[Amps] Alpha 76A 3 Holer; 10 meter add

[Patrick Barthelow]

Gentlemen:

On the Alpha 76A, Gray metal front Plate, 3 holer, 8874 == 3CX400  Eimac Tubes,   
Two questions, how does one add a ten meter switch function, (I am told it may only require a mechanical stop to be removed in the 
Band switch)    and,  if one of the thee no longer made   8874 goes, can it be run with two of the three remaining?  
And if so, do any PI network changes have to be made?  

Also, opening one up I am attempting to identify the transformer used, as there were sometimes used
Dahl tranformers, that were lighter than the standard.  This transformer is huge, open frame design,
with stacked square laminations, 7.5" wide across the top, and about 3.25 thick.  Dont think it is the Dahl Option.
Printed on the top laminations is probably a Mfg ID:  BTC 11163
Best Regards,   
Pat Barthelow    AA6EG