Electrical Gremlin - VHF

[blynch]

Hi all, here's a new one. Tried to call out from my radio this weekend but every time I it the call button the radio display would shut off and the call would not transmit. Upon releasing the button, it would turn back on but reset to Ch. 16. My best guess is that it was experiencing a power disruption (or surge?) that was effectively turning the unit off and back on. I can't rule out an issue with the radio itself yet, but that seems less likely to me given that the radio is relatively new and the boat (a 1994 226) has some other electrical oddities from time to time like inoperative lights, tripping breakers etc. I think some rewiring will be in order this winter, but is there anything I can do to diagnose and fix the radio issue in the meantime?

 

[Hookup1]

Take the antenna off and try it. Maybe its shorted and when unit is keyed.

 

[seasick]

either the radio is bad or you have a corroded electrical connection on either the 12v feed or the ground.
When you transmit the radio draws a lot more current and if there is a bad connection that has high resistance that will cause a voltage drop, enough to shut down the radio. So work backwards from the radio on the power wires. If there is an in-line fuse, open it up and check for corrosion. Continue until you get to the fuse block (not the switch panel) and look again for corroded connections, connectors or the fuse sockets themselves.

 

[glacierbaze]

Take the antenna off and try it. Maybe its shorted and when unit is keyed.

I heard many years ago that you never key the mike with the antenna disconnected, or you might blow the transmitter. I believed it, b/c I didn't know any better, and still don't, but I still don't do it.

 

[Hookup1]

I don't know if it's true either. If you are concerned you can do several things. Put in 1 watt mode - see if the problem changes. Get another antenna and try it. Buy a stubby antenna and try it. Heck - the things broken - just try it! It's possible it is just a bad connection - check them or take the harness out and connect directly to the battery.

 

[blynch]

Thanks for the wisdom all, heading down to the boat tonight and will start trying things out.

 

[seasick]

I doubt it is the antenna. In the old days it was a bad idea to transmit without the antenna or a dummy load connected. I don't know if todays radios protect against that situation but I personally wouldn't try it to see what happens. Even if the final amp stage blew out, that most likely won't not cause excessive current draw.
Check the fuses and connections first.

 

[blynch]

Great success, it appears to have been either a bad fuse or bad connection to the fuse block. Thanks for all the suggestions, clearly any electrical work is new to me!