After last week’s meeting, Al, KC8RNQ came up to me and asked me if I could help him troubleshoot a problem with one of his rigs, a Kenwood all-mode, 2m radio. I asked him what was wrong, and he told me that it would “cut out” intermittently and that someone he was talking to thought it was “just” a bad connection in the microphone. Furthermore, the reason he wanted to fix this was so that he could give the radio to a new club member (and recent Tech licensee) who did not yet have a rig.
Well, I certainly couldn’t turn him down, especially after he said he was going to give the radio away. So, I told him to come over one evening the following week.
Tuesday evening Al brought the radio over, and we plugged it in and started playing with it. Sure enough, it worked great for a while, then nothing. Pushing on the mike cable, I was able to get it to transmit, and to transmit repeatably, so it did indeed look like “just” a bad connection in the microphone connector.
I say “just” because there is, of course, more to any repair than at first meets the eye. The first problem we encountered was disassembling the connector in the first place. I removed the strain relief and the set screw, but the connector still wouldn’t pull apart. It took us about 15 minutes to figure out that you had to unscrew the plastic part from the metal shell.
Once we were past that hurdle, the fun began. After poking each of the wires, it looked as though the mike element ground wire was the loose wire, and that all I had to do was add some more solder. But of course that didn’t work, so we decided to start from scratch.
We cut all of the wires and then removed as much of the solder as we could from the connector’s four solder cups. Next, I stripped back some of the cable jacket, and stripped the three wires with insulation. (The fourth conductor was a stranded, bare-wire shield around the mike wire.)
At that point, it hit me that I hadn’t written down which wires went to which contacts. Fortunately, I remembered that the push-to-talk (PTT) switch connect to the two contacts opposite the connector’s key. Then, using a needle nose pliers, I was able to figure out which contact was ground by alternately grounding the two contacts. The one that caused the radio to transmit had to be the contact for the white wire.
Having figured that out, it was back to soldering the wires back to the connector. I had already stripped the wires, but each had some fiber inside it that had to be cut off before I could tin the wires. At this point, I had to put on my reading glasses so I could see the fine strands to cut them off.
Finally, after getting the wires tinned, I started soldering them to the connector. I got two of them soldered and was starting on the third, when I made a bad mistake. I trimmed one of the two remaining wires too short. No amount of pulling and prodding would get it to where I wanted it, so I had to cut the two wires I’d already soldered and start all over again.
All this wouldn’t have been so bad, but for all the harassment I was getting from Al. He wondered how this “simple” repair could have already taken me more than an hour to complete. I can’t complain too much, though. He did help by holding the connector as I was soldering the wires to it, risking burnt fingers every time I brought the soldering iron close to the connector.
Finally, nearly two hours after we’d started, I got everything back together again. If I was running a radio repair shop, I could have perhaps charged $10-15 bucks for that repair. That’s why I say I guess that a career in electronics service is out for me.
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