[Premium-Rx] PR-2250 question

[Michael O'Beirne]

John

If memory serves me accurately (but not at all sure) I think Plessey 
borrowed the synthesiser design from a Marconi design called Gemini 
(possibly there were two loops).  I never experienced the lock out problem.

BTW the usual 2250 has a black panel.  A special version with a pale grey 
panel was made for the DWS for the FCO's Piccolo links.  They also used the 
BCD output (rear chassis) to drive a Redifon RFS12 automatic preselector for 
enhanced performance.  My understanding is thet the RFS 12 is essentially 
the RF stage (with four tuned circuits) of the Redifon R500.  The band 
switching and variable capacitors are adjusted by geared down stepper motors 
controlled via the synthesiser, which is controlled from the BCD switches.

73s
Michael
G8MOB

BTW

I have just seen the earlier mails re Q.  I did not realise that the RA17s 
had already been mentioned.  The sharp eyed Bond fans will know that several 
appear in scenes in the old "Dr No" and "Goldfinger".  In fact I have seen a 
mass of them at RAF Gibraltar in the control tower and more in a comcen deep 
in the Rock.  At the age of 18, it was a sight for sore eyes I can tell you.

----- Original Message ----- 
From: "John Nelson" <john at crew-green.com>
To: <premium-rx at mailman.qth.net>
Sent: Friday, May 02, 2008 8:41 AM
Subject: [Premium-Rx] PR-2250 question


> Many thanks to all who replied to my question about a newly acquired
> PR-2250. The general opinion seems to be that it's well worth keeping, so 
> I
> think I shall.
>
> It has one obvious problem, which is that when warm the synthesiser 
> refuses
> to tune to frequencies in the range x.800 to x.820 approximately and the
> in-lock LED extinguishes. I haven't yet had the opportunity to delve into
> the manuals and get my head around the synthesiser architecture. Can 
> anyone
> familiar with these receivers suggest the best place to start looking 
> within
> Module 9? It looks as though I'm going to have to find some extender 
> boards
> from somewhere . . .
>
> 73 John
> GW4FRX
>
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