[R-390] Modification?

[mikea]

On Thu, Oct 19, 2006 at 01:32:49AM -0500, Tom Norris wrote:
>
> On Oct 18, 2006, at 11:14 PM, ToddRoberts2001 at aol.com wrote:
>
> >
> > It looks like an R-1247/URR variant of the R-390A. These had
> > external inputs for the 1st, 2nd and 3rd Local Oscillators on
> > the rear panel that were provided by an external synthesizer for
> > high-stability operation and were supposedly used by NASA in the
> > Apollo space program. The radio can be tuned like a normal R-390A
> > without the external synthesizer. Several small relays inside
> > switch it over for use with an external synthesizer when needed.
> > 73 Todd WD4NGG
>
> Yea, it's got the rear panel for it, and from the pictures there are
> some of the cables inside. I wonder if all the "guts" for the rest
> of it are there? Only the radio is collectable. Used to be folks
> like Rick Mish would remove and toss the adaptors and other things
> that were inside.... myself, I have the synthesyser decks, but I'm
> not sure I'd ever use it either since you still have to tune the
> radio to frequency THEN tune the very noisy 60's vintage frequency
> synth decks.

Don't they also use some R-390 modules because the corresponding R-390A
modules aren't phase-flat and so would have made the radio less usable 
for D/F-ing? 

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin