The Official AVS Antenna and Related Hardware Topic! - Page 478

http://www.tvfool.com/?option=com_wr...7fb9d3267a88bb I need to know how I can hook up 2 Antennas I want all the Channels in the green but also Want WUND 2 out of NC with out rotating my antenna everytime , I had a neighbor accross the street who has 2 ota Ant pointing in oppisite directions wondering if they make a Antenna signal combiner to bring the signal into on cable...thanks

Can you get WUND at all with 1 antenna? It is about 68 miles away with 2 edge reception. Might be a challenge.
Do you know if your neighbor was able to get the channel?

yes I pull it in at 85 % , but I have to rotate my ant.. when I point toward norfolk.. also WSKY 4 fades in and out.. so I was hoping by pointing a second antenna would fix this

What sort of antenna are you now using?

Combining two antennas pointing in different directions will subtract gain from both.
For reliable reception of WUND, youll want to have 2 antennas with 2 coax downleads into an A-B switch at the TV. Cheaper and faster than a rotor.

Try a channel 20 Jointenna.
http://www.warrenelectronics.com/Ant...Jointennas.htm

thanks for the help

http://www.tvfool.com/?option=com_wr...67d9c2f4775255

so are the 4 bay bowties out of vogue now? I was going to put on in the attic.

You have two VHF-HI channels (NBC & FOX). The 4bay bowties are mainly for UHF. They will sometimes work for VHF-HI, but usually the signals must be fairly strong.

Also, attic or other indoor reception of VHF channels is sometimes much more difficult than UHF, because UHF penetrates building materials more easily. In your attic, I would get an antenna designed for both VHF & UHF.

If you stick a wide reflector (36" wide is good, anything over 28" may be fine too) on your 4 bay bowtie, you should get 9 and 11. If you dont, then youll need a more powerful vhf-hi antenna.
For an attic, you could use a piece of cardboard or plywood with aluminum foil. Or even better, after looking over your speaker build, if you have some of that thermax sheathing left over, it will do.

If you have any thermax (foil) in the attic, your antenna may not work well at all up there.

Thanks to the help pasted in below - I was able to get all stations first try - no adjustments or anything. Thanks again!!!

Originally Posted by arxaw
A small unobtrusive RCA ANT751 should be all you need for your channels of interest. It is a well built antenna that should last for many years. It also comes with a J-mount to install it on wall that faces the towers; or roof or gable end of the house.
Point it about 220° (117) or so, (compass direction).

montl,
Thanks for posting your results. It's always good to hear how things turn out.

So I am thinking a gray hiverman for the uhf band
http://www.digitalhome.ca/forum/showthread.php?t=81982
Is a good bet foe me.

I haven't looked through the tophat stuff yet but would that get me the vhf-hi bands?

Impossible to predict attic reception. It might work, though.

Is there thermax up there?

Yes. The latest optimized models are here:

http://clients.teksavvy.com/~nickm/gh_n3_uV.html

As you can see, the NAROD with NAROD reflector models compete very favorably with the vhf-hi antennas listed here :
http://www.hdtvprimer.com/ANTENNAS/comparing.html

In an attic, you lose from 6 to 25+ db in gain, no matter the antenna.

Hi,
I live in a valley 45 miles or so from stations with very fringe reception. I put up a 40 foot tower with XG91 antenna and Channel Master CM7777 preamp. For a long time my digital channel 19 was always solid but recently I have been having dropouts. I do have a rotator on this setup and according to the signal meter on the TV it will be 3/4 scale but every so often go to zero and dropout for awhile then come back up.

My channel 31 does the same thing and sometimes is not there at all. I realize this might be from conditions and also every time an airplane flies between my location and the transmitters.

Since XG91 is so high gain , does anyone think that using an 8bay type uhf antenna will help my reception ? I climbed up the tower a couple weeks ago and checked all my coax connections to try and rule that out ( thanks to warm January in Wisconsin weather !) .

This is my TV Fool report
h ttp://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d67d9dd7a9f0ebe

Thank you for any help .

haven't peeked up there, but will tonight. I think the thermax was just lined on the walls and fiberglass in the attic.
I am kinda stuck with my setup, its really windy around here and I believe we have hit 50mph winds or to the point where the attic shakes. I don't want to put one on the roof but if I did I could put a whole bunch of nerd toys up there like some weather gear or a wifi antenna.

it is tempting.

edit-no thermax, just yellow fiberglass

Thats pretty much symptomatic with 2 edge, negative NM channels.

What can help is to tilt the antenna so it aims towards the top of the hill.

For airplane flutter, vertical stacking can help reduce the effects, plus give about another 2.5 dbi in gain.


Since those channels are real RF 30 and 48, nope. It would be more cost effective to stack what you already have.

> attic or other indoor reception of VHF channels is sometimes much
> more difficult than UHF, because UHF penetrates building materials
> more easily

This is incorrect. Building materials (and trees, etc.) attenuate
higher frequencies more than lower frequencies. UHF is higher frequency
than VHF. Some materials attenuate more than others.

It *might* be that UHF can get through a hole (like a window)
that a lower frequency signal (like VHF) can't. Compare the
width of a VHF-LO antenna with the width of a typical window.
Just a theory, I haven't tested it.

> I would get an antenna designed for both VHF & UHF

Seperate antennas work better than a combo.

Antennas with good reputations that are worth considering:
VHF-HI:
Antennacraft Y10-7-13
Weingard YA-1713 http://www.hdtvprimer.com/ANTENNAS/w1713.html
UHF:
AntennasDirect DB8 http://www.hdtvprimer.com/ANTENNAS/DB8.html
AntennasDirect XG91 http://www.hdtvprimer.com/ANTENNAS/XG91.html
Channel Master 4228 http://www.hdtvprimer.com/ANTENNAS/cm4228.html
Weingard PR-8800 http://www.hdtvprimer.com/ANTENNAS/w8800.html

Some of these have changed names and/or designs. I think the PR-8800
is called something else now, and the 4228 was redesigned somewhat.

If you want to keep the new antenna in the attic, be sure and measure
the space available and make sure your chosen antenna will fit.

> every time an airplane flies between my location and the transmitters

Creating dynamic multipath, which demodulators have trouble with.

If the flight path is directly between you and the transmitter,
the main thing I can suggest is to try different demodulators
hoping to find one that handles dynamic multipath better.

You can try aiming the antenna lower/higher, or left/right, depending
on where the flight path is.

If the flight path is not directly between you and the transmitter,
read up on the "two antenna trick" (hdtvprimer.com) and try and aim
a null at the flight path.

> Since XG91 is so high gain , does anyone think that using an 8bay
> type uhf antenna will help my reception ?

The 8800 has more net gain at lower frequencies, but less at higher
frequencies. Only slightly more at RF30, less at RF48. I have the
8800 in my attic, it does well, but in hindsight I'd rather have the
XG91 for more gain at higher freqs. The 8 bays have different
radiation patterns than the yagi XG91. The different radiation pattern
might help, although I suspect you'd be better off getting another XG91
and trying the two antenna trick.

Indoor reception of VHF is more difficult than UHF. UHF can pass through a window or other opening easier than the longer wavelength VHF. In addition to difficulty in "finding a way in the building" VHF is much more prone to dropouts from electrical interference common in many buildings, than UHF.

> Indoor reception of VHF is more difficult than UHF. UHF can pass through
> a window or other opening easier than the longer wavelength VHF. In
> addition to difficulty in "finding a way in the building" VHF is much
> more prone to dropouts from electrical interference common in many
> buildings, than UHF.

It depends on the building. If the walls attenuate UHF a lot, but
don't attenuate VHF much, VHF can come in well, but UHF poorly.
If the walls attenuate VHF a lot as well as UHF, but there are holes
(doors/windows) large enough for UHF but not VHF, you might have the
opposite.

I'm kinda confused by these, I was looking at this guy http://clients.teksavvy.com/~nickm/g...6V9_14u65.html but I have no idea what those green lines indicate. I was just wanted to use a sheet of aluminum foil for a reflector on a hardboard.

The green lines are individual 1/4" diameter reflector rods.

On the GH NAROD models, NARODs provide the vhf-hi gain, only work with rod reflectors. The mesh and aluminum foil GH models are strictly uhf only.

The original SBGH with a 30" X 40" aluminum foil reflector works great for uhf.
http://www.digitalhome.ca/ota/superantenna/design.htm
Just follow the dimensions for the element, 7 inch legs, 5.6 inch stubs ( the feed point could be increased from 44 mm to about 90 mm for a bit additional gain). Make a 30"X40" cardboard reflector, cover it in aluminum foil (leaving a 1 inch vertical slit in the middle for additional gain) and space it 100 mm behind the elements. Attach balun in the middle of the elements and youre done.

Thanks balun, I figured out after posting the regular one may be the best at first. One if my neighbors had a big ass antenna on his roof and got a good chink of channels. Fox and nbc are ones that I am going to want so I most likely will need a roof mount.

Are amps generally frowned upon when dealing with this stuff? Also how thick of a coax connection is needed? Improved some cables are flimsier than others. I would guess we want a stiff one.

Hi all.

Love the thread.

My office is in Irvine Ca 45 mi from LA and 65 from SD. I am in a cement building with tons of computers.
I bought a HDTV box at w mart to go with a 10 year old 13" TV.

To just try it out I got the middle priced indoor rabbit ear antenna with a 6" square in the middle, a Phillips sdv6122/27 powered antenna. It was about 16 bucks and looks just like Quantum Amplified Powered HD/DTV/UHF/VHF/FM 230° Rotating Digital TV Antenna. The antenna sits on a plastic shelf 6 foot high 4 foot over the TV.

I was shocked to have gotten 60 channels. I am getting FOX SD on 11.? and Fox LA. As both LA and SD are in a line I don't have to move the antenna.
I have screened out the info channels and the languages I don't speak and still get 35+
I don't know if I have a freak or what but I love it.

It worked so good I bought a 24" flat screen and I now get a few extra channels.

I would love to hear opinions if I can do better. I told my son I would send an antenna to him at NC State.

Thanks

Great to hear you have a lot of success, but just because you got a lot of channels with that antenna does not necessarily mean your son would have the same success in NC. If he is close to the towers with line of sight, it should work. But your son can go into a local Radio Shack and get a similiar antenna. At least if it does not work, he can return it.

He never watches the TV so I was going to send him the one thats least works. I am wondering if I have a freak (good) antenna. If I can do better and if so with what?

Thanks

Poor amps are frowned upon to say the least heh, as they produce more noise than signal. If running coax for more than 30 or 40 ft, then a quality low noise preamp is a big help and an almost must have. Channel Master and Winegard have quality low noise preamps. Rat Shack ones are high noise and over priced.
Keep in mind, preamps only compensate for the losses after the antenna terminals (and in some cases, poor RF tuner amps in the TV). Typical RG-6 loses 1 db every 18 ft at 700 mhz, correspondingly less loss at lower frequencies. A good two way splitter loses 3.5 db and poor ones even more. A 3 way splitter typically loses 7 db.

RG-6 coax is fine for most installations and is lower loss than quad shield and the older RG-59. You only need quad shield RG-6 if running next to a noisy power line. RG-6 core wire is typically copper clad steel which gives it strength, but some swear by solid copper core especially for use with preamps. When installing, you want to use large bends and not pinch it.