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The Official AVS Antenna and Related Hardware Topic! - Page 5

post #121 of 16104
Quote:


Originally posted by cpanther1
The Voom receiver according to Voom is not allowed to decode but one local market by order of the FCC.

This is just plain wrong. The FCC has no rules or regulations about what an OTA receiver (which is what the Voom receiver works as when watching broadcast signals) is allowed to tune or not to tune. If somebody at Voom is blaming the FCC, they're just trying to stay out of the firing line. They may have designed their receiver to work this way, but it isn't because of any FCC regulations.
post #122 of 16104
Now Voom says my personal antenna is the fault. Not.
post #123 of 16104
Quote:


Originally posted by cpanther1
Now Voom says my personal antenna is the fault. Not.

That's where I'd put the blame.

What's the rated gain of your Xium Air antenna? What does its polar pattern look like? They don't say.

For long-distance, reliable reception of digital signals, you need a high gain, highly directional antenna with a high front-to-back ratio. The Xium Air has none of these.

The fact that you get anything with it is more of a miracle to me than anything else.
post #124 of 16104
cpanther 1,
My advice to you is to get another antenna. For UHF the CM 4228 is a solid performer up to about 60 miles. Antennasdirect DB8 is a similar design and they have many other quality antennas on their website but they are a little more expensive. If you need VHF, look at Antennacraft. The low VHF will require a huge antenna for long distance, but the Y10 7-13 is excellent in the high band (7-13) and it's size is very manageable. You just can't go against the laws of physics and the usual rule applies that if it seems "to good to be true", it likely is.

VOOM is typically very responsive to their customers in regards to providing adequate OTA reception. They have provided others here with bigger/better antennas when necessary at no cost. See if they'd be willing to do the same for you.

Charles
Edit: I just noticed that earlier you'd said you bought a CM3020. That's a huge antenna, but it should also be a huge improvement. The reason it's huge if for the low vhf. If your cable run is significant, say 50 ft or more, consider a preamp esp. for UHF frequencies.
post #125 of 16104
Both of my daughters are home this Friday and Saturday. They will help me get the large antenna that I have had for 8 years and move it over to my other mount and check it.

I received good analog signals in a 360 degree range with the Xium so it must not be good with 360 degree reception of Digital signals.

PS. I have a Channel Master digital rotor control programmable remote so that will not be so bad.
post #126 of 16104
Quote:


Originally posted by cpanther1

I received good analog signals in a 360 degree range with the Xium so it must not be good with 360 degree reception of Digital signals.

It depends on what a "good analog" signal looks like to you. If your UHF reception from similar distances and locations is relatively snow and ghost-free, then the odds are that the receiver isn't very good. (As a matter of fact, the Voom is a known dog of a performer for OTA reception.) If you have minor ghosting, that can be more than enough to kill digital reception with a poorly designed receiver. Any strong ghosts or enough snow to make reading text difficult is enough to knock out digital reception.

Omnidirectional antennas do absolutely nothing to reduce multipath (ghosts) and thus are usually inadequate for digital reception.
post #127 of 16104
This may be a stupid question with an obvious answer, but I'm going to ask anyway:

If I had an antenna connected to its preamp by a 12 foot cable of any given type (in particular, twin lead or RG6 coax), would there be a significant improvement in performance if I replaced that with a 3 foot cable of the same type?

I ask because in my situation, such a change would require quite a bit of work (and money) but if it would yeild a major increase in performance it could be done.
post #128 of 16104
Quote:


Originally posted by Electrode1
This may be a stupid question with an obvious answer, but I'm going to ask anyway:

If I had an antenna connected to its preamp by a 12 foot cable of any given type (in particular, twin lead or RG6 coax), would there be a significant improvement in performance if I replaced that with a 3 foot cable of the same type?

I ask because in my situation, such a change would require quite a bit of work (and money) but if it would yeild a major increase in performance it could be done.

It's very doubtful that shortening the cable from 12' to 3' would make any difference.
post #129 of 16104
Electrode1,
Shortening the cable between the antenna and the preamp is always a good idea. However, the amount of improvement you'll see is difficult to predict. You should see more improvement on higher frequencies and less at lower ones (i.e. vhf) as attenuation in the line will increase with frequency. If you're borderline on a channel in the high uhf range, it might be worth it but the only way to know would be to try. Dxers say to couple the antenna directly to the preamp. I've never been sure quite how they do that.

Twinlead has less problems with attenuation but more with interference and stray signal pickup. You're supposed to twist it over a long run I think to maximize its performance. I saw a twist-per-distance reccomendation somewhere but can't remember. Maybe someone else who uses it can help.

Charles
post #130 of 16104
Perhaps I'll stick with my current cable arrangement for now.

On a completely unrelated note, I've been thinking of taking down my "local" antenna and replacing it with something that will provide more VHF gain (I'm not so concerned about UHF, I use a CM 4228 for that). One possibility that really caught my attention is the Magnavox MANT-902. The manufacturer claims it has a 100 mile range, and Spectravox sells it for $32. Does anyone have any experience with this antenna?
post #131 of 16104
Electrode1,
That looks like a knock-off CM3020. The front part is for UHF which you said you don't need and the reason it's about 7 feet wide is for the low vhf band
(2-6). If you only need the high band, a real good option is an Antennacraft or Winegard high band VHF antenna (7-13). It's size is much more manageable and it actually outperforms those monster combo antennas on those channels. There are also dedicated wide band vhf antennas available from Winegard and Jerrold as well as cut channel versions from the same. The lower the channel, the bigger the antenna.
Charles
post #132 of 16104
Actually, low band VHF is quite important. There is a local channel 2 that is quite hard to pull in, and there are numerous 4's, 5's and 6's across the lake.
post #133 of 16104
http://www.starkelectronic.com/del937.htm
If it's low-band VHF you want, then few can beat the power of the VU-937. It has solid gain on all bands, even without the VU-8PZ addon.
post #134 of 16104
I get signal strength of 60-65 on my local CBS, but the sound keeps dropping out while the picture remains strong with no pixilation. I have to go down to below 30 before picture drops out. I monitor the signal strength during drop outs and it remains in the 60-65 range. None of my other locals are doing this. Can somebody help me explain and suggest what to do ? Thanks
post #135 of 16104
Electrode1,
You'll need to go with a wide band VHF only antenna then. Jerrold makes two sizes and I believe Winegard does also. Here's the Jerrold:http://www.starkelectronic.com/delhi.htm
There are two sizes. They are both big.

Charles
post #136 of 16104
The Jerrold VIP-307SR looks interesting, albeit a little expensive. I suppose I have to spend some cash to get decent equipment.
post #137 of 16104
How big is the shipping carton on a ChannelMaster 4228 antenna? Just wondering if I can get it through an attic hatch. . . . (long story)

Doug
post #138 of 16104
It's shipped in one piece and the carton is just slightly larger than the antenna. It is possible to disassemble it if needed but it's not easy. Part of it is riveted together so you have to replace the rivets with nuts/bolts when you put it back together.
Charles
post #139 of 16104
I have Voom and something strange.

On OTA I can only receive one local market( farther than the market closest to me.)

Does anyone else have Voom and receive more than one OTA market area?


Phone Rep 1. FCC prohibits more than one local area.

Phone Rep 2. I should be able to view all Stations my antenna receives.

Question online. The same as phone Rep 1.

Voom installer. The Channel decoding should come in a nightly download from Voom. I should let them know of all the Stations I can receive.

I sent a message to the FCC last Tuesday. I have not yet received a reply.
post #140 of 16104
I am planning to purchase the Antennasdirect DB8 soon (or equivalent). These are UHF antennas. I am located in Shelton, CT (06484) and I have to be able to receive Channels 10 (very strong signal in my area) and Channel 12 . I have been told by someone that these antennas should be able to pick up these VHF (high) frequencies despite it being a UHF antenna.

Does anyone have any experience in using a UHF antenna to pick up (high) VHF digital signals?

Also, would anyone suggest a different brand of equivalent antenna over Antennasdirect DB8?

Thanks

ChuckA
post #141 of 16104
Should be fine. Using a Channel Master 4228 (very similar to antennasdirect DB8), I can pick up channels 7 and 11 almost as well as with a VHF/UHF/FM antenna. 7 is about 30 miles away, 11 is about 10 miles away.
post #142 of 16104
Electrode1

Are you using a pre amplifier. I am planning on using the CM 7777. Should I have both the UHF and VHF linked or should I have it set to UHF only when using only one UHF antenna?

ChuckA
post #143 of 16104
Chucka,
You should hook your antenna to the "UHF/combined" input and be sure the switch internally is on "combined". Otherwise, you won't get any VHF channels.

Charles
post #144 of 16104
I have a Radio Shack VU-90XR 26 Elements outside antenna (Covers Yellow to Green Areas, no pre-amp) . I get the 3 local stations with PBS and Univision crystal clear. I wanted to add FOX and PAX. According to Atenna Web I should be able to add up to 6 more staions via UHF.

So, I bought a Philips/Magnavox MANT902 36 Elements Outdoor Antenna that is supposed to cover Yellow thru Violet Areas, no pre-amp. I installed it and tried it out and all my channels (even the ones that were clear w/ the other antenna) turned out really snowy and unclear. As far as hook up, I left the cables and everything else alone and just replaced the antenna on the mast.

Can anyone tell me if I did anything wrong? Or why a more powerful antenna would get a weaker signal than the smaller one?

Zip code: 78418
Street: Meadow Ridge
City/State: Corpus Christi, TX
Terrain: Flat


__________________
post #145 of 16104
bsr2002,
There are several possibilities. Assuming the specs for these two antennas are correct you should expect at least equal or most likely better performance from the larger one. One possibility would be that conditions changed during the time you tried the larger one. This happens constantly and is very frustrating when trying to compare different setups for performance. Also, check the aim of the antenna and be sure it's aimed properly. Higher gain antennas often have narrower beamwidths which makes aiming more critical. Check to see that the height of installation hasn't changed. Finally, check the balun which came with the second antenna. Try the balun from the first and make sure that's not the difference.

Charles
post #146 of 16104
Quote:


Originally posted by bsr2002

So, I bought a Philips/Magnavox MANT902 36 Elements Outdoor Antenna that is supposed to cover Yellow thru Violet Areas, no pre-amp. I installed it and tried it out and all my channels (even the ones that were clear w/ the other antenna) turned out really snowy and unclear.

There is no way the Philips is good to Violet. The UHF section is a joke. Look in this thread and forum for many highly recommended UHF antennas.
post #147 of 16104
Quote:


Originally posted by giantcycle
How big is the shipping carton on a ChannelMaster 4228 antenna? Just wondering if I can get it through an attic hatch. . . . (long story)

Doug

as CPCAT said- the 4228 can be basically broken in half- just drill out the rivets on the bars that connect the 2 halves together and then once you are in the attic replace the rivets with nuts and bolts.

BUT if you are within 30 (or maybe even 50) miles of your towers and they have decent power levels I would go to the sears (others have found it at circuit city) and pick up a silver sensor and try that first. If it doesn't work then return it and try the 4228.

I'm actually surprised no one has seriously mentioned the silver sensor in this thread before other than one mention of an 'inside antenna'

I got the 4228 and drilled out the rivets and wrestled the 2 halves through the hatch then put it all together back in the attic. Got it to work pretty well but then i wanted to try getting some stations from another direction and didn't want to wait a week to get another 4228 in the mail so a picked up a silver sensor at the local sears. I actually walked past the thing 5 times looking for it because it is so darn small, i couldn't imagine that it would work. Got it home and surprise surprise it works bascially as well as the 4228 for getting Philadelphia at about 30 miles and for getting the high powered stations out of NYC at about 50 miles. The 4228 can get one more of the mediumish stations out of NYC but thats it. Shortly NYC stations should be competing a combiner project and I suspect the silver sensor will get all the stations that the 4228 does at that point.


I was very pleasantly surprised. And for something that is such trial and error buying something in person i can return is alot better then having to wait a few days to get the parts for 'plan B'. Also theres no need to figure out a mast in the attic to mount the silver sensor- it basically has a base on it like you would place it on top of your book shelf or something- so i threw up a piece of scrap wood for a shelve instead of having to make the 2 trips to the Home Depot and rat shack to get all the parts i needed to make the mast for the 4228.

Above results in my attic with a CM 7777 pre amp running probably 60-70 feet of cable to a terk 5x8 multiswitch. From there anther 15-20 feet to a diplexor and then into a HD directivo.

(also for more info- i am totally anal so i first connected the hdtivo to about 20 foot of cable and connected that directly through the attic hatch to the preamp on the antenna. I wrote down all the results and then checked again after adding each component and length of wire and basically got the same numbers GIVE or take 2-3 points on the signal strength meter)
post #148 of 16104
i'm looking for some knowledge on combining 2 antenna's. If you see my post above once NYC gets its act together with the combiner, I should be able to get pretty much everything from Philly -OR- NYC on a single antenna just fine. But I would like to get both- having a tivo i cant predict which way to aim and might even need both directions at the same time - a rotator isnt really an option so I need to combine 2 antenna's. I'm hoping someone has a little insight before i try 110 trial and error steps.

A pile of questions.....

I'm not really in a situation to combine a 2nd antenna for just one channel like the jointenna's do rather I need to wholesale combine like 8-10 channels from one antenna with 8-10 from another. I've read and/or posted to the NYC thread, the Philly thread, and the central NJ thread but haven't gotten much luck yet- although have gotten some replies that make me think its very possible- but no one has tried to get all the possible channels to work at once and it doenst seem impossible to me from a technical perspective. I pass my local cable office occasionally and they have all kinds of antennas aon a tower that look like plain old radio shcak specials aiming all over the place- they must combine then somehow?


I do have an issue with an analog channel from NYC killing a digital from Philly so i almost definately need to get a notch filter for channel 31. Once idea i had was to get a jointenna to add channel 31 to the NYC feed- but just don't add it so that 31 would get stripped from the NYC antenna and then combine after the jointenna. I'm also wondering if in a perfect world would it be best to get a bunch of notches and just kill off the unneeded frequencies on each cable before the diplexor. But looking around i cant seem to find any easy way to do that- the jointennas really don't seem well suited to such a plan. I searched and searched and found this site that says i can basically cut a length of cable that dead ends to a tee to kill off unneeded frequencies- i was thinking of maybe adding a 5 way splitter and using the 3 unused tees to kill off the 3 channels that would be best to kill. Is that necessary or overkill? http://www.homewiringandmore.com/int...utions.html#20
Searching around I find a few references to kits used to steal cable tv where you can built your own notch filters to kill certain blocking signals for like $15 and I would do that but it seems the kits only work up to channel 22 and since i'm all over the UHF band that wouldn't help me much- got an email into the people that make the 'educational kits' to see if they have different parts for killing off UHF in the spaces between 22 and 69.

I am also a little confused about the whole same length cable issue. Seems the mantra is to make sure both antennas have the same length cable before the combiner but then then i read that was only relevant for multipath- however i think i am in pretty much perfect luck to that since my antennas aim almost opposite directions but not quite180 and i can use the aluminum siding from the side of the attic to block the rear's so each antenna really only will pick up where it is aimed. I tried combining but didn't exactly get stellar results- i tried with with same length cables and without- so not sure if thats an issue. And for the record what exactly is "same length" can i trust 2 '3 foot cables' from rat shack or does an extra milimeter that wasnt clipped oft he center conductor on one cable going to ruin the whole thing. Also the only way I can think to really get teh exact same lenght is to have 2 indentical antenna's - where do i measure from on a CM4228 versus the silver senor for example- or do I need to just get 2 of the SS's or 4228's? Any thoughts about the whole same length issue? What happens if i start adding in nothc filters- how to a calculate lengths?

Next I thought the combiner i use might be an issue- i first tried it with a splitter that Bellatlantic used on my Brother in Laws house years ago when they installed Directv to split the OTA analog antenna so I thought that would be high quality (long story there) . But then I read a splitter isn't exactly the same as a splitter/combiner. So I picked one up a radio shack that says 'splitter/combiner' and plan to use that- maybe i'll get better results. Any idea what to look for there- radio shack has like 4-5 choices so i just got the most expensive. Then I see at werner electronics that cm makes a combiner- do I need that? I've read that by combing the 2 antennas I will wind up transmitting some of the philly power out of the NYC antenna and vice-versa. Is there something like a diode that you can put in the combiner to stop the signal from backtracking up the other leg?

I'm just fiddling around now- an hour or 2 here and there but once NYC gets the combiner done and I have lots of choices in both directions i hope to be able to figure this all out.

I've searched around here and all over the web and theres lots of info about combining 2 or more antennas to get one source but i can find anything really except join-tennas to get 2 different sources. Not afriad to read so if you have links fire away

THANKS
Mike
post #149 of 16104
Michaelk,
Have you tried taking the screen off of a CM4228 to see how many you can get all at once through one antenna? If you could get most with one antenna, it would greatly simplify things for you and maybe you could go the mast filter route for the ones you lack. Also, VHF and UHF channels are easily separable and there's no problem in using antennas in different directions there. In addition to the jointenna product, also look athttp://www.triax.dk/ifs/files/triax/..._Combiners.jsp
Triax makes just about anything you'd need I think. It's just a matter of figuring it all out and deciding the best way to do it. A potentially difficult problem will arise if you try to separate channels that are very close, say only one or two numbers different.

Cable lengths are only important if you are stacking antennas i.e. combining identical antennas for more gain, directivity, etc. pointing in the same direction. The multipath is so bad with dissimilar antennas in different directions that cable length is the least of your worries. That's why the filters have to be used. In other words, you can't get the same station on two different antennas or it will corrupt the signal with multipath.
You'll have to figure out a complicated filtering scheme if you have multiple channels scattered up and down in frequency on more than one antenna.

My understanding of how the Cable Co.'s do this is with single-channel antennas with channel-specific amplifiers and filters.

Good Luck
Charles
post #150 of 16104
Quote:
Originally posted by cpcat
Michaelk,
Have you tried taking the screen off of a CM4228 to see how many you can get all at once through one antenna? If you could get most with one antenna, it would greatly simplify things for you and maybe you could go the mast filter route for the ones you lack. Also, VHF and UHF channels are easily separable and there's no problem in using antennas in different directions there. In addition to the jointenna product, also look athttp://www.triax.dk/ifs/files/triax/..._Combiners.jsp
Triax makes just about anything you'd need I think. It's just a matter of figuring it all out and deciding the best way to do it. A potentially difficult problem will arise if you try to separate channels that are very close, say only one or two numbers different.

Cable lengths are only important if you are stacking antennas i.e. combining identical antennas for more gain, directivity, etc. pointing in the same direction. The multipath is so bad with dissimilar antennas in different directions that cable length is the least of your worries. That's why the filters have to be used. In other words, you can't get the same station on two different antennas or it will corrupt the signal with multipath.
You'll have to figure out a complicated filtering scheme if you have multiple channels scattered up and down in frequency on more than one antenna.

My understanding of how the Cable Co.'s do this is with single-channel antennas with channel-specific amplifiers and filters.

Good Luck
Charles

great idea to pull the screen- there is a spot wher ei can position the 4228 and get a little something off the back, so maybe just pulling the screen is all i need.

THanks for the link- looks like a great source.

if i get it all to work, i'll be sure to report back.

Mike
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