[MRCA] MRC-55/GRC-14 Radio Set-Up: Anyone have any history on this unit ?

[WA5CAB at cs.com]

Much of the weight difference between AN/GRC-19 and AN.GRC-14 can be 
accounted for by the fact that the former operated only off of 28 VDC whereas the 
latter operates off of that plus 115 VAC.  Secondary reason is that the 
T-631/GRC-14 has a rated output power of 400 watts AM compared to only 100 watts 
for the T-195/GRC-19.  Tertiary reason is that AN/GRC-14 does FSK whereas 
AN/GRC-19 doesn't.  For that, you have to have AN/VRC-29 or AN/GRC-46.  When 
you really get down to the basic specs, the comparable Signal Corps sets of 
the period are SCR-399-B or AN/GRC-26(*), not AN/GRC-46.  A few of you may 
have had the pleasure of helping move a BC-610 or a T-368.  :-)  AN/MRC-55 
(the mobile version of AN/GRC-14) included an M38A1 whereas SCR-399 and 
AN/GRC-26 included one of several different types of 2-1/2 ton trucks and a 1 ton 
trailer.

Based upon nomenclature and (which was normally assigned in chronological 
order when development was approved) and manual dates (which were written 
around the production prototype stage), original authorization of AN/GRC-14 
occurred earlier than AN/GRC-19, say 1952 versus 1953.  But serious development 
work on the AN/GRC-19 must have started immediately whereas development 
work on AN/GRC-14 probably didn't start until 1956.  Remember that component 
nomenclature isn't usually assigned until about the production prototype 
stage.

So although I have little doubt that some of the impetus behind AN/GRC-14 
and AN/MRC-55 came from Not-Invented-Here, it would appear to have been aimed 
at the GRC-26, not the GRC-19.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480

In a message dated 06/23/2017 19:19:34 PM Central Daylight Time, 
scottjohnson1 at cox.net writes: 
> I think they are about a half generation newer than the GRC-19, which was 
> in development in the 1951 timeframe.  Given that it has transistors (a 
> few), It seems to be a rather poor response to the GRC-19.  It will make a 
> few more watts, and has dual receivers, but it weighs more than two complete 
> GRC-19s.  It is clear the GRC-19 was a winner, given its length of service, 
> and the fact that it eventually got solid state power supplies, servos, 
> and blower inverters to extend its useful life.
> 
>  
> 
> Scott V. Johnson W7SVJ
> 
> 5111 E. Sharon Dr.
> 
> Scottsdale, AZ 85254-3636
> 
> H (602) 953-5779
> 
> C (480) 550-2358
> 
> scottjohnson1 at cox.net
> 
> scott.johnson at ieee.org
> 
> 
>  
> 
> From: mrca-bounces at mailman.qth.net [mailto:mrca-bounces at mailman.qth.net] 
> On Behalf Of DSP3
> Sent: Friday, June 23, 2017 4:14 PM
> To: mrca at mailman.qth.net
> Subject: Re: [MRCA] MRC-55/GRC-14 Radio Set-Up: Anyone have any history on 
> this unit ?
> 
> 
> 
>  
> 
>  I don't have an official history but the GRC-14 was the Marine Corps 
> answer to the Signal Corps GRC-19, both RATT rigs.  The receiver with the 
> GRC-14 had the RTTY converter built in and supplied the loop current to the 
> terminal unit.  What looks like an S-meter is the tuning indicator for RTTY 
> signals.  The receiver is "fair" and pretty broad.  The whole mess is much 
> heavier than the GRC-19, I think and a bit more complicated.  I've had some of 
> the equipment, to include a couple of receivers.  They are all gone, now.  
> They are post Korea and appear to be about the same vintage as the GRC-19. 
>  I never did see any real quantity of GRC-14 gear on the market or for 
> sale by DMRO or GSA, etc., just a few receivers.
> 
> Jeep - K3HVG
> 
>  
> 
> On 6/23/2017 1:20 PM, Doug Hensley wrote:
> 
> 
> 
> >>  Anyone have any history on the MRC-55/GRC-14 heavy duty but mobile 
>> RATT setup?  I have seen one standard military catalog picture showing the 
>> whole thing rigged &fitted onto a Jeep vehicle.  Also have heard they were 
>> installed in shelters.  But I know very little about quantity made, when 
>> made, whether they are Korean Era only or were also used in Vite-Nahm ?  If 
>> you know alot about these or have any stories, I for one would enjoy 
>> reading about them.
>> 
>> 
>> Thank you,
>> 
>>  
>> 
>> Doug W5JV
>> 
>> 
>> 
>> 
>> 
> 
> 
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