Category Archives: Technical

HQ-110 Repair

I have an Hammarlund HQ-100 I bought several hamfests ago. It is identical to what was my first novice receiver. I had worked a few years ago, but last New Years Eve, when I tried to use it on straight key night, the main power transformer had a meltdown.

It has no fuse, and besides the mess in the radio, the transformer needed to be replaced. Likely the filter caps as well, which may have been the original culprit, not sure. So I tried looking for a drop-in replacement, but could not find one. Some were close, but often were lacking a 5V secondary for the rectifier, or the high voltage was wrong, or the current capacities were off, etc. There also were no used ones for sale.

So I contacted Heyboer in Michigan, and thought I had agreement via email for them to build a new one. I sent them the specs, and didn’t hear back. So after a few weeks I called them, oh, he found my email. Ok, they will build it. 10-12 weeks worst case he said. After about 20 weeks, I emailed them again. No response.

In the meantime, I started cleaning up the radio. Brown gunk from the transformer and smoke were pretty extensive. Tried alcohol, acetone, elbow grease, and I improved it significantly, but could not get it all. While cleaning, I noticed two diodes soldered between a couple of the pins on the rectifier socket. Worse than that, they weren’t soldered on one pin, and on the other pin they didn’t go thru the pin at all, just tacked soldered, and the solder joint was broken. I pulled the 5U4 from the socket, and two pins were cut off, so it was just there for decoration.

I thought about repairing it using solid state diodes, which would eliminate the need for a 5V winding, but still getting high voltage specs matched were a concern. I also contacted a friend who I trust for this kind of info, and he recommended putting it back stock.

About that time, a used HQ-110 transformer came up for sale on eBay. It looked a little rough cosmetically, and it was in Columbia, the country. But the seller had 100% satisfaction rating. So I bought it, and it was less than 1/2 the cost Heyboer was quoting me.

So I’m in the process of rebuilding the power supply section of the radio. I have to replace the 5U4 octal socket, as it was gunked up. I have a new filter cap from Hayseed Hamfest. I think I will put in a 3 wire power cord and fuse. I’m not worried about originality of the power cord.

I need to test the transformer first. Then start the rest of the project. I will update as I progress through it.

Tim Hunkin Videos

Possibly in the 90s you saw the British TV show called “The Secret Life of Machines”. It featured maker and cartoonist Tim Hunkin. I hadn’t seen anything about him in years, but he recently started a YouTube channel and started a new series of videos called “The Secret Life of Components”.

Though not ham radio specific, it discusses many things that still may be of interest. Six have been released and they are still being released about 1 per week. Prominently featured are his hand-built arcade/novelty machines.

His Secret Life of Machines shows have been remastered for his YouTube channel.

Though some of the topics might seem elementary, I find I learn something in every episode.

Here is the link to his channel, give it a try:
https://www.youtube.com/c/timhunkin1/featured

Troubleshooting a FT-1000MP Loss of Receive Problem

A YouTube Channel I watch regularly. This is a good example of one of his typical videos. He is German, speaking in English, and it is a bit slow moving at times. I usually speed it up to 1.25 X normal speed. This is an excellent example of his methodical troubleshooting techniques to narrow down the problem – even on a modern type radio. No real special equipment used in this video. A multimeter is the main tool, but a signal generator is used, and a scope briefly, but really not necessary.

Maybe you might find it interesting.

FT8

You might have read about a new digital mode in QST this month.  Apparently it was part of a pre-release version of WSJT-X, but it is already in wide use.  If you saw our program on JT65 last fall, or have used JT65, this is very similar.  In JT65 each exchange is 1 minute, and a full QSO takes 5 minutes.  In FT8, an exchange is 15 seconds, and a QSO takes about 1 minute and 15 seconds or 1 1/2 minutes.

JT65 obviously allows contacts with weaker stations, but FT8 is substantially quicker to complete a QSO.

Because of the minimal time allowed between decoding a transmission a the start of the next one (2 seconds), FT8 usually requires auto-sequencing of the standard exchanges.  This makes the QSO almost automated (except for choosing the station to contact or calling CQ).

This might make FT8 more fun, or less fun, depending on your point-of-view.

If JT65 was boring for you because of the length of each transmission, FT8 is a mode you might want to try.

Search WSJT-X, and download the latest version (currently a version 1.8 Release candidate.  The released version doesn’t have FT8)

YouTube Channels for Radio/Electronics Repair

Here are some of my favorite channels:

Mr. Carlson’s Lab

Mr. Carlson is VE7ZWZ.  He has an amazing shop full of test equipment.  It seems like his videos are intended for a wide audience, so depending on your point of view, it may be too basic or too advanced.  But most people will probably learn something.

D-Lab Electronics

Terry Dayton N6TLU specializes in tube equipment, either vintage guitar amplifiers or ham equipment.  Good info on restoring and troubleshooting.

TRX Bench

I’m s sorry I don’t know who this is.  His videos are mostly repair of ham radio gear.  He sounds German, or from that area of Europe.  His English is very good.  The videos are fairly slow paced but quite thorough.  His explanations of his troubleshooting strategies is excellent.

W2AEW

A wide variety of topics.  Repair, tutorials, test equipment.  Some great stuff.

The Radio Shop

Another channel with a bunch of ham radio repair videos.

Uncle Doug

Not really any ham radio content, but vintage electronics stuff. Mostly guitar and audio tube amplifiers.

EEVBlog

Lots of general electronics stuff for a hobbyist.