HP-23C schematic??

[Bob Burns]

In a message dated 30/04/2009 13:51:53 GMT Standard Time, ac1y at NC.RR.COM  
writes:


Basically, someone detached the Fil Common wire and left it  floating (taped
off) inside the chassis. I'd rather presume that this  should be grounded,
right??




Hi Sandy
 

Wrong! None of the filament connections are grounded in the power supply,  
only in the destination transceiver, in order to avoid hum loops in the  
interconnecting cables.
 

On the assumption that all of the HP23x units have basically the same  
connections, the HP23A has the filament centre tap connected to pin 8 of the 11  
way socket and labelled 6v FIL. As far as I can see, if a function is 
missing  then that pin is left disconnected.
 
I too have an incomplete HP23C manual, missing its circuit diagram.
 
73

Bob 

G3OOU
G-QRP  6907
_www.g3oou.co.uk_ (http://www.g3oou.co.uk/) 

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