Can somebody recommend a good outdoor diplexer?

[Pepper]

I just got done replacing for the 3rd time a diplexer outside. I have my OTA antenna diplexed into the FTA feed. Whenever I have trouble with various horizontal transponders I know that's the part I have to replace... again. I'm guessing something is happening and it's having trouble passing the higher voltage to switch to H polarity. Either that or something is wrong with the way I have it all connected and it's burning them out. I have never had to replace the diplexer inside the house.

My setup looks like this:

OTA & FTA rcvr --- diplexer ----- inside (wall) outside ----- diplexer --- antenna & motor --- DiSEQc switch --- LNBFs

 

[sidha]

Unless you have a really cheap diplexer I've never seen, it sounds more like corrosion on the F-connector fittings where they mate or near the coax. It doesn't take much.

-sidha

 

[Mike500]

You need one of these.....................

 

[Pepper]

Good suggestions. I had dead H transponders again today (Russia Today and AlJazeera on IA5) but everything else working. This time I disconnected the diplexer and reconnected it and they started working again.

I think a good weekend project will be to replace the three cable ends, tighten down everything real good and weatherproof it.

 

[bryansr]

I have found that if you pick up some Dielectric grease from an auto parts store and put a DAB in each coax connection prior to assembly. Your connections will not corrode and it will be MUCH easier to remove in the future. They do make a Teflon dielectric grease too but it costs more and a little harder to find.

BryanSR

 

[MrTim]

Good suggestions. I had dead H transponders again today (Russia Today and AlJazeera on IA5) but everything else working. This time I disconnected the diplexer and reconnected it and they started working again.

I think a good weekend project will be to replace the three cable ends, tighten down everything real good and weatherproof it.

I think you hit on the problem. RF travels on the outside of the conductor. Check your coax ends and look at the center conductor. If it's black colored, you probably have a problem. These should be cut back far enough to get nice clean copper and ends re-installed.

Electricity travels through the conductor so while it may seem everything is working okay, the RF may not be able to jump the corroded conductor. Removing it and reinstalling it may cause it to work again, BUT this problem will re-appear as the corrosion continues to worsen.

 

[mrweather]

I think you hit on the problem. RF travels on the outside of the conductor.

Also known as the "skin effect" especially at the frequencies used to carry satellite signals.