[R-390] Frequency Synthesis on the R-390/A

[wf2u at ws19ops.com]

I have a dual-tagged Collins/Manson Labs R-390A (R-1247 on the Manson  
tag) with the requisite relay boxes/connectors on the rear panel.

I had the Manson synthesizers which are now in Tom's (NU4G)  
possession. Tom wanted to swap a regular R-390A for mine, which I was  
amenable to since he bought the synthesizers from me and I didn't need  
the R-1247 features.
For some reason Tom never got to arrange the swap (I think he didn't  
want to ship or didn't have time to drive and meet me somewhere - I  
don't remember), so I still have the R-390A/R-1247...

73, Meir WF2U
Landrum, SC



Quoting Steve Toth <stoth47 at yahoo.com>:

>
>
>
> Tisha
> I would also be interested in a copy of the docs you found and pay   
> for the copying and postage.
>  
> I have what is possibly an R-1981.  It's an early Collins with the   
> front panel that takes a long Collins tag instead of the Manson Labs  
>  tag, and it has the 17Mhz input / output mods installed.  The   
> previous owner picked it up at an estate sale in Florida of a ham   
> that worked for NASA and claimed it was formerly used in Vietnam.    
> It's either a NASA R-1247 with a changed out front panel (most   
> likely - although it has no Manson labs markings on any of the   
> modules), or an R-1981 - I'm just not sure which.
>  
> Per the R-390A FAQ page - The R-1981.
> "The R-1981 was a R-390A modified to bring out the 17 MHz, HFO and   
> VFO signals to the rear panel and to insert an error correction   
> signal for high-stability operation. It was a part of the TSC-25   
> communications system. The modifications were done using a kit of   
> parts from The Technical Material Corporation (TMC) under contract   
> number 14385-PC-58."
>  
> And from a past email I received off list a while ago from Tom, NU4G  
>  (thanks Tom!):
>  
> "I also have the two synthesizer decks for your R-1247 - I was   
> supposed to also get an R-1247, but it never materialized.**
>
> **(Which is just as well.  Imagine dialing up a freq on the   
> receiver, then cranking on TWO boxes - one for MC and one for KC, to  
>  tune to a freq.  The GRC-129 system was an interesting contraption   
> that used two of your receivers controlled by the synth - the pair   
> was set up in diversity mode. The transmitter was a highly   
> Manson-modified T-368 that was redesigned for SSB only.    
> "Contraption" is a good system description, as is "haywire."  There   
> were better things in production at the time, who knows how the   
> contract for that system was ever approved. heehee Nonetheless, it's  
>  still interesting.)
>
>  
> -- Steve
>
>
>
>
>
>
> Woodinville, WA
> In any hobby there is no such thing as "over kill" - just budget limitations.
>
>
> --- On Fri, 8/14/09, Richard Green <k7yoo at yahoo.com> wrote:
>
>
> From: Richard Green <k7yoo at yahoo.com>
> Subject: Re: [R-390] R-390 Digest, Vol 64, Issue 21
> To: r-390 at mailman.qth.net
> Date: Friday, August 14, 2009, 10:28 AM
>
>
> I thought that version of the R390A was called the R 1247. I have   
> one that was done by Manson Labs and it has the most linear PTO of   
> ANY Collins radio I have ever owned. I would like a copy of the docs  
>  on this version and certainly would pay for copying and postage.
>
>
>
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