[Boatanchors] OA2 PROBLEMS SOLVED

Magoo magoo at isp.ca
Thu Aug 13 07:54:25 EDT 2009


In an earlier post I had indicated a problem with a power supply where OA2 
tubes appeared to be drawing too much current.  I received a number of 
responses which helped me solve the problem, and I once again thank all who 
provided me with guidance.

It would appear that the transmitter had had several modifications installed 
which changed the current requirements on the regulated lines.  The series 
dropping resistors to the OA2s, however, were not changed to reflect the 
change in current requirement, and so each OA2 was pulling close to 45 ma 
unloaded and some 35 ma loaded.  The series resistors have now been changed 
so that each VR tube pulls 25 ma in standby and 30 ma under load. 
Everything appears to be running cooler as well.

73, Bill VE3NH 



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