Olson RA524 tube FM receiver
 

I have been working on an Olson RA524 tube FM stereo tuner and the AM214 stereo tube amplifier (uses 2 12ax7 and 4 6BM8 tubes) - anyone have any schematics or other info on these units? I have asked on the audiokarma site already but there doesn't seem to be a whole lot of info on these units.

Thanks
Rick

Were these sold by Olson electronics in western NY or Ohio?
It looks like Sams covered some models in the early 60s, but AM214 was not listed.
Ill look up the other number, maybe its close. Those tube #s help a lot.

Often you can guess. The four 6BM8 tubes are the output and drivers for two push pull amplifiers, and the 12AX7s are phono preamplifier and input amplifiers.

Olson was not high end so the tuner probably is pretty basic, with 6AU6 and/or 6BA6 tubes and a 12AT7 FM front end and a 6BE6 AM converter and maybe a 6AL5 or silicon/germanium diode detector. If it's stereo you also have the decoder section.

Just stare at it for a while and it should make some sense.

Just judging by that tube lineup and the fact that it's Olson branded probably means that both the amp and tuner are of Japanese origin. Olson re-branded a lot of stuff made by Pioneer and Trio-Kenwood in the 60's. Could you post a photo of the units, and possibly one underneath the chassis?

If the units are Japanese than ALL of the capacitors will need to be replaced. Japanese manufacturers used gray tubular ELNA or Suzuki oil filled capacitors that seem to have about a 100% failure rate with age. The either go leaky or dead short. I've never had a japanese made tube Hi-Fi component that worked on it's original nonpolar oil caps. The electrolytic filter cans are sometimes a different story. I've had a couple of Pioneer tube receivers and a couple of Olson re-branded Trio-Kenwood FM tuners. Both needed a full recap but worked perfectly after I took care of that.

Its definitely a Japanese unit, I found a few date codes of 1959-7 on some larger caps.

I have already replaced all the "paper in oil" caps, the electrolytics and awaiting a shipment for the remaining few non tubular caps and the parts for the RA524 receiver. The amp was working pretty well after the partial recap but it lost a channel somewhere before the power amp section (power amp works fine on both channels) which I am now trying to track down - hopefully its one of them I haven't replaced yet. Thanks for the info.

Not sure where they were purchased but since my family is in Western NY and it was my grandfather's equipment it could have come from a local retailer - apparently they were headquartered in Akron Ohio from what I dug up so far.

Attachment 181297

Took advantage of the snow day and the cap order I received yesterday to finish the recap on the AM-214 amp (and fix the channel 2 issue I had) and do the RA-524 FM receiver. Both seem to be working fine after the surgery :music:

Any suggestions for the oxidation or whatever the dark areas are on the amp's face?

Yup, that combo looks very Trio-Kenwood to me.
http://i.imgur.com/LRTuE8Il.jpg
You could try a VERY gentle cleaning with some Mother's Mag and Aluminum Polish, followed by a coat of clear spray lacquer to keep the panel from oxidizing again. It's worked for me with old gold tone face-plates before.

Thanks for the suggestion, will give it a try...

From some digging it seems the same as or very similar to the Monarch SA-40 and probably a few others of that era. Would still like to find a schematic for it but with the recap it should work well for a while.

Those oil caps are almost certainly going to contain PCBs, so if they leak, don't get any on ya.