[Milsurplus] RE TV-7 B/U tube tester- ANOMALY ?

[pete williams]

I came  across a  funny one ----  testing a  6ES8 - a  twin  triode
for  RF used as a  cascode  amp. . with the  settings in the  book
each  triode  section tested differently for  4 tubes , 3  being
allegedly new.
Not only that but one  showed  shorts. . Some sent the  meter  hard
over full scale +.Sufficient variation of  data  to  consign to the
round  file.!
 In the  radio  from  whence  it  came  ALL tubes  functioned
perfectly.
The  settings  are identical  to a   12AT7 with  fil and   bias
different and  no problems with  testing 12 AT7
 QUESTION. Is it possible that because of the high  gm of this  tube.
the test proceedures do not make allowance  for the  internal
construction which I understand ,means  very close proximity of  some
of the  elements  -- grid to plate  for  example .
It's hard to reconcile two tubes with the  same  basing but  differing
types, one - 6ES8- goes ballistic on test even tho'  they  work fine
in the radio  -   a Racal RA 117. !
 Comments please !-- maybe other tubes act up.
 Cheers
Pete
.


Pete D . Williams
METUNG 3904
Australia
jupete at bigpond.net.au