[Milsurplus] Collins Modulators For Sale

[COURYHOUSE at aol.com]

WOW!  ok  well that is  good  too... actually   better for  us  than 
something  for  GRT-3    after  45  years  all these  numbers   run  together 
unless I look them up sometimes!    We  are  trying to get the grc-27 
transmitter...
we have one of the receivers already here.    I worked on  them at  Luke  
AFB in the early 70s  before they were rivet  switched  out.
 
 
In a message dated 10/14/2013 10:10:28 A.M. Mountain Standard Time,  
jvendely at cfl.rr.com writes:

The  MD-129 is part of AN/GRC-27, which was a synthesized 220-400 Mc (100 
kc  steps) fixed station set based upon the design of the ARC-27.  It  
provided supply voltages as well as modulation power to the associated  
transmitter. Transmitter output power is 100W, so these modulators do  
not develop "a cool 500 watts", more like 50 watts.  Most amateurs  
greatly overestimate the output power of military equipment, based on  
its size in relation to the amateur equipment they're familiar with, and  
the seller is apparently similarly influenced.  Input power  consumption 
is certainly at least "a cool 500 watts", however, with the  transmitter 
at 100% modulation.

About 30 years ago I had a complete  GRC-27, and kinda wish I still did.  
I got it for essentially  nothing, and ended up giving it away.  They're 
huge, impressive, and  beautifully built.  They seem to work just fine 
down into the 220 Mc  amateur band, and I used it there upon occasion.  
The GRC-27 was a  beautiful set, so I hope it's possible to save the 
modulators, and  possibly restore a system...


73,

John K9WT

On  10/13/2013 11:43 PM, COURYHOUSE at aol.com wrote:
> I think these are   for grt 3 transmitters??
> if we can save them and get them to Arizona  in the back of a truck or   
car
> that is headed  here  anyway    we would provide  a  home  for  them
>   
>   
> the weight of  these   is  why I ended up  after a car   accident   
working
> at the mars station...    too  heavy for a crip  to lift!
>    
>   
> Ed Sharpe Archivist  for SMECC   _www.smecc.org_ (http://www.smecc.org)
>    
>   
>   
> In a message dated  10/13/2013 8:26:37 P.M. US Mountain Standard Time,
>  iron.horses at verizon.net writes:
>
> Dear  Military Surplus  Newsletter
>
>
> Could you please include the  following  text in your next issue.
>
> I have these  wonderful boat anchors and would  like to find a good home
> for  them and some remuneration as well if  possible.
>
> I place  the text below.
>
>
>
>
> I HAVE FOR SALE   TWO SURPLUS COLLINS-MADE MD-129s MODULATORS/POWER 
SUPPLIES.
>
>  THEY  HANDLED LARGE VHF TRANSMITTERS IN THE EARLY 50'S. I BELIEVE  THEY
> PUT OUT A  COOL 500 WATTS OF AUDIO.
>
> I BOUGHT  THEM THIRTY YEARS AGO FROM A SURPLUS  DEALER IN ARIZONA (DAVIS
>  MONTHAN AFB) WHO WAS MELTING DOWN PLANES FOR   ALUMINUM.
>
>
> THEY HAVE BEEN CAREFULLY STORED EVER  SINCE.
>
> THESE  UNITS HAVE LARGE XFORMERS, CHOKES AND  CAPACITORS AS WELL AS LARGE
> AUDIO  SECTIONS. THEY HAVE SWITCHED  MONITORING METERS AND COOLING FANS
> THAT  HUSTLE AS  BLOWERS.
>
> BOTH UNITS ARE BY COLLINS, BOTH HAVE LARGE  POWER  SUPPLIES WITH POWER
> SUPPLY AND MODULATOR INTEGRATED IN THE  SAME LARGE RACK  ASSEMBLY.
>
> THEY ARE COMPLETE EXCEPT THEY  DO NOT HAVE ANY OF THE  TUBES.
>
> THE AUDIO FINAL TUBE WAS A  LARGE TWIN, LIKE AN 832, BUT  HUSKIER.
>
>
> THE  RECTIFIERS AS I REMEMBER WERE 2B28's.
>
>
> THE  CASE  IS ALUMINIUM, CONFIGURED FOR NORMAL RACK MOUNTING.
>
>
>  THERE IS A  FULL SCHEMATIC PRINTED ON THE UNDERSIDE OF THE TOP  PANEL
> USING AN  ENGRAVING PROCESS WHICH I AM AT A LOSS TO  DESCRIBE.
>
>
> THEY WEIGH  ABOUT 150  #'s
>
> WOULD LIKE THEM TO GO TO A GOOD HOME AND WOULD LIKE  A  REASONABLE OFFER.
>
> TOO HEAVY TO SHIP, BEST TO PICK UP  IN  PHILADELPHIA.
>
> W3AGR
>
> Thanks   W3AGR
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