[Heath] SB-102 Idling plate current

[G3OOU at aol.com]

Hi Joe
 
Apart from the possibility that the final tubes have a problem does  
anything else change, for example the negative bias voltage or screen/anode  
supplies? Are the finals stable and correctly neutralised?
 
Any resistors/pots around the finals that are misbehaving or out of  
tolerance?
 
73

Bob

Bob F Burns G3OOU,  G-QRP 6907, @BobFBurns
Crystal Palace Radio & Electronics Club: _www.g3oou.co.uk_ 
(http://www.g3oou.co.uk/) 
Technical web site: _www.qsl.net/g3oou  

 
In a message dated 23/02/2016 03:36:14 GMT Standard Time,  
heath at puck.nether.net writes:

 
Hello fellow Hams, Name is  Joe, call WA3CKA, builder of my SB-102 in 1972, 
updated 3 years ago in use  everyday.


I find that the idling plate  current rises above the 50 ma setting as I 
transmit in a normal length CW QSO  maybe 5 minutes.  



Final tubes were new old stock  now 3 years old.  Any suggestions as what 
may be causing this  condition.


You can speak to me in  technical terms if you want as I am a retired 
electronics tech.  So far I  find nothing wrong.


I only do CW.  73 to  all.


Joe WA3CKA








_______________________________________________
Heath  mailing  list
Heath at puck.nether.net
https://puck.nether.net/mailman/listinfo/heath


_ (http://www.qsl.net/g3oou) 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/heath/attachments/20160223/08f01382/attachment.html>