Radio Antenna Connection

mkendrick · Posted: Thu Oct 18, 2012 11:43 am Post subject: Radio Antenna Connection

In preparation for the arrival of my first form fitting cover for my 25' I unscrewed my radio antenna, which is positioned directly above the center window, and discovered a loose wire that had been slightly stripped at the end. Upon looking up the base of the antenna itself I noticed a rubber sleeve that I assume helps protect the wire. Although the wire did not look as if it had been twisted off due to unscrewing the antenna, I nonetheless thought that I had somehow disconnected it from inside the antenna. In an effort to see if I had disabled my radio I inserted the wire back into the rubber sleeve and screwed it back on. Using a back-up handheld radio I tried sending back and forward between the handheld and the stationery radio on the boat. To my amazment both transmissions worked. Although a good adage is to leave things alone if they are working, I want to know if the wire actually stays loose and is not connected to anything. Don't want to be surprised by a future failure on the water. Thanks for any help out there in C-Brat World.

rogerbum · Posted: Thu Oct 18, 2012 12:23 pm Post subject:

Without seeing an image, it's hard to diagnose but if the wire to which you are referring is the center conductor of the coaxial cable, it definitely shouldn't be loose. The test you performed was done at very short range and doesn't really mean much - e.g. a crappy tiny antenna will pick up and transmit signal over the range of a few feet. If you're within 10 miles or so of water with active boaters on the water or within a similar range to a marina, get on a working channel and ask for a radio check. If you get a response, ask for their position and you can get a sense of the range of your antenna.

thataway · Posted: Thu Oct 18, 2012 12:38 pm Post subject:

agree with Roger. Even the coax may pick up the transmission. If there is a severe mismatch the output of the radio will decrease to protect the finals.

There is not normally a loose wire in the base of the antenna. A "J" pole antenna may have a stub which is not the main radiator and be slipped into the base of the antenna. This would be shorter than the radiator and be attached to the base coax.

If you know a ham radio operator with an antenna analyzer, I would have the antenna checked out. A SWR meter will do a rough test--but a MFJ antenna analyzer will do a far better job.

colobear · Posted: Thu Oct 18, 2012 1:31 pm Post subject:

I recently had to replace the antenna on my VHF for exactly that reason. The coax had come apart from the antenna itself within the fiberglass shell. It should be firmly connected (soldered) not loose. My radio would transmit and receive just fine at short range but not at medium to long range. I contacted Shakespeare who confirmed the problem and told me that the stainless steel end was epoxied to the fiberglass cover and could not be removed to reconnect the coax to the actual antenna. So...a new antenna and a huge difference in performance.