The Amateur Amateur: Radio Repair

By Gary Ross Hoffman, KB0H
September 2015

Transceivers at Christian Hospital

The Amateur Radio transceivers at Christian Hospital. One works and the other... well....

Stop. Before you begin reading this with the expectation that I performed some miraculous radio repair, I didn't. I'm not that kind of Amateur Radio operator. I have only a rudimentary understanding of electronics, and circuit diagrams containing more than two elements baffle me. So be forewarned, this is not a highly technical story. The words "oscilloscope" and "signal analyzer" will not appear anywhere in it.

Alright, I'm not completely clueless. It's impossible for me to have been a ham for twenty years and have not picked up something. I have managed, on rare occasions, to actually fix something electronic, even a transceiver. These repairs weren't complicated, though, and only involved easily accessible and clearly faulty components. But I am nothing if not adventurous. I make a lot of mistakes, but I keep on learning. And it has been years since I set my car on fire1.

Here in the St. Louis area we have an organization called the Hospital Amateur Radio Network (HARN). It covers several counties in both Missouri and Illinois, so it doesn't neatly fit into an ARES or RACES footprint. It does, however, fully cooperate with both organizations. For that matter, it's much the same group of Amateur Radio operators.

Anyway, HARN holds a monthly radio net. The net controller calls each hospital scheduled to test its radio, and if an operator is present he or she responds. This is followed by a similar test run by the Warren County Emergency Management Agency, and then two HF nets (75 m and 40 m) run from the Department of Health and Senior Services in the state capitol of Jefferson City, Missouri.

That is a busy morning here at the Hoffman household. I get ready and head out to the St. Louis County Department of Health to test its radios. Simultaneously, my wife Nancy, N0NJ, heads in the opposite direction to test the radios at nearby Christian Hospital.

disconnected wires

Someone's been messing with the wires. And where is the power plug?

This August Nancy and I both departed for our assigned locations. Once I got to the Department of Health I did a quick check of the radios, then pulled out the various logs I would need to fill in, and also the script for the HARN net (lately I've also been serving as the net controller). As some hospitals do not test their radios every month, I checked the list of which ones would be participating that day.

At 0810 local time I started the net. When I got to the roll call I was not particularly surprised that a few of the scheduled hospitals did not check in. Sometimes the Amateur Radio operator simply can't make it. I was very surprised, though, when Christian Hospital did not respond. Nancy should be there. She left at the same time I did.

Well, I didn't worry too much. The radio could have failed. And in any case, I had logs to complete and several more nets in which I was supposed to participate. It was only after I left the Department of Health that my imagination started to run wild.

Christian Hospital had two radios, one ostensibly for packet, but not yet set up that way. Many of the hospitals had the same configuration, and the operators would usually test both radios during the HARN net. If one had failed, why hadn't Nancy used the other one?

Any number of reasons. The radios were in a conference room. Perhaps there was a meeting.

Or perhaps she had an accident. Or been kidnapped. Or.. or...

You cannot imagine the relief I felt when I pulled into the garage and saw Nancy's car sitting there. I dashed in the house...

...and Nancy quickly explained the problems she'd had. I say "quickly" because she had a doctor's appointment and had to leave immediately.

Gary working on wiring

Me, pretending to be Radio Repair

According to Nancy, one of the transceivers wouldn't power up at all. The other one was receiving okay when she turned it on. They both sit on an end table, which she pulled away from the wall so she could see if there was a problem with the connections. As soon as she did that, the second radio stopped working. The lights were on, but nobody was home. Having no tools and little inclination to make things worse, she filled out her logs and headed back home.

That was exactly the right thing to do.

Once Nancy returned from her appointment, we discussed it further, and then I contacted Steve, KC0QMU, the Amateur Radio Emergency Coordinator for HARN. After several emails with him and with Ryan Pirtle, the Manager of Environmental Safety and Emergency Preparedness at Christian Hospital, we arranged for Nancy and me to meet with Ryan the following Tuesday. I said that it might be something that could be easily fixed and that I would bring my tools.

What I imagined was that a cable had pulled loose on one transceiver and that a button had been bumped on the second transceiver, thus putting it into what I call "weird mode".

Just in case, I added a few more tools to my bag. And some fuses. And in case those fuses didn't fit, some different types of fuses. In the end I took two bags.

Nancy took another. Just in case.

Well, it was a long wait for Ryan, but we forgave him once we saw his bedraggled look and his hard hat. It seemed that he'd been distracted by a sprinkler system that had decided to extinguish a non-existent fire.

We all trooped up to the conference room. I pulled out the table as far as I could (not much leeway on the coaxial cables) and squeezed in behind it (even less leeway on my belly).

Nancy had said that it looked like someone had disconnected the wires leading from one of the power supplies to its transceiver. She was right. More than that, the power supply had been unplugged from the wall outlet. We could only guess why. The suspects were a construction crew that had been working in the room, but why they, or anyone else would start disconnecting things was a mystery.

Nancy at the mic

Nancy testing out my "repairs"

Anyway, this was something that was well within my skill set, so I reconnected everything and the transceiver started working. It was really very simple, but it seemed to amaze both Nancy and Ryan (probably due to all the technical jargon I was spouting while fumbling around back there).

Flush with success, I climbed out from behind the table (my most difficult task so far) and took a look at the second transceiver. It looked okay. It was on the correct frequency. And initially it appeared to be working. It was only after making a slight adjustment to the squelch that I discovered the problem.

The sensitivity was shot. The squelch had to be almost open before the transceiver would pick up anything. I tried a couple of different repeaters and swapped the coaxial cables around and confirmed my diagnosis.

The look on Nancy and Ryan's faces when I told them it was something I couldn't fix indicated that the short-lived adoration I'd earned moments before had just evaporated. Ah well, better to be honest about it.

Looks like we'll have to arrange for a real Radio Repair.


1 - See my October 2001 column Mobile Flambée.

E-mail Gary Ross Hoffman

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