[Milsurplus] BC-611 MWOs

[WA5CAB at cs.com]

One of the major problems (from both a collector and a current 
maintenance/repair standpoint) with the BC-611 is that it only takes one thumb nut and one 
screw to remove a chassis from a case and put it into another case with a 
different model nameplate. All model chassis will fit all model cases. And only the 
A, B, D, some C and some F have the model letter indicated on the case. And 
it is printed on a part subject to replacement. And the replacement parts 
(bottom contact plate) don't have model letters.

So the MWO's stenciled on any cases that you see may or may not actually 
apply to the chassis inside. Except for the ones that didn't apply to the chassis 
but to some other component(s).

Anyway, here's the list as I have it. Part of it is from hard copies of the 
MWO's. Part from references in other publications (mostly T.O.'s) and part is 
inferred from noting what was stenciled on cases when certain changes were seen 
on the chassis inside (but see paragraph one).

MWO SIG 11-235-1 08/08/44 Replacement of cast PTT actuator with stamped 
switch kit.

MWO SIG 11-235-2 08/25/44 Added plastic antenna support at top of chassis.

MWO SIG 11-235-3 10/18/44 Replacement of bakelite mic and earphone caps with 
aluminum ones.

MWO SIG 11-235-4 01/01/45 Reinforced block at top of chassis for screw 
retaining chassis in case.

MWO SIG 11-235-5 01/25/45 Homing Modifiction Kit MC-619.

MWO SIG 11-235-6 04/01/45 Repeated -3 and added MC-162 to earphone and M-367 
to microphone caps. For hot weather breakage and cold weather personnel 
protection.

MWO SIG 11-235-7 ??/??/?? Added copper wire ground buss between all socket 
ground plates.

MWO SIG 11-235-8 ??/??/?? Metal clip added to bakelite ON/OFF actuator on 
antenna bottom section.

As a comment, although several changes or additions were made to electrical 
circuit components or values during the production lifetime of the 6-1/2 
models, there is no evidence I have ever seen that any of these changes were applied 
to earlier chassis. At least not officially.

In a message dated 11/12/2005 5:47:53 PM Central Standard Time, 
arc5 at ix.netcom.com writes: 
> Anyone know what those "MWO"s commonly marked on the
> side of BC-611s are all about?
 
73
Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at houston.rr.com> (Backup email)