The AM Forum

Have you ever felt so sorry for a radio, that you had to buy it because of its abuse? Well that happened at Nearfester when I saw this little Ameco TX-86 that was literally eaten through with rust on one side. It was ridiculous looking, but I bought it for a donation of 10 dollars.

After I pried the perforated box off the front panel, which was a tough enough job, I saw that there was surface rust on most of the the inside chassis. Also, ALL of the tubes were smoky. All gassy - not one good tube. Where the hell had this thing been stored? It takes a lot to penetrate the vacuum seal of tubes. My guess is that it took years of wet and fantastic temperature extremes to accomplish this. So the old Naval Jelly and wire brush came out in force. Some of the fasteners simply broke, they were so bad.

The refinishing was a lot of work. I used black crackle on the outside perforated box and copper spray paint to touch up the copper plated front panel that was missing copper in places.
Then after quite a bit of sleuthing work (worst schematic ever drawn by a supposedly professional company), some rewiring and undoing mods, some parts replacement like all electrolytics, and a fresh set of tubes - My lord it puts out clean CW on all bands. Even with my command set power supply which is a bit low in recommended voltages, it does 35 Watts out. It has an extra stage that provides plenty of drive for the 8552 (6883B) (8032A) 12V mobile version 6146B final.

I have not tried AM yet. It has a primitive screen modulator.   

The line up is a 12BY7 Oscillator multiplier, 6BQ5 Driver (way overkill probably so it works on 6M!), 8552 Final, 12AX7 speech, and 12AQ5 modulator. It also can be wired for 6V if you substitute a 6146 final and 6AQ5 modulator. They play games with the fils to retain the 6BQ5 in either configuration and I will let you figure that cleverness out.

Some Ameco Pics. My 220V/ 500V supply does not give the unit the 300V and 600V it wants for full power. I manage 30W on 80M and 35W on 40-20 M.

I am glad you saved it as they are great little SG rigs.


Phil - AC0OB

very nice Restoration, congratulations!!

Once, but didn't exactly buy it IIRC or maybe it was $5 or something. A ham was angry at not getting his price or whatever on the model 122 optional external VFO for the Viking I/II. He tied it to the back of his car and dragged it all the way to the gate. One of the volunteer persons stopped him at the gate (thinking it was not intentional). I was close by and had watched this pass by like about 100 other people, and asked the guy if I could have what was left of it. I cut it loose and he roared out the gate like a madman. After a new cord the beat-to-heck VFO went to some guy with an ugly old Viking I had. Everyone was happy. The VFO still worked!

Wonderful job Mike.  It just goes to show that with enough passion, pretty much anything can be brought back to working condition.  Its good to hear the performance is equally as good.  Now what about that waxed cap under the tuning control  ;D. 

Joe-GMS   

How did you bring back the black lettering so well?

   Awesome restoration.  I haven't seen a schematic for the TX-86, but I think it uses the same "Ameco Duo-Grid" modulation scheme as my TX-62, where they use a clamp-tube to shunt modulate both the screen and control grid.  I get good audio reports on my TX-62, though not quite as good as some of my other rigs.  Might be able to improve on that a bit, though.
    Tell me - my TX-62 is the first Ameco rig I've owned - does the panel meter on your TX-86 do a bobble-head imitation whenever it reads?  Whenever the needle on my TX-62 moves, it does a boing-boing-boing back and forth bounce for about 2 seconds before settling down.  Freaked me out when I first keyed it up, and I un-keyed immediately figuring something was going massively monkey poop.  Doesn't appear to be anything electronic, just a lack of mechanical damping, since it does the same thing when entirely un-powered if I rock the rig back and forth.

Whoa I just got rid of the rust as best I could, spray tanned it with copper paint and used a sharpie! Pretty weak "restoration" on the cosmetics and lettering. But at least you can read it!
Next - we shall see if it does AM.