Channel Master CM-7779HD PreAmp

[JohninSD]

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.

 

[primestar31]

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.

Buy this one, I have one, and it's far superior to just about anything else out there: Televes 560383 Single Input Antenna Preamp, 5G Cell Filter, Coaxial F-

Or Amazon link: Amazon.com

 

[Radioguy41]

Have you double checked the power inserter connections? Power In/To TV/To Amplifier. Does it make a difference whether the switch is set to Hi or Lo gain? Is the amp indoors or mounted on the antenna outdoors? I have a CM7777 mounted on my antenna for 20 years now without a hitch, they are good, robust units so I suspect something else is going on, in fact it sounds suspiciously like the amp is overheating.

 

[JohninSD]

It's on the antenna mast up on my roof. I had the same thought about overheating. As of now I've ordered and received the Televes unit mentioned above, haven't installed it yet. Will post results when I get it installed.

 

[JohninSD]

Just installed the Televes preamp. When I put it up on the antenna mast I received no channels on any TV in the house. The power LED on the outside unit (mounted on the mast) seemed very dim but I attributed that to the brightness of a sunny day. Out of curiosity I moved the unit inside and attached it right at the main TV, then scanned again. This time I got about 60 channels and the main ones that I watch regularly are much clearer and have more signal strength and quality than they had without the preamp. So I'll leave it connected for now and see what happens. My theory is that the cable from the antenna may be getting old and need to be replaced, a job I don't anticipate with pleasure. The 12 volt power from the inside unit to the outside unit may be down to too low a voltage to properly power the outside unit when it is up on the mast and the power has to travel through roughly 70 feet of cable and a 3 way splitter. And yes it is a power passing splitter. Hmmm maybe the splitter is lowering the voltage but I'm not going to investigate any further right now.

 

[primestar31]

Just installed the Televes preamp. When I put it up on the antenna mast I received no channels on any TV in the house. The power LED on the outside unit (mounted on the mast) seemed very dim but I attributed that to the brightness of a sunny day. Out of curiosity I moved the unit inside and attached it right at the main TV, then scanned again. This time I got about 60 channels and the main ones that I watch regularly are much clearer and have more signal strength and quality than they had without the preamp. So I'll leave it connected for now and see what happens. My theory is that the cable from the antenna may be getting old and need to be replaced, a job I don't anticipate with pleasure. The 12 volt power from the inside unit to the outside unit may be down to too low a voltage to properly power the outside unit when it is up on the mast and the power has to travel through roughly 70 feet of cable and a 3 way splitter. And yes it is a power passing splitter. Hmmm maybe the splitter is lowering the voltage but I'm not going to investigate any further right now.

Mine is powering through over 100' of Rg-6 Quad shield cable, with proper compression connectors and such, and having no issues. I'd say you need to check this out when you get a chance. Perhaps re-run all new cable the whole length.

 

[Stuart Sweet]

Quad shielding on a TV antenna cable isn’t going to hurt you, of course, but it’s not likely that there’s enough EM interference in that range to make a difference between dual and quad shielding. It’s much more important that the center conductor be solid copper. Home Depot and Lowe’s sell cables with a copper clad steel center. There is far more voltage loss on that kind of wire, and it could cause undervoltage to the preamp.

I have one of those amps myself. We were one of the first companies to bring Televés to the US and we did it because of their superior quality.

 

[primestar31]

Quad shielding on a TV antenna cable isn’t going to hurt you, of course, but it’s not likely that there’s enough EM interference in that range to make a difference between dual and quad shielding. It’s much more important that the center conductor be solid copper. Home Depot and Lowe’s sell cables with a copper clad steel center. There is far more voltage loss on that kind of wire, and it could cause undervoltage to the preamp.

I have one of those amps myself. We were one of the first companies to bring Televés to the US and we did it because of their superior quality.

I also do FTA satellite, and buy the quad-shield coax by the 1,000 foot reel. From YOU guys in fact... So, I also use it for my OTA antenna system.

Two newest

(top one at 42') Televes Dat Boss Mixes, and an older Dat Boss UHF only. All run into a Televes SmartKom, and each of them picking up a separate DMA.

 

[W6MMS]

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.
So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.

it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm no

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.

So I got this preamp and installed it, worked great I thought, my TV saw 88 channels on the initial scan with the preamp, vs. 32 channels without it. The only problem is that it only works for a few hours at a time, then something happens and all channels disappear. Unplugging the preamp doesn't even help, I have to physically disconnect it and run the coax directly to the tuner, then I get the original 32 channels. So it's going back to Amazon. Maybe the amp has a heat problem, maybe the power inserter has a problem, I'm not interested in further troubleshooting. Just an FYI if anyone gets one of these.

The cautious and conservative installation process would include cutting back the coax and installing new F connectors. I just successfully installed this preamp and the connectors as well as the coax appeared to have some corrosion. Ideally this is also the time to replace the old coax. Further, F connectors come in versions for RG-59, dual shield and I now see a product tailored for quad shield RG-6 coax.

Technicians I’ve observed who are interested in leaving things working for a long time usually take this approach. I used to wonder why but now I’m a believer.

Weather protection with connector tape is a good idea.

Not that things can’t work with shortcuts, but why not defer problems?

Craig

 

[Tvland1]

The 12 volt power from the inside unit to the outside unit may be down to too low a voltage to properly power the outside unit when it is up on the mast and the power has to travel through roughly 70 feet of cable and a 3 way splitter. And yes it is a power passing splitter. Hmmm maybe the splitter is lowering the voltage but I'm not going to investigate any further right now.

Am I understanding correctly that you have a splitter between the mast amp and the power supply? The power supply on the Televes has 2 outputs and if your going to use a splitter that is where you should have it located. After the amp..nothing between the amp and the power supply even if it's power passing

 

[JohninSD]

I now have the Televes up on the roof about 3 feet from the antenna. From there the coax goes to a 3 way splitter and then into the house in 3 separate locations. It is a new Channelmaster power passing splitter and the preamp works great now. I did replace the RG6 coax from the splitter down to the location where the power supply is located next to the main TV - guess I should have done that first - oh well it works now. The coax from the antenna to the splitter is about a year old but the coax to the other two house entries has been there for ten years or more - still working well enough for the bedroom and kitchen TVs though.