[Milsurplus] KWT-6 Family, was AN/URT-18 transmitter??

[Jim Whartenby]

Hi Dave
Every now and then RCA got real fussy about the patents they held.  I have a 
few manuals from the RCA Patent Department archive at RCA Laboratories in 
Princeton, NJ.  Lots of typed onion skin paper detailing what circuits were in 
any radio from any manufacturer that RCA still held the patent rights to and 
when those patents would expire.  Even radios built by other RCA divisions 
were gone over by the Princeton patent department.

There was some kind of manufacturers association which looked over whatever was 
made so that royalties were paid to the patent holder.  I am quite sure that 
things went both ways and that RCA paid other patent holders either directly, or 
through patent pool swaps, the royalties owed.  All of this was for commercial 
and military radios, I don't remember seeing anything on consumer radios except 
for a loose leaf "book" I have of stickers that RCA required licensees to put on 
all the consumer radios that they manufactured and that had active RCA held 
patents.  Sadly, what I did not "acquire" went to the dumpster as RCA was broken 
up.

Do you want close up photos of the various KWT-6 modules and overviews of the 
whole radio?  How crazy do we go with this?

Have four of the family here:
URC-32A, complete and operational, on loan from W5OR
KWT-6 Type 8, complete; working on receive, keying problem on TX, also on loan 
from W5OR
310F-1 complete except for 153H2 junction box, cables and proper rack*, not 
operational, eBay find
310F-6 complete and operational, this is the only radio in the 7 foot rack, all 
of the others are cut down to 6 foot, eBay find

* I cobbled together a 6 inch wide aluminum rack out of two 3 inch wide aluminum 
racks, Blue Ribbon connectors are being cobbled together as I find the time and 
parts.  


As always, things are done a shoestring budget.  I would have finished the Type 
8 except that I am distracted by the latest find, the 310F-1.
Jim



----- Original Message ----
From: David Ross <ross at hypertools.com>
To: milsurplus at mailman.qth.net
Sent: Sat, November 13, 2010 3:27:28 PM
Subject: Re: [Milsurplus] AN/URT-18 transmitter??

Jim & John & the gang -

  I would love to see photos of your radios.  The photos in the KWT-6 
'family album' are not very good -  hard to make out details on the 
interesting automatically-tuned versions.

  I can put the pix up on my website, if you like.

  In the early '90s, my favorite scrapyard in Sacramento came up with 
some KWT-6 modules (probably from McClellan AFB).  They had the Collins 
look to them, silkscreening & type font were very familiar, but they all 
had RCA patent decals on them.  Maybe RCA took over building the old 
Collins gear when Collins went on to newer designs  (my URC-32B was 
built by LaPointe Industries under a 1969 contract).

  In the late '90s, I found some sort of KWT-6 family control at Fair 
Radio Sales -  it was an ARC-58/TRC-75 frequency selector in a 
KWT-6-style chassis.  Does this belong to one of your radios?

thanks & 73, good luck with the beasts
Dave Ross    N7EPI





On 11/13/2010 12:04 PM, Jim Whartenby wrote:
> Sure John, pictures are welcome!
> I have some manuals which I would be happy to copy if that will help.  Also 
>have
> gained some experience working on two URC-32s and one 310F-6 so I know some of
> the pitfalls.  Reworking the power supply and blower motor are first order
> issues, followed by getting the SMO back in sync.  The Interpolation 
Oscillator
> is the problem there.
>  
> You say that the frequency selector is different?  I guess that there is no
> mechanical odometer type frequency readout?  If the frequency selector is 
>rotary
> switches then this radio could be like the 310F-1 which is an auto-tuned radio. 
>
> Look for two servo amplifier modules, one 5 watt, one 2 watt, easily 
identified
> since there are two small pots on the module front.
>
> I can take a picture of the 310F-1 to give you an idea what it looks like.  
All
> is mounted on the rack except for the motor-generator.  I will have to make a
> one inch spacer for each side of the rack so that the back of the M/G assembly
> doesn't hit the plenum.
> Jim
>
>
> ----- Original Message ----
> From: John Vendely<jvendely at cfl.rr.com>
> To: milsurplus at mailman.qth.net
> Sent: Sat, November 13, 2010 11:24:22 AM
> Subject: Re: [Milsurplus] AN/URT-18 transmitter??
>
> Hi Jim,
>
> Thanks for the reply.  Yes, the AN/GRR-13 has exactly the same style of
> construction as all the KWT-6 variants--the familiar light gauge metal
> covers with toggle snaps, with the entire set mounted in an open relay
> rack.  The individual chassis are designed to unlatch and swing out for
> servicing.  The frequency selector unit looks a bit different from the
> 310F-6, as does the number and arrangement of subassemblies.  I always
> assumed it was merely a military nomenclatured version of a standard
> product, but I don't see anything in the Collins catalogs of the time
> which looks identical.  I really have never spent much time analyzing
> it, though I'm sure it must be just another variation on the KWT-6
> theme.  Manuals for the other variants might well serve as a guide. 
> This discussion has certainly piqued my interest, and I could furnish
> some pix in case you're curious about it...
>
> 73,
>
> John K9WT
______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html