Anybody with a schematic and instructions for modifying a TL-922 to use GI-46B instead of 3-500Z wants to share his knowledge? Thank you, 73 W2EOS
Eastern European amateurs performed that conversion a decade ago (2010), BUT that approach required fabrication experience. James Ball, KK4NOZ in Dadeville, Alabama has been promoting this conversion with various parts sold on eBay.
No offense intended, but I'd think hard on this. The ole 3-500z sure is hard to beat on filament life and IMD compared to that Ruskie Tube. If you want a project, then why not just home brew the entire project from the foot pads to the top cover?
Well I don't think they're really that expensive . . . especially as they seem to last MUCH longer than valves like 572Bs. I used to need to replace the 572Bs in my last amplifier about every 10 years. However my TL922 still has the original Eimac 3-500Zs . . . and still gives full output ! As others have posted, these valves were used in numerous Broadcast transmitters, in continuous use for years on end. Roger G3YRO
I can purchase two GI-46Bs for half of the price of one 3-500Z, plus conversion time, sockets, etc. Looking for guidelines and schematics for a conversion from 3-500z tubes to the GI-46B I saw videos on you tube and thought it might be fun to do it to a SB-220 or Amp Supply LK-500. There were only videos, and I cannot find any paper work on the conversion. I am led to believe the GI-46Bs are more robust.
Use the tube curves to build an amp from scratch. https://frank.pocnet.net/sheets/018/g/GI46B.pdf Chopping up an existing amplifier that works seems rather ridiculous. Pheel
