4-400 Johnson Thunderbolt Amp.

Let others help you to determine what a piece of equipment is worth, before you put it up for sale.
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Joined: Sat Nov 25, 2023 7:00 pm

4-400 Johnson Thunderbolt Amp.

Post by ka9ucn »

4-400 pulls last rotated in a Johnson Thunderbolt around 10 years ago. (4pcs.)
Old Johnson Thunderbolt amp. It is very rough but worked well 10 years ago. It should be considered a parts project amp.
Should I sell the tubes and amp together?
The amp has no inductor in the B+. It has been converted to capacitive filtering with solid state rectifiers.
Posts: 10
Joined: Fri Sep 02, 2016 9:42 pm

Re: 4-400 Johnson Thunderbolt Amp.

Post by ah7i »

I like the Thunderbolt and own one!

Take it to a hamfest. Take the first cash offer you get, as-is.

Be done with it!

Paid $100 for mine in nice looking condition with goid tubes and bad choke. That power transformer will overheat and die if given any serious on time with a C input filter. It really needs original choke and cap values if it's gonna be used a lot.

If you don't care about the time and parts scrounging... get it running, add some relays and PTT keying, and trade it locally for about $250.

73, -bob
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