[AMPS] L-4B

[Jim Henderson]

Esteemed Reflectees:

        Don't see much commentary on the L-4B, but mine just cratered. Was
in standby when a crack and long fizzle sound came out of the RF section.
The grid resistor opened up, and the meter needle pinned to the left
(minimum) direction. 

        I happened to be looking right at the RF section when this happened,
and saw no arc or tube glow. Anybody know if this is a common failure mode?
Since the tubes were biased off at the time, parasitics don't seem likely,
and I ohmed the tubes and see no shorts.

        I had a diode stack go out on this unit once, but never had a RF
section pronlem in the 12 years I've had this amp.

73 de Jim, KF7E


        
Jim Henderson

jhenders@zianet.com
jhenders@tdrss.wsc.nasa.gov
kf7e@k5di.nm.usa.noam


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm