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Old 29th Jan 2010, 12:23 am   #2
Leon Crampin
Octode
 
Join Date: Nov 2005
Location: Surrey, UK.
Posts: 1,869
Default Re: Magic eye valve types

EM71 (Loctal)
AC/ME (B7)
ME41/91 (MO)
1629 (IO)
Various side contact versions of the octal types and AC/DC derivatives.

Why build a rig?

An AVO 2 panel tester will test the whole lot. Configure the tester to test the triode as normal (you can then measure its gm and check its h-k resistance), then connect the screen grid supply of the tester to the target so the eye lights up. You can vary the "screen" voltage to check the brightness and the sensitivity of the eye at various target voltages.

Finally, operating the "C Ins" switch on the tester will open the eye.

Leon.
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