

I would bet on a well-built SBGH,
Yeah, and with the NARODs to interlock the whole thing together, its a very sturdy structure.

RF Splitter Mod for the original CM4228, 4nec2 analysis using Ken Nist's model:
http://imageevent.com/holl_ands/mult...refl/cm4228mod
Including AT LEAST another 0.5 dB loss in a typical RF Splitter (when signals are perfectly matched
in both amplitude and phase), I didn't see very much of a difference in Net Gain up thru Ch51,
although the RF Splitter Mod has 1 to 3 dB higher Raw Gain on the lowest channels and
1-3 dB more gain on the highest channels.

Hi-VHF Raw Gain on Ch7-13 was 8.5 to 9.2 dBi, except for a dip to 3.5 dBi on Ch11.
However SWR was very excessive below Ch12 & 13.

Note: A DUAL BEAM pattern results, with a null in between, if one of the Baluns is reversed.
The Gain in each beam is about 2.4-2.9 dBi lower than the usual Single Beam pattern. Perhaps
there is a situation where the tower groups are separated by about 50-degrees.....

The RF Splitter Mod would work even better with Super-Sized 8-Bay Bowties, as the
max Gain remains about the same, but moves down in frequency by about 100 MHz.....

So what I did today as a crafts project was build one of the 4-bay bowtie designs holl_ands linked to, the 8.5in whisker design because thats all my sacrificed clothes hangers would allow, and those were the only hangars I could spare or I would have built a 9.75in one. I'm quite pleased with the results so far over my old rabbit-ears/loop combo. 4.1 went from 2-3 bars (my TV does zero to 4 bars for signal strength) to 3-4 bars, 6.1 stayed at 4 bars, 11.1 went from one bar to 2-3 bars, 13.1 remained where it was with rabbit ears at 3 bars, and 15.1 is at 3 bars. Analog low power channels 35 and 33 both showed improvement, with 35's picture and audio getting close to clear, and 33's picture is visible, but its audio is still all static.

This antenna is a purely indoor build of course, just coat hangers on a piece of ply-wood I found downstairs. I plan on doing a very precision build with one of the Reflectorless SBGH+Narod designs and then seeing if I can find a good way to mount and ground it outdoors near my satellite dish and seeing what that gets me on one TV. If the results are satisfactory I'll add a preamp and do all 6 drops.

Perhaps the HDHomeRun is prone to image problems. Channel 32, WBFS, is an image of channel 18. That means that the local oscillator is on a frequency that can receiver either channel 18 or channel 32 (& 33). To prove that theory, a channel 32 notch filter would be needed.

http://home.earthlink.net/~wb9nme/articles/atsc-5.html

Got a Winegard UT-2700 adjustable notch filter, set it up to block channel 32 and channel 18 tunes fine now.

Pretty solid evidence that these (HDHomeRun) tuners are susceptible to the "Image Frequency" problem.

EDIT - channel 18 is working today with out blocking channel 32. First time channel 18 has worked since I bought these HDHomeRun units in December 2009. Something changed in the source??

Attached below is a PDF file for three different TV antennas, Antennas Direct 91XG, Winegard HD-9032 and YA-1713. I’ve taken data from the sites of the manufactures, redrawn their polar charts and some of the artwork. Antennas Direct did not have a polar graph that I could find. The graphics shown below represents what the PDF looks like.

DISCLAIMER: I am not a graphic artist so no snide remarks please :)

http://farm3.static.flickr.com/2721/4448386583_97e9b0f411_b.jpg

http://farm5.static.flickr.com/4035/4448994896_95dab37521_b.jpg

http://farm5.static.flickr.com/4005/4448994898_70ddd9cfe1_b.jpg

We had one installed in 1968. Sears sold it and it was mounted 42 feet high. We lived in Downers Grove, Il. And watched the Bear football games that were blacked out from Wbbm analog 2. from Rockford ,ILL.. And sometimes South Bend. Did some DX tests and did have some thrilling fun. I was wondering if anyone had a Sears catalog from that year with the JFD antenna listed? Oh we used a Blonder-Tongue Uhf pre-amp 10 or 13 db gain cant recall which figure.Thanks again for the heart warming posts from the era when things worked well and lasted. I would love to have one again.

JFD's Zig-A-Log UHF Antenna can be found in fol. catalog excerpts:
http://www.digitalhome.ca/forum/showthread.php?p=1009255
http://www.digitalhome.ca/forum/showthread.php?p=1074407
It's an array of four Zig-Zag LPAs (Log Periodic Antennas) in a
trapezoidal configuration.....all with Horizontal Polarization....

And here are some photos of a Zig-A-Log submitted by Systems2000:
http://www.avsforum.com/avs-vb/showthread.php?p=16702814
In post#9671 I provided some explanation....

Hi-VHF 2-Bay and 4-Bay Bowties (NO Reflectors) were analyzed to find quasi-optimum (33"x32")
dimensions (overall 49" H x 33" W and HUGE 113" H x 33" W respectively):
http://imageevent.com/holl_ands/multibay
I also analyzed response in the UHF Band...yes there is good Gain...but it's all over the place...

These NO Reflector versions would be suitable for hanging on the wall behind a picture or curtain....

Hi-VHF 2-Bay NO Refl: 7.5-10.0 dBi Raw Gain, SWR 2.2-3.5 with AWG10 (Fatter would be better).
Hi-VHF 4-Bay NO Refl: 10.8-12.3 dBi Raw Gain, SWR 1.1-2.8 with AWG10.

Compare to:
Hi-VHF Folded Dipole: 2.1-2.2 dBi Raw Gain, SWR 1.1-2.5 with AWG12.
Hi-VHF Circular Loop: 3.5-4.5 dBi Raw Gain, SWR 1.7-2.6 with AWG12.

I got an RCA Ant1650 and it's worse than my free rabbit ear unpowered antenna...

Up in Angola,Indiana. 40 miles north, A few 12 bow reflector antennas are still up on homes. I must investigate. Thank you for the links on the zig a log JFD.

I Really want only WTTG real Channel 36 vitual 5.1 and WUSA real 35 20.1 vitual Both 94 miles away... I am considering Winegard HD 7084P,Winegard Model:HD 8200U,Advantage CM-3020,Ultra-Hi Crossfire CM-3671 and CM-7777...Any suggestions do you think this is possible?

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9c6bd16aa3c7c2

I Really want only WTTG real Channel 36 vitual 5.1 and WUSA real 35 20.1 vitual . . . . . do you think this is possible?

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9c6bd16aa3c7c2Unfortunately, these channels would be impossible to receive at your location.:(

I Really want only WTTG real Channel 36 vitual 5.1 and WUSA real 35 20.1 vitual Both 94 miles away... Any suggestions do you think this is possible?

WITF on channel 36 located near you makes reception of another channel 36 impossible.

WUSA is actually on channel 9, not 35 (they were on 34 until 6/12/2009). The adjacent channel interference from WGAL on channel 8 precludes reception of WUSA on channel 9.

The reference to channel 20.1 doesn't make sense to me.

The reference to channel 20.1 doesn't make sense to me.I assumed the OP was referring to WDCA 20.1 (RF35)

JINX UVS1805 series NIM "specs" (such as they are):
http://www.jx-e.com/en/Productsviwe.asp?id=39
Noise Figure < 10 and VSWR < 7 are pretty pathetic....perhaps indicative of overall performance....
UVS2605 Series has slightly better Noise Figure < 8 and VSWR < 7.
[VSWR of SEVEN!!!!! That's the worst I've ever seen in ANYTHING!!!!!]


I have one of these newer HDHRs, and it is the worst tuner I've used in years. I have a bunch of LGDT3303 based PC tuners, some as old as 5 years, and they all outperform the HDHR by a wide margin. But I really, really like the concept of an HDHR and I want to make it work. Is there anything I can do to compensate for its bad specs?

In my setup, I have an attic mounted CM4228, 25' of RG6, and a 4-way amplified splitter. I live about 17 miles from the transmitters that I'm interested in, and the CM4228 is aimed at the transmitters. I live about 5 miles from a commercial aviation airport (RDU), and depending on weather, the flight path is sometimes between me and the transmitter.

After re-locating the antenna several times (first time I've had to touch it since I got my LG tuners in 2005), I've got a decent signal on the HDHR across most of my stations. Oddly, my best stations are physically on VHF 11 and UHF 17, and my worst are on UHF 48 and UHF 49. These problem stations show lower signal strength in the HDHR stats, and are more prone to breakups. But even the "better" stations have occasional glitches.

The way things are now, I see a few glitches per hour. I'd like things to be perfect, the way they are with my LG based tuners. After about 12 hours of being tuned, I see the following stats:

Fri Apr 9 09:55:26 EDT 2010
tun: ch=8vsb:17 lock=8vsb ss=88 snq=99 seq=100 dbg=2048-11677-1429
dev: resync=9115 overflow=0
ts: bps=19395584 ut=97 te=7403 miss=41 crc=1
flt: bps=2433472
net: pps=234 err=0 stop=0

tun: ch=8vsb:49 lock=8vsb ss=84 snq=100 seq=100 dbg=2048-11572-1312
dev: resync=40659 overflow=0
ts: bps=19394080 ut=89 te=29234 miss=109 crc=0
flt: bps=3581024
net: pps=349 err=0 stop=0

What should I look at to improve my setup? I really don't want to move the antenna out of the attic. Aside from that, I'm all ears.

Thanks,
Drew

Has anyone tried this indoor/outdoor antenna from Monoprice? any impressions? I think I am going to try it - the rabbit ears that I have right now are not consistant...seems a lot of people get good results with this even being used indoors...

http://www.monoprice.com/products/product.asp?c_id=109&cp_id=10901&cs_id=1090102&p_id=4730&seq=1&format=2

drewwho: You might be interested in the Ceton InfiniTV 4, a Quad ATSC/QAM Tuner PCI card:
http://www.cetoncorp.com/products.php
Website is accepting pre-orders now for shipments beginning 31May2010.
It also supports a CableCARD for decrypting digital cable channels.....

Hello AVS World,
So my wife and I have finally had enough of Time Warner's crap. We are switching to netflix + antenna. I would appreciate a recommendation from the experts on which antenna to get. Here are the details of our situation.

2 TV's: One Samsung LN46A650 (using it's built in tuner)
One old SD RCA TV (using a TIVAX STB-S8 tuner)

On the second floor of an apartment building with the balcony facing North.

h++p://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9c6ba53d862144

Ideally we would like to pick up at least ABC, NBC, CBS, FOX. Anything above that would be a plus.

Thanks in advance for your recommendations. :)

Hello AVS World,
So my wife and I have finally had enough of Time Warner's crap. We are switching to netflix + antenna. I would appreciate a recommendation from the experts on which antenna to get. Here are the details of our situation.

2 TV's: One Samsung LN46A650 (using it's built in tuner)
One old SD RCA TV (using a TIVAX STB-S8 tuner)

On the second floor of an apartment building with the balcony facing North.

h++p://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9c6ba53d862144

Ideally we would like to pick up at least ABC, NBC, CBS, FOX. Anything above that would be a plus.

Thanks in advance for your recommendations. :)

Switch to an apartment that faces south. Whatever you might receive will have to come through your building to get to your antenna, so there are no good prospects without knowing the details of your building's construction.

Good luck.

Switch to an apartment that faces south. Whatever you might receive will have to come through your building to get to your antenna, so there are no good prospects without knowing the details of your building's construction.

Good luck.

Brick exterior, 3 stories tall. There is essentially a hallway corridor (open air on both ends) and another apartment (400 ft wide) between me and the exterior wall facing the towers.

Perhaps my best bet is to throw up one of these...

h++p://www.monoprice.com/products/product.asp?c_id=109&cp_id=10901&cs_id=1090102&p_id=4730&seq=1&format=2

... on the patio and see what I can get. Not sure if the amp will mess with the QAM DTV tuner in the Samsung TV. The antenna seems to get good reviews.

I'm located in Beaverton OR and looking to mount an antenna in the attic of a 2 story wood house. I've got lots of large pine trees between the house and the broadcast towers. Here's the TVFool report:


http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9c6b49eead92e3

Any suggestions for a suitable antenna would be appreciated.

pdxmcad:

Your signals are very strong, so you don't need an amplified antenna. An amplifier might cause overload. The big unknown is how much attenuation of the signals is caused by the attic. Trees that are close are worse than trees far away. You need to try different locations in your attic for best results.

Just for fun, you could try the Radio Shack Catalog #15-1874 rabbit ears and loop antenna in the attic first. You can return it if it doesn't work, but I suggest keeping it around for experiments because it's not very expensive:
http://www.radioshack.com/product/index.jsp?productId=2103077

Moving up to a better antenna, my suggestion is the Winegard HD7694P:
http://www.winegard.com/offair/index.php

Hi guys. I was wondering if there is any realistic way I could receive channels KVRR 19 and WDAY 21 (tvfool image attached as i cant post links yet)

We have an older Radio Shack combo antenna from 8-10 years ago with a recently added CM7777 preamp and a small boosted splitter between TV's.

I am obviously in a bad area for reception and before the addition of the CM7777 we only got 5 stations, the preamp added 3 more and boosted the signal on WDAY 21 to 55% but its not enough to lock onto the signal. I assume its a lost cause but there are very little TV choices around here, its either analog translator stations or sattelite TV which we would rather not have to pay for as there is no cable ran this far out. Thanks in advance.

Realistically and consistant, nope. Theyre just too far and too weak. Youll still get them under Tropo conditions.

a recently added CM7777 preamp and a small boosted splitter between TV's.
That boosted splitter is probably doing more harm than good. Try a simple normal splitter instead and see if you dont get a little better reception.

iScar,
Based on you TVfool plot as 300ohm said your chances are not good but I've seen those plots to be off a bit so lets base your chances on what you actually receive with your current equipment.

How big is that RS antenna, some of those Radio Shack antennas were decent and some were junk. In any case there are antennas available that will out perform most any RS offering. If you could post a picture of your RS antenna or at least a model number someone may be able to give you an idea of what kind of a gain you could expect with a different type of antenna over what you have now.

I have had installs where people can get stations that thier TVfool plot said were in the -10-20 nm range on a regular basis but they couldn't get others that TVfool claimed were stronger. It's very hard to predict signals traveling over certain terrains not to mention other obstructions.

iScar,
Based on you TVfool plot as 300ohm said your chances are not good but I've seen those plots to be off a bit so lets base your chances on what you actually receive with your current equipment.

How big is that RS antenna, some of those Radio Shack antennas were decent and some were junk. In any case there are antennas available that will out perform most any RS offering. If you could post a picture of your RS antenna or at least a model number someone may be able to give you an idea of what kind of a gain you could expect with a different type of antenna over what you have now.

I have had installs where people can get stations that thier TVfool plot said were in the -10-20 nm range on a regular basis but they couldn't get others that TVfool claimed were stronger. It's very hard to predict signals traveling over certain terrains not to mention other obstructions.Heres a couple pics of the antenna.

http://i903.photobucket.com/albums/ac231/wadevk/4-13-2010/DSC00182.jpg?t=1271192971

http://i903.photobucket.com/albums/ac231/wadevk/4-13-2010/DSC00183.jpg

Its not that old. Its a Radio Shack VU-160XR.
The offical Radio Shack quoted specs are here : http://support.radioshack.com/support_video/doc44/44032.htm
You can see pictures of it here in the 1995 and newer catalogs: http://www.radioshackcatalogs.com/

The gains are quoted in dBd, to get dBi figures add 2.15. The quoted milage range charts are pure fantasy, so ignore them.

As you can see, the UHF dBd gains (while conservative) arent that good. A SBGH outperforms it. I have the corner reflector off of a VU-190 and can confirm that, heh.

VU-120XR and VU-190XR VHF gain charts are here : http://www.hdtvprimer.com/ANTENNAS/comparing.html

Is that analog channel 5 and FM important to you ? I take it that channels 9, 12, 26 are the most viewed ones, and they are pretty strong.

Its not that old. Its a Radio Shack VU-160XR.
The offical Radio Shack quoted specs are here :

The gains are quoted in dBd, to get dBi figures add 2.15. The quoted milage range charts are pure fantasy, so ignore them.

As you can see, the UHF dBd gains (while conservative) arent that good. A SBGH outperforms it. I have the corner reflector off of a VU-190 and can confirm that, heh.

VU-120XR and VU-190XR VHF gain charts are here :

Is that analog channel 5 and FM important to you ? I take it that channels 9, 12, 26 are the most viewed ones, and they are pretty strong.I actually dont even receive channel 5 whatsoever... which is odd to me as its relatively close, but its not important to me at all. 30, 28, 9, 12, 26 and 21 (new channel not listed on TVFool for some reason) are the ones we watch the most. Do you think a newer antenna such as a CM4228 would give better results?

If you dont need channel 5 and FM, then the size of the antenna can be reduced drastically with the same results. (not by cutting the VU-160, but with a smaller designed antenna) Looking at your mounting situation, thats a good thing, heh.

you think a newer antenna such as a CM4228 would give better results?
The one available now is the CM4228HD, which is not as good as the old CM4228a, and Im not sure how well it would do for your channels 9 and 12. UHF wise, it would be as good as the present VU-160 and a heck of a lot smaller.

I take it you rotate the antenna by hand for channel 12. That unlisted channel 21 will decrease the chance of getting that other distant channel 21 drastically.

Personally, I would build a SBGH with NARODs or a M4 bowtie with a 32" wide reflector to take care of your needs in a smaller, less wind load manner.

If you dont need channel 5 and FM, then the size of the antenna can be reduced drastically with the same results. (not by cutting the VU-160, but with a smaller designed antenna) Looking at your mounting situation, thats a good thing, heh.


The one available now is the CM4228HD, which is not as good as the old CM4228a, and Im not sure how well it would do for your channels 9 and 12. UHF wise, it would be as good as the present VU-160 and a heck of a lot smaller.

I take it you rotate the antenna by hand for channel 12. That unlisted channel 21 will decrease the chance of getting that other distant channel 21 drastically.

Personally, I would build a SBGH with NARODs or a M4 bowtie with a 32" wide reflector to take care of your needs in a smaller, less wind load manner.Channel 12 is usually strong enough to come in no matter where the antenna is turned but yes we do turn it by hand to get 21 or 12 on a bad reception day.

Also the unlisted channel 21 is from the same area as 12, since it isnt the same direction as the other distant 21 would it still effect it?

I will have to look into what it takes to build one of those antennas... Thanks for the advice.

since it isnt the same direction as the other distant 21 would it still effect it?
Since they each would be close to the null zone of any antenna, that would improve the chances of getting it.

and boosted the signal on WDAY 21 to 55%
Is that 55% consistant from day to day, or was that just a one time measurement ? And are you sure it wasnt the stronger 21 ?
And whats your signal reading on KVRR 19 ?

(not by cutting the VU-160, but with a smaller designed antenna)
Actually, in your specific case, I take that back. I did a quick chop of Ken Nists model of the VU-120XR, which is very close to the VU-160XR, leaving only 3 pairs of vhf elements and phasing lines that are behind the uhf corner reflector. Net Gain on channels 9 and 12 decreased very little, if at all. (Raw Gain 7.59 dBi on channel 9 with a SWR of 1.48. Raw Gain of 7.24 dBi on channel 12 with a SWR of 1.29 after the chop)

In general though, I dont like to chop up working commercial antennas. If you do chop it, do it so the chop can be easily undone if need be. I would also change the mounting position so the antenna is rebalanced. The benefit of the chop would be less weight and wind resistance.

drewwho: You might be interested in the Ceton InfiniTV 4, a Quad ATSC/QAM Tuner PCI card:
http://www.cetoncorp.com/products.php
Website is accepting pre-orders now for shipments beginning 31May2010.
It also supports a CableCARD for decrypting digital cable channels.....

No, for a number of reasons. I don't run windows, and I'm a cheapskate who likes to get everything OTA and via hulu :) I just wish the HDHR's tuners were better.

Oddly, I'm having better luck getting stations from a neighboring market that are 58 miles away. The signal strength is low (mid 60s), but whatever SNQ is, it is steady at 100%, and I have very few tuning errors.

Drew

Is that 55% consistant from day to day, or was that just a one time measurement ? And are you sure it wasnt the stronger 21 ?
And whats your signal reading on KVRR 19 ?


yes it goes from about 50-56% all the time, We can receive it on very calm clear nights, just not during peak hours or when its windy.

KVRR 19 is about 40% i think, I will check it again more extensively with positioning tomorrow and let you know.

KVRR 19 is about 40% i think, I will check it again more extensively with positioning tomorrow and let you know.
KVRR 19 at -11.4 NM and 75.4 miles should be stronger than WDAY 21 at -16.2 NM and 108.7 miles.
If youre that close to locking on with the uhf part of the VU-160XR, then a higher gain antenna (and more height) may do the trick. If building, I would try a DBGH with NARODs. If you want to buy, then try a Winegard HD 8800 and keep the VU-160XR for vhf-hi.

KVRR 19 at -11.4 NM and 75.4 miles should be stronger than WDAY 21 at -16.2 NM and 108.7 miles.
If youre that close to locking on with the uhf part of the VU-160XR, then a higher gain antenna (and more height) may do the trick. If building, I would try a DBGH with NARODs. If you want to buy, then try a Winegard HD 8800 and keep the VU-160XR for vhf-hi.Just checked again and KVRR fluctuates between 27 and 39 so its not a strong signal... There is a large tree close to the antenna and the antenna is somewhat blocked by it when it is turned for KVRR. So I don't know if that would cause a problem.

Yes, the tree would cause a lot of gain loss. Any chance for a better location for the antenna ?

but whatever SNQ is,
Signal to Noise Quality % ??

Yes, the tree would cause a lot of gain loss. Any chance for a better location for the antenna ?Possibly but we would probably need a freestanding tower from somewhere, so i'm not sure.

Multi-Bay Bowtie 4nec2 Analysis Additions and Revisions:
http://imageevent.com/holl_ands/multibay

1. Hi-VHF 2-Bay & 4-Bay Bowties (NO Reflector): Added Ch2-FM Band performance.
SWR and Raw Gain over the FM Band is very usable, but SWR is much higher on Ch6 and
excessive on Ch2-5....however, YMMV.....

2. Hi-VHF 2-Bay with 56"x72" Flat Reflector (2"Hx4"W) Hi-VHF & Ch2-FM Band - All New.
SWR for Ch2-FM was excessive, except for perhaps the top end of the FM Band,
but if the signal strength is strong enough and the VSWR nulls occur somewhere other
than the end of the coax (and the phase of the moon....)....as usual, YMMV....

3. UHF M4 (9.5x9.0) Flat vs Swept Bowties (under UHF 4-Bay Bowties w Refl.):
Added Ch2-FM Band performance and reran UHF & Hi-VHF results (due to a file
editing error, one whisker was missing). Impact on results was very minor, notable
change was 0.5 dB better above Ch51. Analyzed ALL AWG10 M4, in addition to
AWG8 (elements) & AWG12 (feedline) in mclapp's drawings.

4. UHF mclapp's M4 (9.5x9.0) 4-Bay - NO Refl (under UHF 4-Bay Bowties - if NO Refl.):
Added analysis of Forward Swept Bowties. No improvement in Gain, except above Ch51.

5. UHF Old CM-4228 with RF Combiner Mod (under UHF 8-Bay Bowties w Refl):
Added analysis of using an RF Combiner in a standard Horizontal Stack
configuration, rather than the crossover feedline between the left & right 4-Bays.
Significant Raw Gain improvement for low UHF channels and especially above Ch51....
but Net Gain only improved above Ch51 due to the RF Combiner Mod degrading
SWR on the low UHF channels.

6. Updated Multi-Bay Comparison Charts:
http://imageevent.com/holl_ands/multibay/compare

Is that better than the ones that are found in local stores such as Fry's where I can get several for cheap? The ones are use look like these:

http://www.smarthome.com/7808/75-Ohm-Terminator-20-Pack/p.aspx

Hi,

that's still is not a good price for a 75 Ohm resistor with one of its leads sticking out as the conductor and the other soldered to ground of the f - connector.

A cable stumble boy installer tripped and dumped his tray into the flower bed decades ago and supplied me with all that I would ever need.

The expensive pretty ones might look good enough on the Xmas tree to not cause a huge uproar with the spouse as to the price.

SHF

Hi there:

New to this forum. I need help for an attic/roof antenna. Here is my tvfool link:


With an old rabbit ear, I can pretty much get most local channels except ABC (VHF10). I have to adjust the rabbit ear for individual channels for watchable signal strength though.

I am thinking about getting a CM4228HD on the rooftop (2 story house) and like to get all local channels with good signal strength (coming from two different directions) and without a rotor. It will also be a plus if any channels from NYC can be obtained.

Any suggestion? Thank you very much in advance.

Sorry here is the tvfool file. I was not allowed to post it until 3 posts later.

Here it is.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dcd724a32ac7217

I'd like to get all local channels with good signal strength (coming from two different directions) and without a rotor. It will also be a plus if any channels from NYC can be obtained.

If I lived in your house I'd get three antennas.

A 2 bay UHF aimed at the Hartford antenna farms.
A small high band VHF yagi aimed at New Haven.
Add them together with a UVSJ.
If you have multiple TV sets get an AP 2870 preamp.

Next the third antenna would be an HD7698P aimed at New York. It should have an HDP-269 preamp.

Use an A/B switch at the TV set(s) to watch CT or NY stations.

If I lived in your house I'd get three antennas.

A 2 bay UHF aimed at the Hartford antenna farms.
A small high band VHF yagi aimed at New Haven.
Add them together with a UVSJ.
If you have multiple TV sets get an AP 2870 preamp.

Next the third antenna would be an HD7698P aimed at New York. It should have an HDP-269 preamp.

Use an A/B switch at the TV set(s) to watch CT or NY stations.

I would use a rotator with one antenna and one preamp.

YMMV

Hi there:

New to this forum. I need help for an attic/roof antenna. Here is my tvfool link:


With an old rabbit ear, I can pretty much get most local channels except ABC (VHF10). I have to adjust the rabbit ear for individual channels for watchable signal strength though.

I am thinking about getting a CM4228HD on the rooftop (2 story house) and like to get all local channels with good signal strength (coming from two different directions) and without a rotor. It will also be a plus if any channels from NYC can be obtained.

Any suggestion? Thank you very much in advance.

I have a similar setup with a CM4228HD and get from two directions without a rotor.

I have a similar setup with a CM4228HD and get from two directions without a rotor.

The ability to receive from multiple directions is completely dependent on the individual circumstance. Distances, angles, and relative signal powers and channels all play into the equation.

Generally, reliable reception can only be estimated of the front or primary lobe of any directional antenna (and the 4228 is VERY directional). Any reception from any other direction is going to be highly variable and will likely require hands-on experimentation to see if it might work.

IOW, just because it happens to work in your case does not mean it will work in another that may have completely different parameters.

IOW, just because it happens to work in your case does not mean it will work in another that may have completely different parameters.

Unfortunately that was my case. I have a CM4228HD and tried to pull in a single station 50 miles to the south (aiming south) while relying the backside to get stations to the north at about 15 mile away. The southern station came in fine and the northern stations came in at acceptable levels but the signal quality was poor, probably from mutlipath, and basically unwatchable.

The solution was two antennas joined with a jointenna.

The ability to receive from multiple directions is completely dependent on the individual circumstance. Distances, angles, and relative signal powers and channels all play into the equation.

Generally, reliable reception can only be estimated of the front or primary lobe of any directional antenna (and the 4228 is VERY directional). Any reception from any other direction is going to be highly variable and will likely require hands-on experimentation to see if it might work.

IOW, just because it happens to work in your case does not mean it will work in another that may have completely different parameters.

You're right, there are so many variables that every situation is different. I was just suggesting to try one antenna first without a rotor. Just having an outdoors antenna will be an incredible improvement over rabbit ears he is using now.

These suggestions are great! I might get one (a 4-bay or 422HD) first to try on the rooftop. Then decide what to do.
Thank you all very much!

Hello,

Here is the TvFool link for my home.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dcd72321d4e6ed1

My first choice would be to keep the antenna in the attic. The second option is to mount on the roof. I have an old antenna, but its rusted and the previous owner had the wiring done in the wrong way. Currently a rabbit ear antenna picks lots of channels, but some of those have the square boxes appear in the picture sometimes.

If someone can recommend an antenna, it will be really appreciated. I was leaning for DB4 but would like to hear the opinion from experts here.

You've got three VHF stations (KABC, KTTV, and KCAL) to contend with, and the DB4 is not designed for much sensitivity in that band. You apparently have a clear view to the Mt. Wilson transmitter site, so you should be able to use an RCA ANT751 antenna.

Dave,
Thanks for the quick response. One more question - how would Channel Master 2016 work at my home? Reason I ask is, one of the amazon reviewer is from Los Alamitos which is 5 miles away from my home and he is having great reception with it. So, I am leaning towards it a bit.

One more question - how would Channel Master 2016 work at my home?
I take it youre only looking to get the stations that are due north. The CM 2016 will work fine. Hard to say whether youll have problems in the attic, too many variables. Outdoors is a better option.

I take it youre only looking to get the stations that are due north. The CM 2016 will work fine. Hard to say whether youll have problems in the attic, too many variables. Outdoors is a better option.

Yes, you are right on. I am interested in stations on north.

You're right, there are so many variables that every situation is different. I was just suggesting to try one antenna first without a rotor. Just having an outdoors antenna will be an incredible improvement over rabbit ears he is using now.

I'd like to put in a good word for "attic antenna + outdoor with rotator + Join-Tenna." Here's my reasoning: I tried an attic antenna first and got a few nearby stations to the northeast of my location. Then I called a professional installer and got a big ChannelMaster 4248 with rotator, and was able to pick up other more distant stations I really wanted to the southeast. Then I put in the Join-Tenna and I get all of the stations now without having to rotate -- very handy when I want to record programming from two different directions while I'm away.

Ideally, I could have figured out exactly how to point the CM 4248 in advance and wouldn't have needed the rotator, but since I didn't want to do roof work and didn't want to call the installers back for fine-tuning, it was great to have it up there. I also don't regret trying the attic installation. It could have worked for all my stations, and I wouldn't know until I tried. And even when it wouldn't pick up the distant stations, it gave me a second directional antenna to feed into the Join-Tenna.

(Caveat: I lucked out, in that I didn't have a lot of close-together channels that would have overwhelmed the Join-Tenna's capabilities. Others may not be so lucky.)

Okay, just an update:

I decided to go with Channel Master 3016 over 2016 because this one was available for few bucks more at local Frys. Went over to the roof to remove existing chimeny mounted antenna and found out the previous owner had no grounding done. Not to coax and not to antenna mast. Oh well, off now to figure out the grounding of home and how to route the grounding wire.

And the new antenna is so big, I can't put it in the Attic. :(

I decided to go with Channel Master 3016...

And the new antenna is so big, I can't put it in the Attic. :(

Having elements wide enough to work with the Low-Band is the problem and it's not needed for DTV here.

One of these is a lot easier to manage in an attic:

http://www.solidsignal.com/pview.asp?mc=03&p=HBU22&d=AntennaCraft-HBU22-22-Element-HighBand-VHF-UHF-Outdoor-HDTV-Antenna-%28HBU22%29&c=TV%20Antennas&sku=

Having elements wide enough to work with the Low-Band is the problem and it's not needed for DTV here.



You mean, 3016 would not be good for reception in orange county compared to the ones optimized for channels 7-69? I have mounted the antenna, but still trying to figure out the grounding before I connect it to coax.

You mean, 3016 would not be good for reception in orange county compared to the ones optimized for channels 7-69?

No, he's saying that you could have saved a significant amount of size and weight by getting an antenna designed for ch 7-69 only, that performs comparably to the 3016 for those channels. You would also have been more likely to be able to fit it in your attic. As far as you're concerned, the long elements for ch 2-6 are effectively dead weight and bulk.

As far as you're concerned, the long elements for ch 2-6 are effectively dead weight and bulk.
Yep. You should have stuck to your original plan for the CM2016, unless youre using it for an FM antenna also. Outdoors is much better than indoors.

The AntennaCraft HBU22 listed above is also a good choice.

I posted this yesterday in the Orlando forum, but haven't gotten any responses. WESH (ch 11VHF) is the only VHF channel in the area, so this is becoming a real pain in the butt but here is my issue:

Have a weird issue with antenna/reception. At 7am this morning both WESH feeds went to 0% signal strength. All other channels are fine, but they are UHF. My antenna is a AntennaCraft HDX1000.

So I went and looked at the power injector that came with the HDX1000, no power light. Disconnected the antenna feed and the power light comes back on. So I figured there is either a short or the injector went bad.

Purchased a Winegard 8275 preamp and made all the necessary connections. Turn the power on and the power light is lit. So I assumed the HDX1000 power injector went bad. However, still no signal on WESH feeds??? All other channels are fine. I did notice that I had better signal strength with the HDX1000's power injector over the 8275 (couldn't locate a CM7777).

The HDX1000 is mounted outside with no obstructions and the cable from the preamp is about 20ft in length to the antenna with a grounding block. From the 8275 it goes into a power distribution into 4 leads, 2 directly to a HDHome and 2 to 2 different TVs. I have tried just making a connection from the 8725 to the HDHomerun and directly to a TV. Both don't detect the VHF channel.

I posted this yesterday in the Orlando forum, but haven't gotten any responses. WESH (ch 11VHF) is the only VHF channel in the area, so this is becoming a real pain in the butt but here is my issue:

Have a weird issue with antenna/reception. At 7am this morning both WESH feeds went to 0% signal strength. All other channels are fine, but they are UHF. My antenna is a AntennaCraft HDX1000.

So I went and looked at the power injector that came with the HDX1000, no power light. Disconnected the antenna feed and the power light comes back on. So I figured there is either a short or the injector went bad.

Purchased a Winegard 8725 preamp and made all the necessary connections. Turn the power on and the power light is lit. So I assumed the HDX1000 power injector went bad. However, still no signal on WESH feeds??? All other channels are fine. I did notice that I had better signal strength with the HDX1000's power injector over the 8725 (couldn't locate a CM7777).

The HDX1000 is mounted outside with no obstructions and the cable from the preamp is about 20ft in length to the antenna with a grounding block. From the 8725 it goes into a power distribution into 4 leads, 2 directly to a HDHome and 2 to 2 different TVs. I have tried just making a connection from the 8725 to the HDHomerun and directly to a TV. Both don't detect the VHF channel.

Is that a 8725 or 8275 preamp? Did you remove the internal amplifier on the HDX1000? This may be where the problem was in your signal going away. I would look at a Winegard HD7694P antenna if you have good line-of-sight to your desired stations.

Enniu,

Thanks for your response. Yes, sorry it is a 8275 preamp. I justed corrected my orignal post. I can be a little dyslexic. I did remove the internal amplifer on the HDX1000 and only left the 8275 preamp connected. I never had both connected at any time. I am surprised if something happened to the VHF portion of the antenna as its only 4 months old!

I saw the winegard 7694P but was thinking of their HD8200U as i might move a little further away in a few months.

Enniu,

Thanks for your response. Yes, sorry it is a 8275 preamp. I justed corrected my orignal post. I can be a little dyslexic. I did remove the internal amplifer on the HDX1000 and only left the 8275 preamp connected. I never had both connected at any time. I am surprised if something happened to the VHF portion of the antenna as its only 4 months old!

I saw the winegard 7694P but was thinking of their HD8200U as i might move a little further away in a few months.

You never can have too much antenna, in my opinion. It all depends on your mounting location. I am oriented toward the yagis and have the system shown in post 10719 on P. 358. This is for LA stations from San Diego. Works very well. I also use the 8275 preamp. More info in 10722.

The HD8200U covers all VHF and UHF. Do you really need any coverage below channel 7? This would be a larger antenna because of its low VHF coverage (channels 2-6).

The HD8200U covers all VHF and UHF. Do you really need any coverage below channel 7? This would be a larger antenna because of its low VHF coverage (channels 2-6).

Good point, only have 1 channel on the VHF band ands its 11. Maybe the HD7698P would be better. Width is about half of the HD8200U but would a good fit if I move another 10-15 miles north.

Nice professional looking setup. I wish i could mount mine on the eave like yours.

Do you use dielectric grease on your exterior connections? I had used heat shrinking wraps on my current setup, but if i go with a larger antenna the mounting area is going to be more exposed to the elements.

Thanks for your sugesstions

Good point, only have 1 channel on the VHF band ands its 11. Maybe the HD7698P would be better. Width is about half of the HD8200U but would a good fit if I move another 10-15 miles north.

Nice professional looking setup. I wish i could mount mine on the eave like yours.

Do you use dielectric grease on your exterior connections? I had used heat shrinking wraps on my current setup, but if i go with a larger antenna the mounting area is going to be more exposed to the elements.

Thanks for your sugesstions

Dielectric grease is not a bad idea but I have only used it in the past on ham antennas, never on TV antennas.

I had used heat shrinking wraps on my current setup
Unfortunately, that could also trap moisture inside, making drying out slower.

Is this thread the best place to ask for antenna recommendation?

Is this thread the best place to ask for antenna recommendation?Either here or in your local thread is fine.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9fbe99f7273ae0

Is there another place besides tvfool that I can use for analysis also?

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9fbe99f7273ae0

Is there another place besides tvfool that I can use for analysis also?

TVfool is usually the best. There also is antennaweb.org but it is not so detailed.

You will need a combination UHF and high VHF antenna to get most of your stations. You have a good LOS to most. What do you have for mounting? Attic or outside?

It will be outside. I would like to get as many stations as possible. I don't really understand how that is accomplished since directional antennas are usually recommended.

I don't really understand how that is accomplished since directional antennas are usually recommended.
Your signals in the WWN and EES direction are strong. Is there anything in the other directions thats important ? It doesnt look like it to me. A DIY reflector-less SBGH with NARODs could fill your needs in the 2 main directions that are close to 180 degrees apart without using a rotor.

I have no idea what that is, except DIY - means I gotta build something :) I have no idea what stations or channels exist, which ones are important. I just want an antenna that will give me the best reception and channel selection, reasonably speaking.

Wow. I went to antennaweb.org and adjusting the height above ground level really changes the signal levels and available stations, a lot!

It will be outside. I would like to get as many stations as possible. I don't really understand how that is accomplished since directional antennas are usually recommended.

Can I combine directional and omni-directional?

Can I combine directional and omni-directional?

If you really want the best setup outside and want as many channels as you can get in all directions, you will need a ROTATOR and a good UHF/High VHF antenna like the Winegard 7694P.

Antennas are directional by NOT being omni-directional; that is how they have gain.

I have a picture of what I use for LA stations from San Diego County.

But can I have a directional antenna and also an omnidirectional antenna, and combine them?

Looks like I can get the Winegard 7694P for $50 or so, what about the rotator?

Also, how does a rotator work, do you program it to rotate when your tuner is on certain channels? What about if there are multiple tv's sharing the antenna, each tuner would only get a certain subset of channels at any given time, depending which way the antenna is pointed, right? Can I have multiple directional antennas?

But can I have a directional antenna and also an omnidirectional antenna, and combine them?

Looks like I can get the Winegard 7694P for $50 or so, what about the rotator?

Also, how does a rotator work, do you program it to rotate when your tuner is on certain channels? What about if there are multiple tv's sharing the antenna, each tuner would only get a certain subset of channels at any given time, depending which way the antenna is pointed, right? Can I have multiple directional antennas?

Yes, you could have multiple directional antennas if you are only interested in two directions. Combining antennas would reduce signal strength about 3-4 db (about half power) or you could use a switch if you brought both lead-in coax into the house. The half power is the same as you get when splitting to two TV's.

Two antennas would be less than a rotator and that would be one that you manually set the direction on the controller. I have not seen one that switches according to the channel you are on.

You do have strong signals at your location but it looks like the only Fox station is the only one on VHF?

I don't really even know what UHF and VHF means, so I don't know if Fox is the only VHF. How much do you think a rotator would cost. And how do rotators work? Obviously it rotates the antenna, but what components are involved and how to do you control rotation?

UHF is the "real" channels on the TVFool report above channel 13. VHF is the channels from 2 to 13. High VHF is the channels from 7 to 13. UHF is ultra-high frequency and VHF is very high frequency.

The rotator consists of a motor unit (you can see mine mounted below the lower antenna) and is controlled by a compass display box near your TV. They are usually connected via a separate 4 wire flat cable. Mine is a Yaesu 450XL that I used many years ago for ham antennas. This is much more power than you need for the single Winegard antenna. You can Google rotators to see many choices. Most of your signals are in the same direction so you would not be rotating it very much.

But can I have a directional antenna and also an omnidirectional antenna, and combine them?

Looks like I can get the Winegard 7694P for $50 or so, what about the rotator?



The HD7694P will get all of your local network stations. There are LPTV stations near you that transmit a variety of non-mainstream programs. In most cases you can ignore them.

If you opt for a rotor, simply remember to return it to 291° when you are done watching something in another direction. Don't record stuff from other directions.

Thanks for the clear explanation Ennui.

Will a directional antenna also pick up stations that are in other directions but nearby? I don't think I want to use a rotator. I rather keep it simple. Also, I don't want to have to adjust it as I will have multiple tuners connected. That is why I was asking if I can combine two or more antennas.

Thanks for the clear explanation Ennui.

Will a directional antenna also pick up stations that are in other directions but nearby? I don't think I want to use a rotator. I rather keep it simple. Also, I don't want to have to adjust it as I will have multiple tuners connected. That is why I was asking if I can combine two or more antennas.

If you look at the pattern on Winegard's website, you will see it is not sensitive to the side or back. As I said, this is how you get gain in a directional antenna. Unless the station is very local and/or very strong, you probably won't see it.

I do not see what stations you want to pick up. What do you want that is not in the 290 degree direction?

It looks like for $75 you could get the rotator so if you think you may want to change direction, you can. I very rarely change my direction with my rotator. But all your network stations are in the same direction.

This discussion started with you saying you wanted as many stations as possible. For that, you need a high gain, directional antenna and a rotator.

I do not see what stations you want to pick up. What do you want that is not in the 290 degree direction?

... all your network stations are in the same direction.


All I know is that I see stations in many directions on the TV Fool map, so obviously if I am using a single directional antenna, a lot of them get dropped, right?

All I know is that I see stations in many directions on the TV Fool map, so obviously if I am using a single directional antenna, a lot of them get dropped, right?

That is what a directional antenna does.

You would probably not receive anything below WGOX on the list as shown on your TVFool report.

So how do you pick up the rest of the stations?

So how do you pick up the rest of the stations?

As I said, with a high gain directional antenna and a rotator but you will still not get anything below 0 Nm reliably.

I have no idea what stations or channels exist, which ones are important. I just want an antenna that will give me the best reception and channel selection, reasonably speaking.
From TVFool, you can reasonably expect stations that are in the green and yellow. You can google on the station call letters to see what kind of programming they have. For example, your WAWD-DT in the east is a Tourist Network. WPAN-DT in the east is a paid programming channel, ie Infomercials non-stop. The other one you could get in the east is a low power analog station, normally those are even worse to watch than the Tourist or Infomercial networks, heh.
So, do the channels in the east appeal to you ?

Any way to receive stations from multiple directions without a rotator? I guess I don't understand why I cannot combine a couple of directional antennas with a multi-directional antenna and combine their signals. I understand there is some signal loss, but could I use an amplifier to negate that?

As far as channels that are appealing, no they are not especially, but I am interested in the concept of "how do I get them" as much as "will I watch them"

I understand there is some signal loss, but could I use an amplifier to negate that?
When combining two non identical antennas, pointing in different directions, you could get some horrible losses from each of the antennas.

A preamp only takes care of the losses after the antenna terminals, like from the coax, splitters and from a weak TV tuner amp.

Signals below 0 NM youll generally only get on tropo days, and in the south like Florida they are much more frequent than in the north. A rotor could help there, but during a tropo you may get them anyway, no matter which way the antenna is pointed. Tropos are also nuisances because they can knock out your local channels.

Rotors basically start at $59 and go up from there.

Rotators

Double entry.

Heh, yep, rotator is more correct as to its function. Rotor is the commonly accepted slang. http://en.wikipedia.org/wiki/Rotor

Heh, yep, rotator is more correct as to its function. Rotor is the commonly accepted slang. http://en.wikipedia.org/wiki/Rotor

:) I am "single handedly"?? trying to correct that. I have had a ham license since 1956 and never heard "rotor" used until this forum. If you look at the Wiki article, rotor is not used at all. :)

When combining two non identical antennas, pointing in different directions, you could get some horrible losses from each of the antennas.

A preamp only takes care of the losses after the antenna terminals, like from the coax, splitters and from a weak TV tuner amp.

Signals below 0 NM youll generally only get on tropo days, and in the south like Florida they are much more frequent than in the north. A rotor could help there, but during a tropo you may get them anyway, no matter which way the antenna is pointed. Tropos are also nuisances because they can knock out your local channels.

Rotors basically start at $59 and go up from there.


Still don't really understand. And what in the world is a tropo?

If you look at the Wiki article, rotor is not used at all.

?????? :confused:

Rotor (antenna), an electric motor that rotates an antenna to the direction of transmission or reception

And what in the world is a tropo?

Its a tropospheric event that causes signals to go haywire and go much further distances than normal. Forcasts here : http://www.dxinfocentre.com/tropo.html

?????? :confused:

If you click on it, the article explains further. That is where rotor is not used at all. And, after all, Wiki is user defined. So, I assume some user from this forum :) put that definition in there. And I would never call it "commonly used slang". Try Google.

Google on tv antenna rotor and youll see a lot of rotor usage.

The slang probably springs from the Alliance Tenna-Rotor series, the most popular rotators in the 50's, 60's and 70's. Since I still have one of those, mine is definately a rotor, it says so right on it, heh.

Google on tv antenna rotor and youll see a lot of rotor usage.

The slang probably springs from the Alliance Tenna-Rotor series, the most popular rotators in the 50's, 60's and 70's. Since I still have one of those, mine is definately a rotor, it says so right on it, heh.
The current terminology uses 'rotator'. But like you said, back in the golden age of TV, I grew up setting up TV's and antennas as a kid in my grandfathers TV and appliance business and 'rotor' was the only term I know of that was ever used. I still call it a 'rotor'.

-ML

Can I combine directional and omni-directional?Yes, you can combine them with a splitter/combiner. Sometimes it works; sometimes it doesn't.
Also, how does a rotator work, do you program it to rotate when your tuner is on certain channels? What about if there are multiple tv's sharing the antenna, each tuner would only get a certain subset of channels at any given time, depending which way the antenna is pointed, right? Can I have multiple directional antennas?In theory, it can be done. It would be a very expensive custom system; not ordinarily done.
Will a directional antenna also pick up stations that are in other directions but nearby? I don't think I want to use a rotator. I rather keep it simple. Also, I don't want to have to adjust it as I will have multiple tuners connected. That is why I was asking if I can combine two or more antennas.
A directional antenna will also pickup stations that are in other directions but nearby. Whether it works for you will depend upon the directional characteristics of your antenna and the strength of the various signals. The best quality reception is when the antenna is aimed directly at the station. To give you what you want, it will not be simple.

Some people are lucky if they have two groups of stations that are 180 degrees apart. They can use an antenna without a reflector to pick up strong signals from both directions.
Any way to receive stations from multiple directions without a rotator? I guess I don't understand why I cannot combine a couple of directional antennas with a multi-directional antenna and combine their signals. I understand there is some signal loss, but could I use an amplifier to negate that?

As far as channels that are appealing, no they are not especially, but I am interested in the concept of "how do I get them" as much as "will I watch them"
Still don't really understand.
It's not an easy concept to grasp, and it's not a matter of loss that an amplifier can correct.

When two antennas are combined, both receive many of the same signals. When these signals reach the combining point they don't always arrive at the same instant to combine properly. If one signal (from the same station) arrives at a different time in the RF sine wave cycle than the other, there can be complete addition of the two, partial cancellation of the two, or complete cancellation of the two.

The exception, where combining has a good chance of success is when two identical antennas, aimed at the same azimuth, are combined with equal lengths of coax. Any other case is "iffy," and requires an empirical approach (trial-and-error). To use the technical term, the signals must be in phase.

The usual approach is to combine the signals using filters, like the Channel Master Jointenna, or custom filters (expensive) from Tin Lee in Canada. For example, the filter for Antenna A (a bandpass filter) would accept channel no. 1 and reject all others. The filter for Antenna B (a bandstop filter) would reject channel no. 1 and pass all the rest. This keeps any channel number no. 1 signal picked up by Antenna B from interfering with the channel no. 1 signal picked up by Antenna A at the combining point.

Another way, when a rotator is not wanted, is to use an A/B switch to select different antennas.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9fbe99f7273ae0

After looking at your tvfool report, I don't see any need for multiple antennas. Just put your antenna up, aim it a 290 degrees, and split it for as many sets as you have to get most everything down to FOX WALA.

The current terminology uses 'rotator'.
Yeah, but with current technology term usage, where every thing is abbreviated to the hilt and cut off to the first capital letters and grouped, shortening rotator to rotor is not the worst possible sin, heh.

But unfortunately, shortening seems to be a necessary evil, because typing extra to convey the same thought, reduces a writers willingness to write and a readers willingness to read. Assuming everyone understands the same acronyms.

Norm's Rotor Service.

http://www.rotorservice.com/

Count the number of times he uses the word "rotor" on the website.

Ron