?? - Blue glow in 2E26 final, hot 7868 modulator

Joel Govostes jwg6 at CORNELL.EDU
Fri Oct 3 23:23:47 EDT 1997


Hi all.  I'm trying to bring a Lafayette HE45B (6m AM) back to life, and
have noticed the final amp tube glows blue upon transmitting.  Wonder if
this is usual, or indicates a dud tube (2E26).  I have tried two different
tubes; both do the same.

In the same rig, the 7868 modulator tube seems to kick off a lot of heat.
It is not touchable for quite a long time after powering-off the rig, even
if it has not been transmitting.  Could this be a symptom of a problem as
well?  (Not sure how such tubes "normally" behave.)  Incidentally, I am
barely getting any modulation on the carrier, and what is there is very
distorted, though the tubes check out OK:

(6EA8 speech amp --> 6CN7--->7868 modulator-->RFC--->plate of 2E26 final).

Rcvr works fine, and carrier output appears adequate.

Thanks for comments & any troubleshooting advice...!

73,   N1AEP

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