[Amps] Price Help

[Tom W8JI]

> Our club will have several 4-1000A and 4-400 tubes for 
> sale at the
> convention this weekend. All pass an ohmeter test for 
> filament continuity
> and no element shorts. What would be a reasonable price 
> for each type
> assuming appearance shows little use to obvious usage? 
> Used B and W 30amp
> fil choke?
> Tnx, Dan, N5AR

Dan,

Tubes are worth whatever you can get for them.

Myself, I'd be very reluctant to pay anything for an as-is 
power grid glass tube without knowing for sure it runs. The 
reason is the seals always leak some air, especially if the 
tubes have been used or if they are in a humid environment.

Years ago I was at Dayton with a friend, and he bought a 
pair of  unused 3-400Z tubes from a guy. I bought two the 
same fellow said were just pulled from operation. The tubes 
had the same date code, they were 5 or so years old.

His unused tubes were both so gassy they were unrecoverable. 
The used tubes with slight envelope discoloration were 
perfectly good. The difference was for several years the new 
tubes slowly gathered air, while the used tubes were 
operated and the zirchronium getter on the anodes did its 
job keeping them gas free.

So again the fair thing to do is make it clear they are 
untested, and just take whatever you can get. How they look, 
unless something you can see is broken or melted, has little 
to do with if they actually will work.

73 Tom