[Milsurplus] BC-221 question for the pureists

[WA5CAB at cs.com]

John,

It's SCR-211-(*), not -221-.  First, this is a case of nomenclature error.  
"SCR" stands for "Set, Complete, Radio", and the set or system nomenclature 
should have been "IE" for "Instrument Equipment".  But in any case, SCR-211 is 
the complete set consisting of a BC-221 ("BC" means "Basic Component"), canvas 
bag or cover, shoulder strap for the bag, headset, spare tubes (usually), spare 
crystal (sometimes), bristol wrenches, batteries, and two copies of TM 
11-300.  BC-221-(*) is the heterodyne frequency meter itself.  The suffix letters of 
the SCR and the BC always match (which is an exception to the general case).

As is the general case with Signal Corp equipment, the suffix letters 
indicate some combination of new order, different contractor and/or minor or major 
difference for other models.  There are six major differences between models:

(1) Contractor
(2) Front panel layout
(3) Tube complement (6/7 pin glass, loctal or metal octal)
(4) Modulation (or not)
(5) Case material (aluminum or wood)
(6) Battery compartment layout.

Don't know of a URL but someone else may.

There were two types of AC supplies built (PP-79/UR (fits only BC-221-B and 
-Q) and RA-133-(*) (fits all other models).  To the best of my knowledge, none 
were supplied with the equipment as original issue.  Most of the BC-221 models 
predate the earliest P/S production.  I've never seen a BC-221 with paint in 
the rectifier mounting holes.  And at a guess, out of several hundred BC-221's 
that I've seen, no more than 5% had or had been modified for, the rectifier.

In a message dated 3/4/2005 12:37:05 AM Central Standard Time, jfor at quik.com 
writes: 
> Since I don't own one and am not familiar with them, what is the difference
> between an SCR-221-x and a BC-221-x, where x can be any applicable letter(s)
> like M or AH ?  I understand there are a bunch of options designated by the
> letters.
> 
> Also, is there any good table or chart on-line that lists the options and 
> suffix
> numbers? A URL would be appreciated.
> 
> Finally, is there more than one type of AC power supply and were they all 
> 'add
> ins' or were some models originally delivered as AC line powered?
> 

73
Robert Downs - Houston
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