[Premium-Rx] Plessey 2280 series

[Paul Reeves]

I've just caught up with this thread so bear with me and I will check up
(monday) on the two PRS '2280' receivers I have at work. There should be
a manual as well.......
For what it may be worth I rather prefer the older 2250 receiver and
these are STILL in service with the Royal Navy (shan't say where....!)

73s
Paul
G8GJA


On Fri, 2008-02-08 at 00:23 +0000, Michael O'Beirne wrote:
> Good evening gents,
> 
> A propos John Green's comments, I believe that a special version of the 2282 
> was made for the RAF (and possibly the China News Agency) with a digital 
> display for the BFO.  I have no written evidence and this is from long term 
> memory, but I will contact an ex-Plessey friend who sold me my 2282 and will 
> report back.
> 
> I know that Plessey made a sales pitch at GCHQ because I hold some of the 
> draft documentation, but I don't know if GCHQ bought any.  It is interesting 
> because it reveals that GCHQ insisted on a 100kHz IF output even though the 
> second IF is 1.4kHz, and furthermore that the sideband sense at the antenna 
> input had to be reproduced at the 100kHz output.  One can but guess what 
> manner of computerised filtering was hung onto the IF output - perhaps a 
> form of very early DSP as well as the usual spectrum display add-ons.
> 
> Unfortunately the 2280 series does not seem to have sold well and then of 
> course Plessey vaporised after the take over by Siemens and GEC, and 
> technical support for these extremely fine radios disappeared.  The major 
> problem as far as I am concerned is the "wobbly" synthesiser tuning, the 
> result of a very long lock up time on the PLL of about 60 mS (presumably to 
> improve the the LO phase noise response), though it's usually ok when you 
> tune with the keyboard.
> 
> 73s
> Michael
> G8MOB 
> 
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