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GregTJ

New member
Joined
Apr 10, 2023
Messages
1
Location
Montana
Hello everyone!

I'm a lifelong electronics hobbyist from the beautiful state of Montana.
I'm pretty knowledgeable on the subject of modern electronics design, both due to my interest in the subject, and due to my previous job as an alarms / controls / comms tech.
However, I've only just delved into the world of vacuum tubes.

Recently, I helped price an estate sale for a woman whose husband was an EE, ran a RadioShack, had a band, and designed his own audio equipment.
Sadly, despite being quite brilliant, he can no longer continue his work due to worsening dementia.
I bought most of his vacuum tubes, some misc. audio components (mostly transformers), and a good-condition Hickok 539b with a Compactron adapter that appears unused.

I've gone through 100+ tubes, screening them with the tester, and trying to decide what I should hold on to.
The picture I attached is about half of them! (FYI, a lot of them were stored in random boxes, so many of the visible labels are incorrect.)
I'm also working on testing the transformers with my scope / network analyzer.

I've found some gems; a pair of USA Made Tung-Sol 6550s, five 45° getter German Telefunken 12AT7s, some GE 7199s, a pair of RCA 7025s, etc.
I've also found some funny ones; four "Amperex" 6AS7Gs with plainly visible Russian UFO getters, some "7025" tubes with type codes that suggest lowly 12AX7s, etc.
If I could keep it all, I would, but money is tight as always, so I sold some of the especially sought-after components like the 7199s.

So far, I've set aside the following for circuit design and experimentation:
  • Fifteen ProComm-rebranded Sovtek 12AX7s (they didn't even try to cover the old logos haha)
  • A few magic-eye tubes
  • Four tightly-matched, presumably NOS, GE 6973s
  • Five Fender Special Design 6V6GTAs
  • All of the misc. low-value radio and TV tubes
  • Adding more as I go...
I'm kicking myself for selling the 7199s after finding an amp circuit in an old RCA publication that calls for a them in combination with 6973s.

TLDR:
I'm happy to be here and excited to get started with some tube-based projects!
I've been dreaming up a 12AX7 astable multivibrator based synth with digital / midi input.
Before I can tackle that, I need to finish the Li-ion powered coupled-stage boost converter I'm designing for prototyping HV circuits.

- Greg
 

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