The HQ-100 manual conveniently provides a table of the voltages you should be seeing at the tube pins. After replacing three of the tubes in the HQ-100, I went through and checked all the tube pin voltages and ended up replacing two more tubes (the 6BE6 and 6AL5 tubes). I didn’t have a spare 6AL5 tube on hand, but I discovered the VoltOhmyst VOM I acquired a while back also happened to use a 6AL5 tube. After pulling it out of the VoltOhmyst and putting it into the HQ-100, all the voltages at the tube pins matched the voltages in the table.
Unfortunately, I’m still not hearing any static or audio from the radio, so there’s more work to be done. The realignment procedure described in the manual calls for a 455 kHz signal source, so the next task will be to get one set up.
Update 02-Apr-2023: Since I had them on hand, I replaced the 6C4, 6BZ6, OB2, and 5Y3GT tubes. Now the only tube that hasn’t been replaced is the 6AQ5.
The HQ-100 has some new Class X2/Y1 capacitors across the AC input, a polarized two-prong power cord, a new multi-section can capacitor from Hayseed Hamfest, and now three “new” tubes.
New capacitors installed in the Hammarlund HQ-100
After spending a few days checking over things, I put the front panel and knobs back on, plugged the radio in and was greeted with some warm glowing lights.
Hammarlund HQ-100 plugged in and showing some nice glowing lights.
The two lamps behind the frequency dial indicator both came on, and a nice warm red glow was coming from most of the tubes. Three of them (a 12AX7 and two 6BA6s) were dark though. Fortunately I had acquired all the tubes I needed for the HQ-100 at past hamfests. After replacing the three tube and applying power again, all the tubes were lighting up!
Replacement tubes lighting up
Next step will be to attach a speaker and antenna and see how well, if at all, the radio receives.
At long last, the Hammarlund HQ-100 I picked up a few years ago is finally getting some time and attention on the workbench.
Hammarlund HQ-100 receiver
After a bit of cleaning outside, it was time to dig in and see what was going on. Removing the knobs and four slightly rusty screws let me remove the front panel to see if the band spread tuning dial could be fixed.
Exposed tuning frequency indicator dials after removing the Hammarlund HQ-100 face plate
Turns out the frequency indicator dials (the large white disks) are connected to the tuning dial knob by friction fit. Turning the knob makes the indicator dials turn, and the shaft those dials are attached to are connected to the variable capacitors that do the tuning. The band spread dial was free-spinning because there wasn’t enough friction between the indicator dial and the tuning knob. While I was trying to figure out how to fix it, I discovered the nut at the back end of the tuning shaft was loose, and tightening that up made the tuning knob work again.
The other big issue I came across while looking around was a burnt capacitor across the AC input.
Burnt capacitor on the AC inputBurnt 0.01 uF capacitorAC filtering caps
Not a good thing to see. I clipped the toasted capacitor out as well as the old two-prong non-polarized plug. I’ll see about wiring in a new three-prong plug and maybe a fuse as well.
Haven’t seen any other obvious component issues yet. There’s a multi-section electrolytic can capacitor that probably should be replaced, but there aren’t any signs of leakage.
One of the items in the KB4NNM (SK) collection that was donated to the club earlier this year was an Atlas 210X 5-band HF radio mounted in a 220-CS AC console. The console allows the radio to be operated off mains power, provides a speaker and VOX capabilities.
Atlas 210X mounted in a 220-CS AC console
It’s a pretty nice looking setup. Until I did a bit of research on the radio, I didn’t realize that the radio and console were separate items. Turns out, the radio just slides into the console, and connects using some 1/4″ plugs and a banana jack-like connector for the antenna.
Atlas 210X removed from the console
Sounds like the radio works, although the speaker produces a buzzing noise (60Hz hum I think) even when the radio’s AF gain is turned all the way down. Turning some of the dials and switches produces some static-y noises, so it sounds like those will need some cleaning. Haven’t had a look inside the radio yet. That will be later.
This seems like it might be a nice radio to use in the club room.
Every now and then, as president of the local amateur radio club, I’ll get an email from someone looking to donate radio gear to the club so that it can be put to use by someone. I usually arrange for myself or one of the other club members to go pick up the gear, and we’ll check it out. We’re always appreciative of donations like this and usually the equipment ends up with new hams starting out in the hobby.
The most recent email I received a few days ago didn’t say what kind of equipment it was and when I arrived to pick up the gear, I was quite surprised. The equipment donated by the family turned out to be not amateur radio gear, but two sets of old surplus US Navy communications equipment dating back to 1944 and 1945. Pretty cool museum pieces.
There were also a couple of old CB radios and some mag mount antennas but compared to the main haul, they seemed somewhat incidental.
Some unexpected equipment
On the outside they’re not in the greatest shape, and appear to have been sitting around in storage for at least a few decades. Most of the pieces had lots of built up dirt and dust, and a lot of flaking paint. And they were heavy.
Each set has a transmitter, receiver, power unit, antenna loading coil, and remote control unit. All of them look like they might have been cannibalized for parts at some point.
An instruction manual even came with the collection, luckily enough. Should be helpful with the restoration.
Model TCS-13 instruction book
The power rectifier units were the heaviest of all the units, and each of them appeared to have had a few parts repurposed from them.
They’ve definitely seen better days.
I kind of doubt they can be restored to operating condition, but I think at least one set can be cleaned up enough to use as a display piece, maybe for the club room. I’ll have to see if there are any club members interested in restoring boat anchor gear who might want to make a club project out of this. Should be a fun project to work on.
