Need Pro Help With Modulated Channel(S)


SatelliteGuys Guru
Original poster
Oct 12, 2005
Covington, La
My 622 is set up in dual mode. I am using a channel plus modulator to distribute my cable signals throughout the house. It is a 2 piece unit with a modulation unit & a distribution head. On the distribution head there are 3 inputs (1 for antenna, and 2 for modulated signals) & 8 outputs. I used to modulate my DVD player, VCR, and 501 to every TV in the home. Now with the 622 there is little need (& DVD players got cheap to put in other rooms).

I have my over the air antenna feeding locals into one input, the 622 TV2 output into another, and the modulator output into the 3rd. The antenna signal is amplified with a Winegard 2 piece indoor/outdoor amp. The outputs are home runs to various locations in the house. Currently only 3 other TVs & a computer are being used.

My problem is this - the antenna signal is perfect on every TV in the house almost all of the time (except for weather). The modulated signals we watch on TVs other than the main living room TV (whether from the modulator or the 622) are all over the place at random times. Sometimes they are clear as a bell, while other times I get scrolling vertical bars (from Right to left) & a ton of snow. The pattern is very rhythmic.

This happens randomly at any time of day or night, and at different intensity levels from annoying to literally losing the signal & getting a blue screen.

My first thought was bad connections or electrical interference, but at the same time the antenna signal is clear. I have wondered if there is a local ham operator stepping on the signal, but lack the expertise to really know. there is a cell tower about 1/2 mile away, and other than that Charter Cable has a satellite farm about 2 miles away. Seems unlikely.

I have tried attenuators, FM traps, etc. as recommended from channel pluss'es website, all to no avail.

Do any of the installers on this site have any ideas for me, or know an expert in the Covington, La area that I can hire? I am hesitant to just hire someone blind out of the phone book.

This is driving my wife nuts, and me too. Any help would be greatly appreciated.
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What channels are active in your area and what channels are you using for the modulated channels? Do you have any HDTV channels available OTA?
One of the inputs is probably going bad. I use a channel plus also and the same thing was happening on mine except it was the antenna input I believe but I was having the same issues you describe on the outputs to my sdtv's . I have replaced it twice only to have it happen again after 2 or 3 months. I eventually just bypassed it and put a splitter with my antenna feed on the outputs for the rooms where I need OTA to the hdtvs, and am just feeding the 622 into it. I have very good picture quality and no problems now. Try disconnecting each of the inputs one at at a time and see if it clears up.
Thanx guys - I have tried the modulated outputs on many different channels to no avail.

I went by a local lumber company with a home theater department this morning & happened to catch one of their installers who seemed pretty knowledgable. His first guess was that the modulator is going bad.

I'm going to try taking it out of the loop tonight to see what happens.

I also stopped several places to look for a decent quality (low db loss) 8 way splitter to replace the modulator-specific splitter. There wasn't much to pick from.

The best thing looked like a distribution amped 8 way splitter from Leviton that fits their structured wiring box (from Home Depot). Non of the splitters I could find gave specs about signal loss on the package.

Is it cool to just run the amplified antenna input into the 622 - then the TV2 output to an 8 way splitter with an adjustable gain distribution amp built in?
SouthRider said:
Is it cool to just run the amplified antenna input into the 622 - then the TV2 output to an 8 way splitter with an adjustable gain distribution amp built in?

This sounds fine. I'd go one step further, though. Split the signal from the OTA antenna before it enters the 622, and run it to a combiner (splitter in reverse). Run the modulated TV2 output into the combiner, and then run the combiner output into the distribution amp. Make sure the distribution amp is a good quality one, or it will screw up your OTA digitals.

I ended up removing the modulator completely, and bought an un-amplified leviton 6 way splitter (the only 8 way I could find had a built in distribution amp & was $149). I can order the 8 way later.

I already have my antenna feed split before the 622. I had considered doing away with combining it if it degraded signal quality - it didn't. First I tried an old SC-3 signal combiner from my first Dish install 10 years ago (it has adjustable gain to the inputs).

It didn't make a noticeable difference, so I ended up using a Terk low loss 2-way splitter in reverse. This gives very acceptable results that are much better than the combiner or the old modulator setup.

I still have one minor quibble that I wouldn't mind fixing. The TV2 SD signal seems to have a slightly muddier picture than my OTA antenna - in other words the colors seem to lose their "pop".

I tried using an old radio shack adjustable gain (-5 to +25) amp that I had - putting it in between the 622 & the splitter/combiner (seems like I shouldn't over amp a good antenna signal).

There was NO noticeable difference.

My question: are there distribution amps specifically designed for the frequency of SAT signals? Or - do the ones recommended for cable & cable modems work?

Does anyone have any recommendations.

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