[Milsurplus] Spurious PRC-74B synthesizer claim on eBay

[Mark]

Item 200582646445 has this claim:

"For sale a PRC-74B synthesizer in NOS condition.This is new never used condition. Basically with this synthesizer you can turn your PRC-74A into a 2-18Mhz radio changing it to a PRC-74B. A rare item and in this NOS condition."

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This is utter, complete garbage!  There is nothing "basically" about this.

1) The P.A. in the PRC-74 and PRC-74A will not operate much above its upper limit of 12 mc.

2) The components in the R.F. modules have very different specs for the different ranges 2-12 and 2-18mc.  The RF module is a very critically-tuned series of TRF stages and the 74/74A versions will NOT work in the 74B.

3) The megacycle numbered disk in the 74 has (obviously) only 2 through 
11 on it.

4) I believe there may be differences in the mechanical cam band switching mechanism behind the panel.  Don't know for sure because I've never tried interchanging them because the conversion makes no sense for the reasons above.    

--Mark Francis
  KI0PF

Author of "Mil Spec Radio Gear Volume 2"
available direct from the author,
$29 cash/check/MO including postage, 
$30.17 via Paypal, both within U.S. 
(foreign buyers please contact me).
Signed by request.

Excerpt here:
http://www.mmfrancis.com/MSRG2/MSRG2.pdf

Also available from:
Universal Radio
http://www.universal-radio.com/catalog/books/3495.html
Fair Radio Sales
https://www.fairradio.com/catalog.php?mode=viewitem&item=6569
Electric Radio
http://www.ermag.com/index.cfm?v_link=product_detail&v_key=415

****

Volume 1 is still available direct from
CQ Magazine,
http://store.cq-amateur-radio.com/Detail.bok?no=113
Universal Radio,
http://www.universal-radio.com/catalog/books/0415.html
and 
Amazon.com