[Milsurplus] BC-348 question on stamps

[David Stinson]

----- Original Message ----- 
From: "John Hutchins" <olegerityincj at austin.rr.com>
Subject: [Milsurplus] BC-348 question on stamps


> Anyone -
> 
> I have seen on some of these units a hand painted M1 and a stamp SC3830A
>....
> What do they mean?

"M1" is a mark used to denote that an official field modification 
has been done to the unit.  In this case, "M1," as seen on many 
USAAC radios from WWII, indicates that a 1-megaohm resistor has
been connected from the antenna connection to ground in order to 
drain away the static charges that build up on aircraft antennas.
Years of research and tons of money were expended on this problem,
and the solution was a lowly resistor.  Please note that "M1" on 
a USAAC BC-348 or BC-442 is not necessarily that same as
"M1" on a BC-611; it's a matter of the technical changes
issued for that piece of gear.

The "SC3830A" in a Signal Corps Inspector's personal stamp,
indicating that the unit has been inspected by him according to his 
procedure (connections properly soldered, correct tubes installed, etc.)
and passed. 

73 Dave S.