Hi,
I just repaired an SX-100 for a guy near Akron, He bought it new
in 1962 and made me a copy of his manual. The manual says SX-100
Mark 1A on it despite the large stamping on the Notch Filter enclosure
that said 1B.
This one failed due to a 100k 1/2 w "R" under the subchassis. PITA!
I have HI-res Pix and the schematic. PM if you still need it.
GL
/Dan
Yes bama is nice ,but the radio is a 1B,not 1A or 2.there are differences mostly around the BFO and AVC .It would be nice to have the original.There are only a few results for a 1B search and they don't give much info.