[Milsurplus] GRC109/R-1004A arrived!

Tue Sep 13 22:29:18 EDT 2011

Yes, It is used to crystal control the receiver by plugging in a crystal that has the target frequency and 455 khz added to the oscillation frequency in order to monitor a particular target frequency. Plus or minus 5 khz or so.  I forget if the 455 is added or subtracted.  It's in the TM. A sharp cookie could  get the formula and make up special crystal pairs for the 109 users.  It makes use of the rig much easier.  Hunting for the right freq would be a thing of the past.My 109 work had lots of separate tx and rx freq's so you really had to work at finding the correct signal to copy.  Not that easy with a broad banded RX73'sGregWA7LYOKinston NC
 From: bcarling at cfl.rr.com
To: milsurplus at mailman.qth.net; usbssb at hotmail.com
Date: Tue, 13 Sep 2011 18:49:54 -0400
Subject: RE: GRC109/R-1004A arrived!
CC: kk5f at earthlink.net; jrm1967 at hotmail.com; sjim747 at gmail.com

Great information on the GRC109, Greg.  Does anyone know what the "CRYSTAL" socket
 (with a screwed-on metal cover) on the front of the "reciever" is for?

On 13 Sep 2011 at 18:32, greg mijal wrote:

>  Hello there: I was a participant in the South East Asia disaster
> and can fill you in on some of the questions you raised in the Email
> about the 109 set.If anyone wants to see a very good display of one,
> go the the Airborne and Special Operations located just outside Ft.
> Bragg, in the city of Fayetteville.It's  a well light display and
> staffed by a rubber Seargeant First Class  forever teaching a class.
> My connection to the 109 is that I was trained at the JFK Center for
> Military Assistance and graduated as MOS 05B4S.  A field radio
> supervisior and the right MOS for the original 12 man A teams that
> SF was organized as back then.  I was later assigned to the 6th then
> the 5th SFG recently returned from overseas and settle back into
> it's original digs on Smoke Bomb Hill. When we jumped with the
> radios, it took three guys to carry the load.  The chief RO would
> jump with the transmitter, crystals and  the Diana  hand cipher
> system one time pad. the rest would carry whatever power supply was
> specified for the mission and the receiver.My class trained hard on
> the 109 and the GRC - 9.  The GRC - 9 was no longer part of the Army
> inventory but was handed out to foreign units as a cheap way to
> adjust artillery  fire or any traffic not more than 75 miles away. I
> found that the best antenna for the GRC 9 was a random longwire with
> a counterpoise following beneath the antenna and full lenght. The
> tuner just loves that one, easy and fast to load up.After school, I
> never saw the 109again.  They just weren't used but were part of the
> SF inventory up to around 1972.  In Viet Nam the actual radios we
> used was the FRC-93 and a new synthesized radio with MHZ, 100's of
> KHZ, 10's and 1's.  about 10 w output.  very slick and light weight
> too.So why is the 109 so heavy? It makes the radio nearly
> indistructable. Same concept that the BC 342 receiver has. The 109
> receiver is sensitive but on the broad side. Sounds nearly identical
> to the GRC-9 receiver.  There is a rubber gasket that allows the box
> to float for extended periods.  Also there is a little space to keep
> water absorbing rocks in a small tube. In rainy season areas it is a
> radio saver. The radios is very reliable if maintained. Even a
> minium amount will be just fine.  It's more or less in the same
> league as the AK 47 auto rifle.  Simple, heavy and highly reliable. 
> If anyone want more information or can pass along contact
> information for members of an organization called FANK please shoot
> me and email.Enjoy your piece of military history in good health and
> perfect peace.73's GregWA7LYOKinston, NC
>  > From: wh7hg.hi at gmail.com
> > To: milsurplus at mailman.qth.net
> > Date: Tue, 13 Sep 2011 10:10:36 -1000
> > Subject: Re: [Milsurplus] GRC109/R-1004A arrived!
> > 
> > -----Original Message-----
> > From: milsurplus-bounces at mailman.qth.net
> > [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Mike
> Morrow
> > > I've never really warmed up to the AN/GRC-109.  I bought a
> complete
> > > set at Dayton 15 years ago when they were still cheap, but I
> find
> > > that the old AN/GRC-9 is much more attractive.
> > 
> > I've never really quite understood why they had to be so heavy. 
> It makes
> > them harder to destroy if capture is a sure thing and far harder
> to lug
> > around.  I agree about the RT-77/GRC-9.  It's a far better looking
> and
> > reasonable radio.  
> > 
> > It might be fun someday to get a damaged set - no cases, maybe no
> tubes,
> > cracked panels etc - to rebuild the way I would have produced it
> in the
> > first place.  
> > 
> > > The nomenclature plate for the R-1004A/GRC-109
> > > incorrectly spells "RECEIVER" as "RECIEVER".  American public
> > > education rears its ugly head!
> > 
> > "I before E except ... hmmm ... what's that rule again?  Oh, well.
> Probably
> > doesn't apply here."
> > 
> > Best regards,
> >  
> > Michael, WH7HG ex-K3MXO, ex-KN3MXO, WPE3ARS, BL01xh ex-Mensa A&P
> PP BGI 
> > I am me.  I’m the only one who’s qualified.
> > http://www.nationalmssociety.org/chapters/NTH/index.aspx
> > http://wh7hg.blogspot.com/
> > http://kludges-other-blog.blogspot.com
> > Hiki Nô! 
> > 
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