[Milsurplus] Showdown @ IRE Corral

[Unserviceable but Repairable]

Mike that's the 12/56 IRE Proceedings on Communications.

Got it out for a read along with a 1/57 CQ artl. by W2CRR, Costas.  This
written for a layman & dang good.  YRS-1 flyer was in same folder.

In those days coherent DSBsc was flogged as an interference killer.  What's
today called the Costas Loop took two detectors.  One w. BFO injection
lagged 90deg, other un-lagged.  2nd yr college math'd show if BFO
synchronized w. SBs, one det. wud peak, other wud null.  And a discriminator
wud steer BFO to that state.

Now have you heard of the GE YRS-1?  That sales flyer had a ruff
schemat dated 5-49.  Dang if it isn't about a CE Sideband Slicer w.
BFO steering!  Seven YEARS before Costas' publication.

A "phasing method" SSB demod. if you lock the BFO.  And BFO-lock
was a panel option.

YRS-1 sold as qrm-fixer since u cud pick a SB to reduce interference and
automatically supply a carrier for selective fade distortion.  1949 &
GE tiptoeing into ham arena yet.

Looks like GE thot DSBsc a good offensive against Collins & SSB in
those years of Collins giving KWS-1s to Lemay & Adm Thunderputz, ret.

Before more DSBsc, an SSB aside.  Here please note Collins hardly 1st 
w. a filter SSB generator.  '51 QST art'l using FT171 BC604 xtals in a 
~500kc exciter probably 1st Ham artl. on scheme.  And.  And WE SSB using 
50kc generation & LC-filters was in heavy HF point-to-point svc during 
WW2 (See TM 11-487 in misc. section)

No Mildred, Collins dint invent mech. filter either.

Cud Art Collins, Mr. SSB, be from same gene pool as Bill Gates? 

Collins due credit for KWM1 invention.  All SSB xcvrs copied it 'til 
DSP SB-generating things of today.

Back to GE & "DSBsc a good offensive."  Before IRE Symposium, GE submitted
AN/FRR-48 (XW-1) rx & tx-s AN/FRT-29 (XW-1) & 30 for USAF eval.

FRR-48 looks strangely like a NC-300 and, catch THIS.  It's 1956 Direct
Conversion.

But something went wrong w. eval.  They weren't adopted.  Bet most of 
Cedar Rapids had their nose in the hops after the announcement.

Where's Costas loop today?  In all V34 56k modems, that's where.  It
ensures all the "phase constellations" are in the right place and
the bits come out OK.

Another fad term is QAM, quadrature AM.  Not a Costas loop thing, but
uses "90 deg. orthogonality" principal in Costas loop to allow indepentent,
non-interfering info streams on DSBsc.  Where's that today?  Same place it's
been since 1953.  Your "color compatible" NTSC color TV.  (3.58 mhz 
coherent dsb, ie QAM)

I'll close the way Costas did in 1/57 CQ

     I would not like to oversell DSB; it won't
   perform miracles.  However when compared 
   with SSB we may draw the following con-
   clusions:

     1.  SSB has no power advantage
     2.  SSB will not reduce interference
     3.  SSB is much harder to generate

     That's the end of my story, which is a good
   thing because I can see them coming for me
   now.


   Marty