RE: Testing 833A's

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Dave,
Please forward a copy to me as well. My tube coil is the project I'll play
with when I can't move the big iron around anymore :-) I do have most of the
vintage parts stashed. I have 3 used Nationals...look pretty good, seller
said they were pulls on general maintenance.

Thanks,
Jim Mora


-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Wednesday, February 15, 2006 10:51 AM
To: tesla@xxxxxxxxxx
Subject: RE: Testing 833A's

Original poster: "Jonathan Peakall" <jpeakall@xxxxxxxxxxxx>

Dave,


 > Jonathan,
 > A few years back, the Antique wireless assn journal had an article on
 > testing power tubes.  I think I still have the scan of it at home.  I
 > can eMail it to you if you want.
 > Dave

That would be great! Please send it to jpeakall@xxxxxxxxxxxx

Matt,

       Step 1
 >   filament test:
 > The filament requires 10 V and should glow brightly while drawing 10
Amps.
 >
 > Step 2
 > Once the filament has stabilized, applying 1000 V to plate and no
 > grid bias, should result in a plate current of about 250 mA.
 >

Thanks, that's a good start. I had already tested the filaments, they are
good. I'll test the plate current tonight. What range of current draw
constitutes "good"? I assume that 250mA is ideal?

Thanks all!

Jonathan