[ARC5] SCR-522 vs TR-1143

[Mike Hanz]

On 7/8/2012 12:27 PM, Jack Antonio wrote:
> Electrically, the TR-1143 covered 100 to 125, vs 100 to 156 for the
> -522.  The receiver IF is 9.72Mc vs 12Mc.  I find it interesting and
> probably not a coincidence that the AN/ARC-1 also used a 9.72Mc IF.
> The receiver crystal multiplier is 18 for the whole range.
>
> As an aside, wasn't there a companion unit that covered 125 to 156?
> What was its designation?

It wasn't identified in the green books, Jack.  That's why I mumbled 
over it in the writeup on my website.  On page 80 of "Signal Corps: The 
Test", the narrative only records the following (my comments in 
brackets), "The British had originally contemplated two sets to cover 
this great range of frequencies [100 to 156 megacycles], all of which 
the multiple needs of aircraft communication required.  But the 
Americans had believed it possible to cram the entire band range into 
one set.  Rives [Col. Tom C. Rives, Chief of the Radar and Aircraft 
Communications Branch in the Office of the Chief Signal Officer] had 
argued for this and won his point.  American laboratories [not specified 
but probably included Bendix, working with the Aircraft Radio Laboratory 
at Wright Field] succeeded in a feat of collapsing two sets into one, 
occupying no more space and weight than the original British TR-1143 had 
taken up and with only half the ultimate frequency coverage."

In a cryptic handwritten note on the page in my copy is a notation that 
the British designation for the SCR-522 was TR-5043.  I have no idea 
whether this meant the 125-156 unit or the entire SCR-522.

73,
Mike