| Hi Guys,
I have a Centurion that experienced some kind of arcing event which resulted in 
one of the traces on the Filter/Rectifier board that connects to the secondary 
of the transformer to actually vaporize.   I bridged the trace, replaced the 
capacitors and checked the diodes.  After repairing / rebuilding the board, I 
reinstalled it and now have normal B plus.  HOWEVER, I have 200 mA of standby 
plate current.  This suggests the bias transistor is blown and I have had this 
problem in the past.  Unfortunately, I replaced the bias transistor and still 
have 200 mA of standby plate current.  My question is:  Do any of you have an 
any idea of what to check besides the bias transistor.  Or, is there some 
common cause for the transistor to fail?  I bought 5 of them from Mouser and 
hesitate to keep replacing them until I know what is causing the failure.  The 
transistors I bought are IDENTICAL to the transistor I bought from Ten Tec the 
last time it failed.  
thanks
73
Mike WB0SND
Michael Marx
sndtubes@vacuumtubes.com
636-939-9190
SND Tube Sales
105 N. Division St.
Bonne Terre, MO  63628
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
 |