The Cranky Sysadmin A world of technology, fun, and ignorant rants.

June 30, 2013

Don’t Disturb the Dust!

Filed under: Electronics,ham radio — Cranky Sysadmin @ 11:39 am

My Heathkit® project took a turn for the worse yesterday. There was some occasional arcing in the audio section when I turned on the radio. The cause seemed to be the sediment on the board. Do you know that feeling you get when you’re about to do something bad? Yeah, I’ve discussed this before, and I ignored that feeling again. Instead of taking the safe and lazy route of tracing down where the arcing was coming from, I decided now was a good time to lift the audio board out and clean it up. As the dear reader might predict, the audio section is now non-functional. I’m pretty sure things are wired up correctly. My current suspicion after triple-checking the wiring is that I disturbed some marginal component enough to stop it from working. I’ll have to look at after I complete some other easy projects that have been languishing, like my solar charging station and short vertical antenna.

June 25, 2013

The Tubes All Light Up. It Must Be A-OK

Filed under: Electronics,ham radio — Cranky Sysadmin @ 7:27 pm

After the great HW-100 conflagration of 2013, I figured I’d proceed with more caution in powering up the radio. I rewired the power cable, then looked over the HW-100. I replaced the electrolytic caps, and I found the source of the loud pop during my initial test. Fortunately, it was just what looked like solder dust on the audio board. I cleaned the boards up as good as I could without tearing it down. I then proceeded to power up with care. All of the tubes light up, and there is no smell of burning electronics. I plugged in a pair of head phones and tuned around. The radio appears to receive on all bands though it seems a little deaf on 20 meters. I am so glad I didn’t burn up anything obvious. Tomorrow, I will start the alignment process.

June 24, 2013

Hard Lessons About Old Heathkit® Gear

Filed under: Electronics,ham radio — Cranky Sysadmin @ 8:26 pm

I recently purchased an old (possibly older than me) Heathkit® HW-100 transceiver and a HP-23 (the “first edition”). After getting it home, I immediately proceeded to plug it in and test it. You know that nagging feeling you get when you’re doing something you shouldn’t? Well, I ignored that. When I plugged in the supply, the fuse popped. I took a look inside. It was wired wrong in several ways. While I spent time rewiring it, I noticed that the electrolytic caps were light as a feather. I replaced those and tested the power supply with much better success. Don’t trust the ebay add that states “tested good”.

I then proceeded to plug in the 11 pin cable to the power supply and the HW-100. You know that nagging feeling you get when you’re doing something you shouldn’t? Well, I ignored it again. I powered up the radio. There was a loud pop in the radio and one of the audio tubes glowed white hot. By now you see the pattern of my misdeeds. It turns out that the cable is wired completely incorrectly for an HW-100. It almost looks like it’s mostly wired partially backward.

Well, once I fix the cable, I’m going to give the HW-100 a good going over. The ebay sale listed a litany of problems which looked fixable. Now it has at least one more problem. I hope I have the tubes and components to fix my mistake.

June 12, 2013

Arduino Capacitive Touch Iambic Key (using attiny85)

Filed under: Arduino,Electronics,ham radio — Cranky Sysadmin @ 9:19 pm

Since I’m trying to learn morse code, I decided I’d build a key which functions as a trainer and an actual key. I’ve always liked the idea of capacitive touch sensors, so I went with that. This is a small project using a handful of parts. One should be able to finish it in an evening of focused work. Read on if you’re interested in the details.
Iambic key details

June 9, 2013

A Field Day Antenna for 80 Meters part 2

Filed under: ham radio — Cranky Sysadmin @ 2:32 pm

I’ve made some progress on my short vertical for 80 meters. I put it up in the air and added the guy wires. Some pictures and commentary are after the fold.
The Fold

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