Power Supply for PreAmp affecting reception?

[JimInAmesIA]

Hi, I have two antennas, a GE attic antenna with GE amp right at the antenna and RCA ANT751R Outdoor Antenna on a mast with an RCA TVPRAMP1R Outdoor Antenna Preamplifier into which both antennas are connected. I get all my channels very well except for WOI TV 5 which is only 15 miles away but is a low VHF channel and pixalates a lot. I've found all the other channels come in just as good without the RCA preamp but 5 won't come in at all, but when I moved the power supply from my downstairs TV to my upstairs (on which 5 plays well most of the time) I couldn't get 5 upstairs at all. I began to wonder if the power supply was interfering with the VHF signal since it must travel through the supply to the coax connection to the TV, or if the electrical supply has a short. I connected the coax from the antennas to a 2 way splitter then to one output I connected the coax to the TV and to the other I connected the power supply. This seems to help the pixalating on channel 5 some.

I'm wondering if anyone else has experienced anything like this?

[GroundUrMast]

Can you post a link to your TV Fool report?

What is the model number of the GE antenna, and the GE amplifier?

Have you ever tested the basic reception of the antennas? By connecting just the antenna to one TV, no amplifier or power supply parts, and no splitters.

General observations:

Very few systems have a legitimate need for two amplifiers. Many systems would be better with none.

Combining dissimilar antennas that cover the same band (UHF, High-VHF and Low-VHF) quite often causes more reception problems than it solves.

Powering an amplifier via the coax with a splitter in line requires the use of a power passing splitter.

[JimInAmesIA]

Have you ever tested the basic reception of the antennas? By connecting just the antenna to one TV, no amplifier or power supply parts, and no splitters...Very few systems have a legitimate need for two amplifiers. Many systems would be better with none.


Yes I have. I get excellent reception on all channels except WOI 5 which now also seems to be doing much better after I put the splitter between the preamp power supply and coax into TV.

Combining dissimilar antennas that cover the same band (UHF, High-VHF and Low-VHF) quite often causes more reception problems than it solves.
Powering an amplifier via the coax with a splitter in line requires the use of a power passing splitter.

Without either amp or preamp I can't get channel 5 at all, the preamp gives me a better picture on the other channels but the amp seems to have no effect.

[GroundUrMast]

Can you post a link to your TV Fool reception report? http://forum.tvfool.com/showthread.php?t=4

What is the model number of the GE antenna, and the GE amplifier?

Thanks

[JimInAmesIA]

Can you post a link to your TV Fool reception report? http://forum.tvfool.com/showthread.php?t=4
What is the model number of the GE antenna, and the GE amplifier?
Thanks

Hi again GUM.

Is this what you mean by my Fool Reception Report?
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d2df974d491cd25

Thanks for making that available btw, it was very useful in aligning my antennas when it showed me all the channels I wanted were pretty much in a line 170-173 degrees.

GE Antenna 34792 http://www.walmart.com/ip/GE-Attic-Mount-Antenna/20976617
GE amp 33341 http://www.walmart.com/ip/GE-Video-Signal-Amplifier/16561353

I'm no longer having any reception problems, not even with WOI 5 after I added the splitter to move the RCA preamp power off the direct coax into the TV.

My question was concerning if such preamp power supplies with the coax running through them to the TV ever cause reception problems perhaps due to shorts or malfunction of the power supply itself? I asked since, I think as I already wrote, when I moved the power supply to the other TV the problems with WOI 5 moved with it.

It's a pain I need all this hardware for the one channel but I do want to be able to get it in, seems I am now.

[GroundUrMast]

Thanks for posting your TV Fool report. It helps a great deal.

To answer your question re. preamp power supplies, you need to follow the manufacturer's instructions carefully in order to avoid sending power into the TV tuner. In some cases the preamp power supply could be damaged due to high current into a low DC resistance in the tuner input. In some cases, no damage will occur, but the DC current will magnetize the input transformer core in the tuner. If this is the case, the input transformer may not pass much signal to the internal stages of the tuner circuitry.

Preamp power supplies usually consist of a wall transformer, and a 'power injector' which may look like a splitter, but it's not a signal splitter. The power injector is designed to send power 'up' the coax while preventing signal from traveling into the wall transformer.

After looking at your TV Fool report and seeing the model number of the antennas you're using, I can see why you have had a hard time with WOI reception. Neither the GE antenna nor the RCA antenna are designed to receive real channels 2 through 6 (Low-VHF band).

A single combination UHF/H-VHF/L-VHF antenna would be able to get the job done... with no amplifiers needed.

Several 'all channel' antennas come to mind, Antennacraft C290, Channel Master CM-3016 and Winegard HD7010. Mounted outside in the clear, you should have enough signal power to drive at least four sets through a passive 4-way splitter.

[JimInAmesIA]

Thanks for posting your TV Fool report. It helps a great deal. To answer your question re. preamp power supplies, you need to follow the manufacturer's instructions carefully in order to avoid sending power into the TV tuner. In some cases the preamp power supply could be damaged due to high current into a low DC resistance in the tuner input. In some cases, no damage will occur, but the DC current will magnetize the input transformer core in the tuner. If this is the case, the input transformer may not pass much signal to the internal stages of the tuner circuitry. Preamp power supplies usually consist of a wall transformer, and a 'power injector' which may look like a splitter, but it's not a signal splitter. The power injector is designed to send power 'up' the coax while preventing signal from traveling into the wall transformer. After looking at your TV Fool report and seeing the model number of the antennas you're using, I can see why you have had a hard time with WOI reception. Neither the GE antenna nor the RCA antenna are designed to receive real channels 2 through 6 (Low-VHF band). A single combination UHF/H-VHF/L-VHF antenna would be able to get the job done... with no amplifiers needed.
Several 'all channel' antennas come to mind, Antennacraft C290, Channel Master CM-3016 and Winegard HD7010. Mounted outside in the clear, you should have enough signal power to drive at least four sets through a passive 4-way splitter.

Of the antennas you've suggested

WINEGARD HD7010 2-69 VHF/UHF 30/45 miles $45.94 (free shipping)
Channel Master CM-3016 2-69 VHF/UHF 45 miles $39.99 + $7.49
Antennacraft C290 2-6 VHF 55 miles $45.39 + $9.55

All have specs no better than and in some cases worse than either antenna I purchased though I paid less for both antennas combined than any one of them (I had to of course pay for the amps but given reception claims are comparable I'd have likely needed them anyway and with the Antennacraft I'd have needed a UHF antenna) The splitter I am using on the RCA preamp power source is a GE 2 way 5-2500mhz (model 87623) not allowing currect to back up into the TV but transferring it effectively to the preamp which was a true concern of mine.

In any event I am getting all channels crystal clear now

[GroundUrMast]

It's hard to argue with success.

You're correct, the UHF and High-VHF performance of your existing antennas matches or exceeds those I've suggested. The critical difference is that each of the suggested antennas includes support for Low-VHF. Hopefully your current system will continue to provide reliable reception. If not, the antennas I've mentioned are appropriate solutions when mounted outside in the clear.

Cheers

[JimInAmesIA]

It's hard to argue with success.
You're correct, the UHF and High-VHF performance of your existing antennas matches or exceeds those I've suggested. The critical difference is that each of the suggested antennas includes support for Low-VHF. Hopefully your current system will continue to provide reliable reception. If not, the antennas I've mentioned are appropriate solutions when mounted outside in the clear.
Cheers

Hi again GUM

Just thought I'd let you your responses did give me some added food for thought and while, as I wrote previously, I tested the splitter I was using with my preamp power injector and found no voltage going to the TV, after reading your warnings about possible damage to my tuner I purchased voltage block couplers for both coaxials to my two TVs. I'm attaching a pic of my power injector set up to hopefully make clearer what I did. This is an RCA injector which has a built in coaxial with blocker for connection to the TV but I think mine was malfunctioning, it either had a short in the signal flow or it was leaking voltage into the TV because it make interference on whatever TV it was attached to per instructions. But it did seem to deliver appropriate power to the preamp so I redirected the TV signal around the injector with a splitter.

My reception on all channels is awesome now and I think my TVs are safe as well.