The PHILCO Phorum

Okay, boys and girls, here we go with another exciting chapter of Ron's Radio Rectifications (the actual byline used by Antique Radio Classified years ago with articles I wrote for them).

This time in Handyman Corner, we have a Hammarlund HQ-129-X.

The backstory...

Earlier this summer, I had decided that this should be the year that I finally get a longwire antenna put up. It helped matters greatly that my son-in-law volunteered to do the work for me. About that time, I started thinking about what might be a really good shortwave receiver to use with the new longwire.

For some reason, Hammarlund came to mind. I really don't know why. Maybe because, in 45 years in the radio hobby, I had never owned a Hammarlund prior to this year.

I had an HQ-180 as my goal, but when the opportunity presented itself to purchase an HQ-129-X at Radiofest 2019 (Addison, Illinois) for what I thought was a very reasonable price, I did not hesitate. I brought the HQ-129-X home with me from Radiofest, although it took a side trip to Galena, Illinois and ultimately Clear Lake, Iowa before we headed home.

So...the radio as it looked when I bought it at Radiofest:

[attachment=19953]

I did not care much for the non-original Dakaware knobs, and soon replaced them with knobs that looked more like the originals - not exactly the same, but closer:

[attachment=19954]

These chicken head knobs have slightly rounded ends, sort of like the original knobs. The tuning and band spread knobs are like those used on the HQ-180 and similar Hammarlund sets, but still better looking than the Dakaware knobs.

Click on the image below to see a full sized image of the schematic for this radio (WARNING: 6.2 MB download).

Yesterday, I pulled the chassis out of the cabinet.

[attachment=19955]

Turning it upside down, I wasn't sure what I would find...

[attachment=19956]

As you can see, most - not all, but most - of the original paper capacitors have been replaced with new yellow film caps. The quality of the cap replacements is not quite to my liking, but I may leave most if not all of them alone.

There are some issues I will need to address, though:

[attachment=19957]

I don't care for how the original twist-lock electrolytic was replaced by individual electrolytics with some masking tape wrapped around them. These will be replaced with another twist-lock unit. I considered buying a new twist-lock from AES, but have since decided to open up a twist-lock from the junkpile and restuff it with new Nichicon electrolytics.

[attachment=19958]

Left side of chassis, looking at the bottom: No less than seven original paper capacitors which were not replaced. I will replace them. Since the vast majority of capacitors were replaced with yellow film and the originals discarded, I will not restuff these either.

[attachment=19959]

Back of chassis under speaker terminals: Two more original paper capacitors. One of those, .05 uF, is connected between one side of the line and ground! It will be replaced with a new .01 uF X-Y safety cap. The other will be replaced with a new .047 uF yellow film capacitor.

Additionally, I noticed that R54, which is supposed to be 4K at 5 watts, was replaced with a 10K, 10W unit. That will reduce the B+ to the screen grids of the front end tubes as well as the first and second IF amplifiers. It will be replaced with a new 4K, 10 watt resistor which I just happen to have on hand.

Also, it appears to have its original rubber power cord which is cracking. It will receive a brand new black power cord.

All of the tubes are good save two: the 6K8GT which is marginal, and the 0C3 voltage regulator tube which my tester won't test. Its base is very loose so I'll just replace it anyway.

That looks like a nice radio to restore.  Are all Hammarlunds that un-cluttered?

I don't know, this is the first Hammarlund to ever cross my workbench. But I suspect they are all made in a similar manner.

While I haven't posted anything on this subject in a few days, I am still working on the HQ-129-X.

All of the original paper capacitors which had not been replaced now have been.

As for the yellow film caps, I know that I said (in post #2 above) that I may leave most if not all of them alone. But, being the perfectionist that I am, I could not just leave that sloppy work alone. So I'm redoing them. I have to anyway, as I am also replacing all of the resistors. I am reusing as many of the yellow film caps as I can.

I also replaced the volume control. It had been replaced before with an obvious junkbox part. It now has a brand new 250K audio taper control with switch, from Radio Daze. Now that switch snaps on and off as it should.

Photos tomorrow. There is a lot more work remaining to be done on this set, too.

Sounds like you are having fun Ron. Good on ya!

cheers

Thanks John.

Progress:

[attachment=20024]

I've removed and reattached most of the yellow film caps now, and have tried to do a neater job. I have also replaced most of the resistors.

New caps replacing old:

[attachment=20025]

[attachment=20026]

more...

At the 6H6 (2nd detector) tube socket.

Before:

[attachment=20027]

After (by the way, the ceramic discs are 100 pF, NP0):

[attachment=20028]

New volume control with power switch, 250K, audio taper:

[attachment=20029]

Now I'm waiting on a couple tubes from Bob Dobush (findatube.com) and some resistors from Mouser, so that I can hopefully wrap this up.

Work will continue after I get over the next chemo session...in about a week and a half.

Too bad you didn't look on eBay. You can buy complete NIB tube sets for Hammarlunds on there. I have bought sets for both of mine. Here is a link to the one for yours. https://www.ebay.com/itm/NIB-tube-set-fo...SwEetV7e3l

I did see those on the auction site recently.

Why do I want to spend $73 when only one tube was (possibly) bad and one marginal? So I only ordered the two I needed from Bob since the rest are still good.

Dobush is a good source and easy to work with, his wife answers often and is a peach. 

That underside looks real clean. You will have a fine receiver, bet you can get WBZ from Boston, AM 1030  with that one. 

Paul

I understand, Ron. I just like to have a full extra set for all of my radios. You should see the shelves full of tubes I have collected over the years, all tested and boxed. LOL ! hope when I'm gone nobody is stupid and throws them out. They could bring some money on eBay.

Ron, those were some pretty ugly (and possibly cold) solder joints before, nice job cleaning them up!

Looking good Ron, I am enjoying following along with your progress.

Didn't I see that you also bought a second communications receive (or am I perhaps mistaken) ?

Back to work on the HQ-129-X.

Remember the mess that was the set's electrolytic capacitors? If not, here's a reminder.

[attachment=20105]

Thursday evening, I returned to the workbench and decided to prepare an old twist-lock capacitor I had found in the junkbox.

[attachment=20106]

I cut off the aluminum at the bottom end and carefully disassembled the unit.

Then I installed three new Nichicon 10 uF, 500V electrolytics I had bought just for this purpose.

Soon, I had it all together again:

[attachment=20107]

All restuffed, reassembled and ready to go where the original electrolytic once was mounted. The original was a four section unit, also containing a 20 uF, 25V electrolytic. Since the twist-lock electrolytic can I found only has three terminals, I will install a new 20 uF electrolytic direct between the output tube cathode and ground.

more...