[AMRadio] BTA Mods

[Rick Brashear]

Well...  I have investigated the printed circuit board on the 1R2 on 
which the crystal ovens are mounted and find there have been several 
modifications and/or repairs made through out this old girls life.  My 
intention, as advised by much more knowledgeable people on these 
transmitters, is to put it back to it's original state, be sure it's 
operating at the original specifications, then begin the conversion to 
75 meters.  My concern is that some of these mods may have been handed 
down by RCA and should possibly be left in tact.  Does anyone know of 
any modifications that RCA issued concerning this portion of the 
transmitter?  I have found traces cut and spliced to other traces, a 
small variable capacitor replacing a compression trimmer and two of the 
three crystal sockets more or less taken out of use with that fact 
marked in pencil on the board.  My inclination is these are repairs made 
due to failure of components, but with no documentation on the repairs 
it's very difficult to be sure.  The board is badly scorched beneath the 
4000 ohm 10 watt resistor, but I have read this is a common issue.  
There is no trace damage to the board from the heat.

Any advice will be very much appreciated.  For those who subscribe to 
more than one list, I apologize if you receive this post more than once, 
but I want to reach the largest audience possible for assistance and advice.

Thanks,
Rick/K5IZ