[Milsurplus] BC-611 case screw and MWO questions

[WA5CAB at cs.com]

Mike,

The original top cover retaining screw is #8-32x7/16 Binding Head Captive 
Machine Screw, Black Oxide finish.  Signal Corps Stock Number 6L6832-7.94S.  No 
lock washer and no flat washer.  The seal was a fiber or neoprene flat washer 
that fits the counterbore.  I've seen some of the correct screws but with green 
finish and surmised they were from a depot respray job.  Or maybe post-war 
replacement parts.

BC-611's stayed in service with several NATO nations (Italians and Greeks at 
least) into the 60's.

MWO SIG 11-235-6 dated 4/1/45 repeated parts of earlier ones, replacing 
bakelite mic and earphone caps with aluminum ones, and installing MC-162 earphone 
cup on earphone cap and M-367 canvas cover on mic cap.

We think that -7 was installation of the ground buss wires alongside the tube 
sockets and -8 was the installation of a metal clip on the ON/OFF tab on the 
bottom of the antenna.  This is conjecture based on cases with stamped MWO's 
and what was found inside.  I've never come across the paper hard copies of the 
MWO's.

In a message dated 9/29/2005 6:15:00 PM Central Daylight Time, 
kk5f at earthlink.net writes: 
> I've looked at several BC-611 units over the past few years and seen a 
> different type of screw holding the top plate down on each.  My only such unit 
> has a natural-metal-finish binder head screw with external tooth lock washer, 
> but I've seen:
> 
> (1) Flat head screw (?!?)
> (2) Round head screw
> (3) Binder head screw with head diameter well less than the diameter of the 
> countersunk hole in the top plate
> (4) Binder head screw in OD green finish
> (5) Screws with and/or without lock washer.
> 
> Has anyone seen enough of these sets to describe the "official, 
> as-manufactured" top plate screw?  I assume that none of these top plate screws had a 
> capture device to prevent separation and loss of the screw from the top plate.
> 
> My BC-611-F shows a red painted date of APR 56 on it.  That seems awful late 
> for such a set to still be in service.
> 
> My BC-611-F has markings indicating that MWO SIG 11-235-7 was performed on 
> it.  My 1945 dated TM 11-235 only describes MWOs up to "-5."  I'd be 
> interested in knowing what MWOs later than "-5" did.
> 
> 

Robert & Susan Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
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