Quote:
Originally Posted by DTVuser2009
It wasn't raining but it had just stopped raining and the signal was a flat '0' when it normally is in 80-83% range. it was so steamy outside that the windows were fogged out. i may just find an old rusty Dish antenna and use the waterproof cables from it. would be a perfect replacement.
Once the sun shines the next day the signal slowly climbs back to normal range and stays there as long as the humidity stays within a certain percent. i think high dewpoints cause some of the problem moisture.
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I can have seen this on my satellite cables. I put in the dish in the late 90's using crimp style f-connectors. I "sealed" them with goop. They stayed sealed for a few years. Then after it rained, no satellite. At first they dried out right away. Soon it got to the point it took days to dry out. Then it didn't even have to rain but be very high humidity.
Then it hit me what another ham had told me years before that made his own amps, antenna and stuff. He said never ever try and seal a homemade preamp you put up on a mast. He said during the day, the higher temps do two things. One they expand any air inside a sealed container. They also lower the relative humidity. This allows some moisture to be expelled but not all compared to what happens at night. One night hits, the temp drops, the relative humidity goes up. Then the sealed container cools, the air in it cools drawing outside air laden in moisture. Even worse since it had been hot, the temp change or delta is even greater, causing it to suck in a lot of wet air.
Then over time it pulls in more moisture than it expels until you have a failure.
Knowing that ever notice that commercially made preamps for home installation are not sealed?
Since the cable TV industry uses more RG6 than anyone, they learned a long time ago the same thing happened to cables made with crimped F-fitting ends. Most cable companies and satellite installers switched to better crimps, and it was better but not good enough. Then they found changing to the new compression fittings sealed much better. Their maintaince time when way down.
I have a RG59 coming down from my antenna. There is a barrel in the middle before the bottom of the drip loop, so water pours over the connection when it rains. I have had it there 2 years and can open it and there is no water inside. If you put a compression fitting on right the PVC jacket is pushed into the rear of it and forms it's own seal, much like a cylindrical o-ring.
I believe in them so much I gave away all my old crimp connections but kept the crimper (tool collector mentality)
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