[Drake] Drake T-4XB - Found a modification

[Bob Scott]

I am working on my Drake T-4XB.  My immediate problem is that I am not  
getting any bias indication on the front panel meter, nor any output.   
This is my first time working on this and I noticed that a previous  
owner put a switch on the back panel that interrupts the 12.6 VAC to  
the finals.  Why would one do that?

I will let you know what I find with the transmitter, but the purpose  
of the switch eludes me.  I hope there are no additional modifications  
to be discovered.

Thanks.

73, Bob Scott W4ZY
Woodbridge, VA