[Motorola] P23AAM Help needed

[Geoff Fors]

I checked and the schematic I have for the NU137 is dated 12-56, which I 
suspect is the same as your copy.

That being said, the Motorola FM Schematic Digest by S. Wolf, the red 
edition, at Page 79 does show a set of NU-137 schematics dated 1958.  I have 
not compared them with the '56 schematics to see what if anything is 
different.  Do you have that book?

The transistor crosses to an NTE 104, which is a Ge PNP TO-3 cased type with 
an Hfe of 90.  The originals were probably far less than that.  I would 
think that almost any Ge PNP TO-3 transistor, like that in an old car radio 
audio stage, would work.

There may have been some service bulletins on these over the years which 
resulted in modifications.

There was also a Z23AAC, which had a fully transistorized receiver, which 
would later become the H23BAC.  Apparently it was never made with the NiCad 
supply, unlike the H23BAC.

Geoff
WB6NVH
Monterey CA