| PM | Quote | Reply | Full Topic |
Joined: Fri Nov 10th, 2017
Posts: 57
Status:
Offline
Reputation: 
Reputation Points: $user_rep
I set this radio up as a "temporary" installation, but after five years and 70k miles I guess I should probably admit it's not likely to change any...
Uniden 68 radio, barefoot/stock outta the box. Mag-mount Wilson 1000 with a short load whip on the roof, cable routed as best I could to avoid loops. Had the SWRs somewhere reasonable when I first installed it. I forget now just what they were, but under 2 on all channels.
I often unscrew the whip and leave it on the dash (so I can get into the parking garage at work, the carwash, etc.) and sometimes leave it there for months at a time, as I don't actually use the radio much. This is probably rough on the coil, bouncing around on dirt roads and such.
Put a fiberglass topper on the truck over the summer, and figured I should check my SWRs again. Pegged the meter on every channel.
I'm definitely not an electrical engineer- antennas confuse me. But I did a little quick research online and found some simple checks- continuity from center-to-center, and outer-to-outer on the coax from the radio end to the mag-mount base; open between the center and outer of the coax. Continuity from center to outer at the base of the antenna coil (which surprised me, but my research suggests is correct).
A friend suggested laying some sheetmetal over the cap to make sure it wasn't a ground-plane issue; still pegged the meter.
I'm leaning toward a vibration-related failure in the antenna coil...anybody got any ideas before I pry the thing open for a look-see? (I'm not entirely sure it'll ever go back together, so I'd like to be fairly certain that's where the issue is before I start.)
No telling, I don't suppose...but I don't believe I've keyed the mic since this issue developed (beyond for the meter) so I think the radio should be OK.