[MRCA] TDO/BC-640 Items WTB:

[WA5CAB at cs.com]

Joe,

The mistake in your original post was that you wrote "BC-640" and meant 
"BC-460".  That confused several of us who know the BC-640.

I have an original manual here on BC-460-B dated 30 June 1941.  
Characteristics of the TDO that you've mentioned (physical size, weight, tube complement, 
early Collins Autotune, etc.) all match.  So I suspect that allowing for 
whatever differences existed between different models of BC-460 and different models 
of TDO, they are probably similar.  Not mentioned in your posts is the 
frequency range.  This manual (preliminary copy of TM 11-812B) says 2,000-16,000 KC. 
 However, per NAVSHIPS 900,116 dated 15 April 1946 specs and photo of TDO, 
front view photos look about the same but it says 2,000-18,1000 KC and a lot 
more tubes in the RF chain.  So the TDO, strange is it may seem to those familiar 
with Navy versus Signal Corps WW-II sets, must be a later variant.

FYI, in the BC-640B the modulation transformer (T22A) looks like the HV 
transformer (T23A) except about 80% size and with smaller diameter through bolts 
holding the core and end bells together.

In a message dated 11/29/2005 2:23:07 PM Central Standard Time, 
Yardleyite at aol.com writes: 
> In a message dated 11/29/2005 2:31:11 PM Eastern Standard Time,  
> enrpnr at erols.com writes:
> 
> I assume  that the nomenclature "TDO/BC-640" is commercial.  The military  
> BC-640 is a different beast, I know, I have  one.
> Ray
> 
> 
> 
> Ray,Everyone who responded,
>                                            Many apologies for this and I 
> appreciate the information. I've tried to  cross-reference the Collins "TDO" 
> and 
> find as much information as I can on it. I  originally thought the 
> BC-460,Collins 16F, and TDO were all the same from info  obtained on the 
> internet. 
> Apparently not and I appreciate the information from  all those who 
> responded. 
> 
> What I need the parts for is a Collins "TDO" transmitter, rated at 400W CW  
> and 250W AM Fone. It has the Collins autotune setup with dials that look 
> like  
> they're from an ART-13, and a standard telephone type dial as the 
> controller.  
> The tube lineup is a pair of WE 249C's and 866A's as the HV rectifires and 
> the  PA deck uses a pair of 813's modulated by a pair of 805's. It stands 
> about 
> 78"  tall, 30'' or so deep and wide, and weighs about 1,000 lbs.
> 
> Any lead(s) on any exciter and or speech amp decks will be greatly  
> appreciated. Ditto on a manual and a modulation transformer.
> 
> Best Regards,
>                      Joe Cro N3IBX 
> 

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)