Question: Preamp or not?

#1

Hello.......
Recently dusted off my TV after sitting for 10 yrs.
Have an old Maganvox 13" color crt unit.
Also have an Access HD DTA1010 digital converter.
Have constructed 3 DIY antennas & am currently using an omni directional that pulls in quite a few signals.
Have noticed that on my stations that are 50 miles & farther, the signal will come & go. Station might be on for an hour & then it will fade out, may come back on anywhere from 10 minutes to a few hours later.
Would a Preamp help keep the stations on longer?
My antenna is a bit over 30' in the air (9' above rooftop) with some trees nearby.
Clear view of North & West.
Terrain here is mostly flat. NW Ohio.
I have 4 local stations within 10 miles of home.
Would appreciate any ideas/thoughts to enhance my stations on time. :bowdown:
TV Fool







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U

Unregistered

Guest
#2
Low Noise Pre Amp.

There is an excellent Low Noise pre amp for under $100 US Dollars. But it may not help as you have strong signals from very near by. I would add a 2nd directional antenna with rotator. I bought one of these and it seems to work. Ultimate TV Antenna Signal Booster, TV Amplifier, HDTV Booster! Guaranteed! It has high but not unlimited overload capability. I used a band pass filter in front of the pre amp as it is in use at a transmitter site, so I had to filter out very strong signals first.
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#3
One of the reasons your distant signals fade is that they are 2 edge. I would try moving your antenna around (N-S-E-W and up/down) to find a sweet spot. Although it may seem counter-intuitive, moving your antenna down for a 2-edge signal sometimes makes a big difference. there are 2 distant channels I don't get unless I lower my antenna 4 feet.

Can you describe your antenna, or post a picture and its dimensions? That may help us to design a better setup. If it's a 4 bay bow-tie, you could pair it with an identical antenna to make it 8 bay.

I would use a booster as a last resort only. If you DO use a booster, I would recommend a CM-7777 preamp.
 

dave73

DTVUSA Member
#4
Adding a pre-amp can help at getting those distant stations that come & go. I however would recommend that if you do that, that you either turn it off for local stations (if using 1), or have the pre-amp on one antenna pointed at Fort Wayne, & not amplify the one for the local stations. I have 2 antennas in my setup, due to 1 station transmitting south of me, & that antenna is needed to lock in the signal, as the main one will not pointed at Chicago. The antenna for 1 station is not amplified, while the one for Chicago is (the full powers don't need it, but select low powers do), & I have that diplexed into a Winegard CC-7870 combiner, while my pre-amplifier is an RCA TVPRAMP1R I bought from Menards. It works good, but I would say that the Channelmaster CM-7777 would be more promising if the extra gain is important. Before I go any further, but do you receive WLIO? That is your only VHF in that list that is local. If you can't get that one, those DIY UHF antennas (if they're all UHF antennas) may not work with this antennas. For that I would add the Antennacraft Y5-7-13 antenna for that. The other option if you're crafty enough, is to construct a small antenna just for RF 8 (WLIO 35.1). Also based on the last TSReader reading, it shows WLIO being dual 720pHD, & NBC must look like crap to only run about 8mbps, & downconverted to 720p from NBC's native 1080i resolution. Fox on the subchannel gets close to 11mbps, & usually will work for 720p.

Anyway, I'll let you look at my TV Fool chart, the sole station that I need a UHF antenna for WYIN at 184° while all my Chicago stations are at 330° & 332°. The pre-amp is needed for WWME-LD on RF 39, WESV-LD on RF40, W25DW-D on RF 25, & WOCK-CD on RF 4 (my antenna is optimized for Lo-VHF). Like you, you want Fort Wayne stations, & for me, I want to get South Bend stations at a later date. At least in Fort Wayne that the networks are all on full power stations (including Fox, which recently went on a subchannel to WISE-TV). Unfortunately since 1995, ABC has been on a low power signal, along with CW & MNT in South Bend, & won't get those networks from there. A pre-amp on my main antenna has helped me get WSBT on RF 22 pointed at Chicago (used to also get WNDU on RF 16 when that station was analog, along with WSBT-TV when they were analog on RF 22). I also included an attachment of my antenna array.
 

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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#7
:welcome: Watergate528

Aside from me, you are the only other person I have heard of who has tried a horizontal loop antenna to try to receive FREE OTA TV. My results were poor, most likely do to its' omni-directional nature and multipath signal reception. Question: how well does it work for you?

What are the lengths of your 'Vees' and their spacing? For today's UHF television band, the 'V' elements should be 10-10.5" and spaced around 9.5" away from each other. Your design is dual-directional, but you can achieve unidirectional reception and additional gain from your antenna if you add a reflector screen. You may not need to use an amplifier.

Jim

PS I hope your second chimney (where that antenna is mounted) is not being used as a chimney!



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#8
Jim.........
I have had very good results with the Hula Hoop antenna.
It is a shade over 26" OD. Made from 1/2" copper tubing.
Was trolling thru many searches & found this build. It beat my 4bay by 3-4 channels.
I pull in channels from all directions.
As for the whisker antenna, the "V"'s are 10" in length, 5.25" space @ outer end & the spacing is @ 9.5".
I have removed the whisker antenna & placed a basic "hoverman" at the base of the chimney 8' in height.
Picked up a few more stations with the hove versus the whisker unit.
I have them tied into an A/B switch that seems to work so far.
Have ordered a CM7777 preamp, see how that works out.
The old chimney is dormant.
Was thinking about building another hula hoop & mount it vertical just to see what it would do.
Also thought about replacing the #10 whiskers with 3/8" or 1/2" copper tube spikes.




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MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#9
Also thought about replacing the #10 whiskers with 3/8" or 1/2" copper tube spikes
For the 4-bay, You would probably be better off to use the #10 you have, or 1/4" copper tube at the most.
Dimensions are pretty good but I would consider making it out of durable materials, and try a reflector.
If the Hoverman works better for you, try it with a reflector, too.
 
#10
Will probably go with 1/4" copper tubing. Damn birds will mess that #10 up in no time.
Might redo the hoverman in 1/8" steel rod, bird proof it.
Clouds must be right, pulling in Battle Creek, Mi. like it was down the street.
I do appreciate ALL the input that has been sent my way.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#11
Watergate,

Here's a photo of my quickie "Project-Zero" antenna, vertically oriented. I can pull two screws and reorient it horizontally in less than a minute. It is an old original UHF Loop that came with along with a set I bought many years ago, so it's not sized for the current band. It did not behave (directionally) as I expected on any channel, possibly because the balun needs to be shielded by enclosing it in a metal box.

Do you have any more photos of your horizontal loop, especially how and where you feed it? Thanks in advance,

Jim





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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#13
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#14
Good eye! 2 half moons, that's the way the completed project was shown in the forum.
I thought about making it a complete loop, but figured I would give this a try first. Wouldn't take much to connect the loop together.
Built a Stealth Hawk today & am trying that out, kind of nice being able to switch back & forth between antennas.




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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#17
Interesting. Forum members HiDefJeff and FOX TV have been working on fractal antennas, but this is a variation I have not seen before and if its a sucessful design, it could easily be built at home. Please keep us posted about your test results using the one you built. :thumb:

Jim
 
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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#19
Watergate,

Omnidirectional antennas receive the 'strongest' signal as well as the same signal reflected from other directions (multipath) thus by definition or in theory your goal to build a good omni-antenna is a waste of time because "multipath interference" confuses digital tuners.

On the other hand, I consider myself to be an Imagineer and not an Engineer where their rules do not hold back my experimentation. Ptttth on that nonsense.

Odds are, in my location an omni antenna would have limited use BUT I have reviewed dozens of TVFOOL reports from around the Nation and some of them might be able to take advantage of an omni antenna -- if a good one existed.

Jim



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