[Amps] Checking 12by7

[K6KWQ at aol.com]

In a message dated 4/11/2003 8:19:42 AM Pacific Daylight Time, 4z4tl at iarc.org 
writes:

> Is there a way to determine if a 12by7 is operative , out-of-circuit
> (resistance checks) ?
> 

In my many years of vacuum tube service, the only true test is substitution 
with a known good tube
K6KWQ
12 volt radios are for sissies
real radios can kill you.
QRO? Still can't make it? You need "more power"