Warm weather= 57 channels, Cold Weather= 2 Channels!?

nbound-au

The Graveyard Shift
#41
My money is on the CM7777, the balun is just a special transformer wrapped in plastic, and if there were no physical signs ofdamage or corrosion, is almost definately fine.
 
J

Jim/Tennessee

Guest
#44
Same Cold Weather Problem - Losing Stations

Old post I know, but I've got the same issue. I'm losing channels when the temp goes below 34 degrees. I'm also using the CM7777, but my antenna is in my attic. Anyway, today it is 28 degrees so no channels coming through on my tv. I got a hair dryer and heated the CM7777 and guess what....I got all my channels back.

This is my second CM7777, I replaced the first one hoping this would solve my cold weather problem. I'm thinking both of them are bad.

Any suggestions for a different brand preamplifier with similar gain?

Thanks - Jim/Tennessee
 
J

Jim/Tennessee

Guest
#46
Actually, it is all in my attic. So, the antenna and pre-amp is all protected from the wind/rain, but still subject to cold weather.

I found a Winegard AP-8275 for sale. It looks to have similar specs to the CM-7777. Does anyone have experience with this pre-amp?

Also, I notice on the Channel Master web site there is a new version of the CM-7777, the CM7777HD. I would just buy this new unit, but I don't want to buy another product that does not work in cold weather.

- Jim
 
K

KyleT

Guest
#47
Actually, it is all in my attic. So, the antenna and pre-amp is all protected from the wind/rain, but still subject to cold weather.

I found a Winegard AP-8275 for sale. It looks to have similar specs to the CM-7777. Does anyone have experience with this pre-amp?

Also, I notice on the Channel Master web site there is a new version of the CM-7777, the CM7777HD. I would just buy this new unit, but I don't want to buy another product that does not work in cold weather.

- Jim
Why don't you put the pre-amp against the ceiling and cover it with insulation?
 
K

KyleT

Guest
#48
Why don't you put the pre-amp against the ceiling and cover it with insulation?
Oops! If you haven't done this, please do not try it at home. Mine turned quiet warm after placing it under 9" of insulation for about 4 hrs. Anyway, the matching transformer (balun) is the culprit, not the TV signal booster.
 
#49
I went ahead and purchased the CM-7777HD. I installed it and right away started receiving one of the stations I had lost when the weather turned cold, so I'm encouraged. I also notice that the signal strength indicator that my Samsung tv gives me for each station shows a much stronger signal for each station.

The real test will be when the weather turns really cold again. The day I installed the new amplifier, the temperature was 58 degrees. We'll see what happens when it the temperature drops below 34 degrees.
 
K

KyleT/Seattle

Guest
#50
I went ahead and purchased the CM-7777HD. I installed it and right away started receiving one of the stations I had lost when the weather turned cold, so I'm encouraged. I also notice that the signal strength indicator that my Samsung tv gives me for each station shows a much stronger signal for each station.

The real test will be when the weather turns really cold again. The day I installed the new amplifier, the temperature was 58 degrees. We'll see what happens when it the temperature drops below 34 degrees.
Jim,

I have no doubt that your signal booster is not the one causing problem. When the temperature drops below mid 30s you will see a few channels disappear again.

At this time I can say for sure that your matching transformer (balun) is the culprit.

The bad news is that you will not be able find any replacement balun on the market which can fix the disappearing channels.

A balun consists of two (insulated) copper wires winding around a ferrite magnet core. In theory, it would last forever but in reality, the ferrite magnet core loses its property when the temperature drops and the result is that TV signal passing through it would loose its strength.

The good news is that there is a way to resolve it: You will need to move the matching transformer to a warmer place, like under the insulation or inside your house. I chose the second because my antenna is inside the attic and right above the closet.

You can use either the "cylinder" or "block" shape indoor balun. (The "block" shape is the one came with older TV to attach bow-tie antenna to the back of the TV.) I chose the "block" shape matching transformer because it can be attached directly to the signal booster. I made two long lead wires out of RG-6 cables by striping about 3/4" at each end of the cables to the expose the copper cores and attached one ends to the antenna and the other ends to the balun. Please note that you must use shielded cables to connect your balun to the antenna.

So far my TV signal is really stable even the outside temperature has been down to low 30s at night.
 
#51
Thought I would post an update.

It is 10 degrees this morning and we are still receiving all of our stations. It has been below freezing for a couple of days now and we have had no problems.

Looks like replacing the CM-7777 with the CM-7777HD fixed our cold weather issue.
 
T

Techtom

Guest
#52
I had the same problem till I ended up wrapping the outdoor portion in insulation and covering it with a plastic bag. Haven't lost signal or strength
 
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