[Hallicrafters] SX 42 question

[w5jo at brightok.net]

Hi all,

My SX-42 has a bit of a puzzle that I have been unable to unravel, maybe 
someone here can help.  The build date on the chassis has been obliterated 
and the serial number plate is missing.  However, the original paperwork, 
including the service bulletins, accompanied the set and is dated Jan 1949. 
The radio has the components and wiring that matches the diagram, save for 
one I have found.

There is a 4.7 K resistor across the primary of T7 which is the plate coil 
in the first RF stage for band 5 (28-55 megacycles).  My diagram does not 
show that resistor and looking at other diagrams that I can find shows a 1 K 
resistor across the primary.

Can anyone point to a service bulletin that outlines the change from the 
early version with the 1 K resistor and change to a 4.7 K.  As I said, my 
diagram does not show a resistor in that location at all.

Jim
W5JO