The Official AVS Antenna and Related Hardware Topic! - Page 491

I would only put up an outside antenna if you want to receive that ABC station.

The potential preamp overload problem can be solved by using a Winegard HDP269 and a distribution amp in the house.

That ABC station complicates the antenna situation. If you put up a good combo antenna like the Winegard HD7698P, then you may have trouble with your UHF stations if you point at 16 degrees. That's quite a ways off from 68 degrees especially on UHF. You may need a rotor.

If you're willing to go with separate VHF and UHF antennas you could point the UHF antenna at 68 degrees and then use a lower gain VHF antenna like the Antennacraft Y5713 and point it at about 30 degrees. The main lobe is very broad and there would be almost no gain loss just 14 degrees off pointed.

All this depends on just how weak that ABC station actually is.

Chuck

UPDATE - I purchased two heavilly discounted open box antennas for my experiment:

Antennas Direct ClearStream1 and DB8

I was surprised to find how well indoor reception was with the ClearStream1. Overall indoor reception of the weakest locals improved from about 75% for a "perfectly positioned" RCA 1050 wing to 85% with the Clearstream1 at most room locations. Very satisfactory except for its bulkiness It certainly was a great improvement over every other indoor antenna I have fiddled (Mohu Leaf, RCA 1050 wing, unk. rabbit ears). I would even consider the larger ClearStream2 indoors if it wasn't for our goal to get these indoor antennas out of way.

Next experiment was to move the Clearstream1 outdoors mounted on the satellite dish pole about 6 feet above ground. Again, reception improved notably. (And it looks good outdoors, like modern garden art .) The couple of locals that are the weakest improved from about 85% to 95%. One analog station is finally watchable but simply can't compete with digital TV quality.

OK, with these results I was very curious to know what more distant stations I could receive while pointing the ClearStream1 in different directions at ground level. To my surprise I was able to pick up a station roughly 180° opposite from my locals and 44 miles away (WWRS) at about 40% with my locals still coming in and watchable through the backside. Now my curiosity was stoked! What more could I receive with a larger antenna at a greater height? Now that I knew it was possible to receive WWRS at my location I wanted to receive everything possible with a permanent antenna. Having the opportunity to experiment was something I couldn't resist. So enter the DB8.

The DB8, like most high gain antenna, are very directional. They receive best from one direction. What I needed was a bi-directional antenna, one that would receive primarily in two directions (fore and aft) simultaneously. My scheme was to mount the DB8 without the rear reflector screens which is what makes it a one direction or uni-direction antenna. Removing the reflector screens would make it essentially bi-directional. Think a figure eight "8" reception pattern. Albeit, with less gain from either of two directions compared to with the reflectors in place and reception in one direction. A compromise I was willing to accept IF I could mount this contraption out of site and as high as I could without offending the neighborhood.

In a nutshell, what I did was use 1x3 cedar batter boards ($1.79/6ft) to replace the horizontal aluminum cross braces that would normally be used to mount the DB8 with reflectors to a mast. I pre-drilled all holes using the replaced horizontal aluminum cross braces as a template to maintain spacing and to avoid splitting the brittle cedar wood. Using the original bolts and spacers I bolted the two vertical 4 bow-tie elements to the 1x3 batter boards. I then climbed up into the attic and mounted it onto a vertical 2x4 roof strut near the roof peak with two wood wedges. The wedges are used to orient the antenna with a 10° offset from 90° East and 270° West (I.E. 80°E & 260°W). I connected the RG6 coax cable (Belden 1694A with Canare connectors) to the included antenna bal-un and fed it to a 3-way splitter in the basement.

Conclusion - I had a lot of fun! I receive all my locals consistantly at 100% with a dry asphalt roof at all three televisions. The distant station (WWRS) comes in at about 55% and is perfectly watchable. What penalty I will pay when it rains or the snow accumulates remains to be seen. The only small, but not surprising, disappointment was no other distant stations were found. But I now have very good reception with a very good invisable antenna. The ClearStream1 remains mounted at the dish as back-up in case rain or snow becomes a problem. Besides, it looks kewl

Thanks to those who gave advice and who took the time to PM. Good viewing to all!

The Clearstream 1 makes a very good indoor antenna, not only for UHF, but in my case, VHF as well. I get strong signals for UHF channels at 75 miles. And even the Clearstream 2 can be used indoors as well. And for fringe reception, the CS4 is very good, especially if a more compact size is needed instead of a DB8 or 4228.

I'll add that the Antennas Direct C5 can be an excellent solution for suburban to in-city locations where there are a lot of strong UHFs and a couple of VHFs that require moderate gain to receive. At UHF, the C5 is a pseudo-omni with negative gain. However, when you've got multiple signals with predicted noise margins of 40+, you don't need gain!

A neighbor put up two Clearstream antennas that he found for sale on Craig's List... a C2 and C5 combination... and he's very pleased with the results. He is receiving all stations within 35 miles of here and they're coming in from several different directions from NW, West, South, Southeast and East.

Larry
SF

Since mast-mounted preamps can be damaged by surges, which of the recommended devices in holl_ands quote should be installed before the preamp?

Thank you

Those are normally used after the preamp, before the coax goes into the house. Ive never seen one used before the preamp, but I suppose if the mast is thick and grounded, it could be done.
Keep in mind, with a direct lightning hit, the preamp would be toast anyway.



Re: Enclosure for balun.
In retrospec, the plastic easter egg shell may only last a couple years outdoors. (although some plastic things that don't need to be UV resistant are surprisingly UV resistant)
A more permanent enclosure would be to use one of the grey plastic electrical boxes, sealed at the top with weep holes at the bottom.

Maybe not so much. Modern preamps have built-in surge protection circuitry.

Winegard: "Specialized circuitry featuring fast recovery diode that protects against lightning-caused pulses. "

Tinlee: "Static discharge provided"

Channel Master: "Full lightning and surge protection"

A couple years ago I had a nearby lightning strike that took out the anemometer on my Davis weather station and two ports on a wired router but my preamps were unaffected.

Of course a direct lightning strike will take out the preamps and maybe even the antennas.

Two out of three of the holl_ands links are broken.

Chuck

I've found that 2 liter soda bottles (#1 plastic) are essentially UV proof. I used one to cover up a 1.7 GHz dish feed from water because it was almost RF transparent and it turned out to be UV proof as well. No degradation after 5 years of sun exposure. I would think that the green colored bottles would make good UV filters although I have no way to measure the spectral transmission of them. I'm currently using 3 of them to cover up antenna feeds that don't like getting wet. They are easily cut to fit whatever is necessary.

Chuck

True. And even nearby hits can take out a preamp. The lightning can hit a tree or other nearby object, get into the ground system and fry the preamp or other equipment via that path. You never know what lightning is going to do!

Links repaired.

I live in southeast texas. Very hot summers and lots of rain (ok, ok, we did have a dought last year...), but my point is, we usually have 4-5 months of temps well above 90° (the majority above 95° and several days above 100°) along with lots and lots of rain during the year.

My solution to the mix of rain and heat is to stuff the f connector with a good quality dielectric grease to keep the moisture out and then cover the antenna balun with a rubber boot and then wrap the heck out of it with electrical tape which serves not only as an added protection for moisture but also protects the balun from direct sunlight. I also do the same thing for any connections on preamps. The dielectric grease is instrmental to keeping moisture out of the connection.

All I will say is that this has worked well for me. My last installation at my house has been in place since 2007 after I lost my previous rig to Hurricane Ike. Still going strong...

I purchased a "still new in box" previous model "Tivo HD" model # TCD652160 on-line. It arrived yesterday and the difference was amazing. I know one can not compare signal strength meters between models, but it was as much as 15 points higher on the Tivo HD model as the Premiere. Most importantly SNR's that had constantly fluctuated between 20 and 30 were quietly holding at 30 or 31. Absolutly no problems with picture break-up or drop-outs.
It is a shame to have to go to so much trouble and purchase a previous model to solve this problem, but it will work for me. I am primarily a "time-shifter" and I believe this unit will serve my needs nicely.

You are correct. The last Tivo with a good OTA tumer was the TivoHD. I've had mine for 3 years now, and it performs very well. Even for TV DXing.

Looking for a nice antenna to pick up ABC, NBC, FOX, CBS in my area and distribute to 4 tvs. Here is a link to my results. I've never played with antennas at all so I am walking into this completely blind. I need all the help I can get.

I would prefer to have a small antenna that I could mount in the attic if possible. Any help you can offer is GREATLY appreciated.

URL is :
www . tvfool . com/?option=com_wrapper&Itemid=29&q=id%3d3616f0d649ec27

http://www.tvfool.com/?option=com_wr...3616f0d649ec27

Attic results are difficult to predict, due to building materials that can affect reception.

Ideally, you need a bidirectional wide beam uhf/vhf-hi antenna. There are no commercial antennas of that type. However, you can build your own.
This GH0n3 should suit your needs:
http://clients.teksavvy.com/~nickm/g..._8V5_12u1.html

Point it South West.

Our V10 is pretty close to that. Our C2v with the reflector removed certainly is. Both are relatively short-medium under this scenario range.

Almost any panel antenna can have its reflector removed to make the UHF reception bidirectional. Adding a simple VHF dipole will make a simple VHF bi-directional antenna.

Links repaired & model #s added:

Understood. If one were to add surge protection before the preamp, which of holl_ands recommended device(s) would be best suited for this location? Agreed, with a direct hit, all bets are off.


Sounds great - Thank you.

Agreed, the major preamp brands do offer some degree of surge protection. But they do not provide detailed descriptions with specs for the surge protection.

Also, there are a few brands of ultra-low nosie amps (ULNA) that have little or no surge protection in order to achieve ultra low-noise levels.

Re Over-voltage Surge Protection:

I fixed the two missing links in my original Oct 2006 post:
http://www.avsforum.com/avs-vb/showthread.php?p=8591196
they are replaced by:
http://www.nottltd.com/lightning.html [NOTE STATIC DISSIPATION DEVICES.]
http://en.wikipedia.org/wiki/Varistor
http://www.teal.com/newsletter/AppsNote11.pdf
I also added the following, additional overview:
http://www.lightningman.com.au/surge_technologies.html

The protected voltage range is very high for most of these devices, providing minimal
benefit on the input of a Preamp. The only device with a fairly low protected voltage
range is the Holland SA-1F SiDACtor...and similar devices...but NOT MOV's since they
slowly degrade over time.

It might help to ALSO ensure that there is a LEAKAGE path from the antenna's
active element(s) to the nearest ground (e.g. mast, coax shield or ground wire).
This could be as simple as 10 K-ohm, 1W resistor(s) connected to balun feedpoint(s),
with a short wire to a nearby ground point. This will drain away static electricity....

Nearby Static Dissipation Devices (see new link above) might also be of interest....

Maybe we need a little perspective on this. No manufacturer is going to put expensive multiple levels of surge protection into a device that sells in the range of $40. Even expensive preamps are mostly under $100. Some protection is better than none. I'm sure some preamps get zapped every year but most people will never have that experience. If the cost to insure is high compared to the value of what is being insured, then don't insure.

I've gone to a lot of trouble to get the lowest system noise figure possible and I'm not going to add devices that degrade that even 1 dB. I'll replace the preamps if they get zapped.

Chuck

Clear Cast Indoor Antenna ? ?

The other day, there was a full page add in the Dallas Morning News for the Clear Cast indoor antenna. $47.00.

Does anyone have one ?

Are they any good ? ?

The add seemed to prey upon the gullible in that the add emphasized 935 free shows a year. And they gave a list of zip codes that were eligible ----- OTA digital TV is available to most zip codes anyway !!!

The add is selling itself as a "magic box" that you you use instead of cable or satellite to get all these "free channels".

But really, all it is, is an antenna. For $47....

So is it any better or worse than anything else out there ???

You mean this one ?

http://stopthecap.com/2011/12/19/hyp...bills-forever/

http://cameradigitalprinter.com/clea...al-x1-antenna/


Heh, yeah, SHOWS, not channels. So if you get 30 digital channels, and each channel has say 20 shows over a 24 hour period, that's 600 shows per day. So figure half the shows get cancelled in mid-season, so 900 or so shows a year isn't a terrible estimate.

Full page ads do cost a lot of money though.

Since there are no gain specs posted I can find, that says a lot.

That's a lot of marketing hype for a basic bow tie antenna placed inside a thin layer of plastic that can be hung from a window. The basic Radioshack version should work just as well. And the best performing flat panel antenna reportedly is the Mohu Leaf, which can also be hung from a window for about the same price as the Clear Cast.

I remember the same marketing hype back in the analog TV days where it was claimed the wiring in your house could be used to give you crystal clear ghost free TV reception. Just plug this device into the power outlet and hook it up to your TV. Inside was just a small capacitor soldered inside.

BTW a very recent review says the amplified Mohu Leaf is even better.

I think I saw that magic antenna in the fairytale land portion of Once Upon a Time.

I saw the ad in Parade today.  It lists out, state by state, every two-digit zip code prefix whose residents qualified for the offer.  Of course, it includes all fifty states and DC, and every two-digit zip code prefix in use in that state.  Yet they expect readers to be so gullible that when they find their state and the first two digits of their zip they'll consider themselves lucky to be eligible for an unbelievable opportunity.

Thanks for all the links. They should keep me busy. (Note this one link: http://www.nottltd.com/article.html doesn't work.)

Thanks also for the Holland SA-1F and 10 K-ohm, 1W resistor recommendations. Sounds like a plan!