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post #5 of Old 06-14-2007
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Originally Posted by Terah

I've recently installed a new aerial (old cable was rotten)
Must've been very old cable. It was all inside the mast or cabin, no? Should've lasted until about the heat death of the universe. (Unless you had a leak at the top of the mast, in which case water may run down the inside of the jacket--and that'll destroy coax for certain. And in relatively short order!)

Originally Posted by Terah
and am having problems with signal strength, both transmitting and receiving. When receiving there is a hiss that disappears if I ease the plug out of the set so the conductor is still connected but the braid is not.
That doesn't make sense. FM VHF radios have a (almost always adjustable) "squelch" control. With that set just on "the edge" of squelching, you may well experience the radio going into and out of squelch as you mess with the antenna connection, but, other than that, the "air noise" shouldn't change appreciably with the antenna connection.

At least not in the direction it is for you. Now, if the antenna or coax is shorted, the "hiss" may disappear when you plug in all the way.

Originally Posted by Terah
I've replaced the plug at the radio end of the cable, and also the through deck plug/socket, and tried another aerial and the hiss persists which seems to narrow the problem down to the cable but I'd appreciate any thoughts on the possible cause before I rip out the cable and purchase yet another one.
Disconnect the connector at the radio and deck. Put an ohmmeter across center conductor and shield. It should measure infinity (open). Short the far end (alligator clips work fine). You should measure nearly zero (0) ohm resistance. Unplug the cable from the antenna end. Do the same for that segment. Plug the cable into the thru-deck connector and test the entire length the same way.

If all that behaves as it should, oods are either the radio's defective or the antenna is, probably. Antennas of this type are pretty simple affairs, so I'd tend to suspect "radio."
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