[Premium-Rx] WJ-8645B - what is it ?

[Geoff Greer]

   The 8645B is part of a system that was used to fingerprint phones for  
fraud detection.  It works on low band analog.  Every phone, even  
identical models have a unique signature.

Geoff Greer


On Tue, 19 Apr 2005 16:51:43 -0400, Dave Emery <die at dieconsulting.com>  
wrote:

> 	This may and may not be a bit off topic,  but I recently
> acquired from the e-place a WJ8645B computer controlled receiver on a
> card.  It is a fairly recent (1996 ?) RS-232 controlled receiver card
> about 14 inches by 4.5 inches by 3/4 inch thick.
>
> 	I am very curious if anybody out there has any clue as to what
> frequency range this receiver covers and any other details about  it -
> so far web searches have turned up nothing...  and naturally any
> pointers to any kind of documentation would be greatly appreciated.
>
> 	It has a SMA connector marked RF input, a SMB connector marked
> 10 mhz ref input, another SMB connector marked 40 khz IF sample out and
> a full DB-25 male for RS-232 control, plus a DB-15 marked Data output.
>
> 	From various markings it appears to have 40 khz third IF, a  455
> khz second IF and an unclear 1st IF with marked test points for three
> different LO lock indicators for a 1st, 2nd, and third LO.  It also has
> an LED marked RUN/ERROR.
>
> 	It appears to be powered by + 28 volts.
>
> 	Perhaps the oddest marking is TP18, Conversion Counter Out...
>
> 	Superficially this thing appears to be a receiver that dumps
> I and Q samples out the DB-15 connector somehow with a 40 khz DSP
> based last IF.    This would imply a fairly small maximum bandwidth
> (say 15 or 20 khz)... which suggests HF or low VHF...  the seller thought
> it was UHF somewhere (1000 mhz).
>
> 	But it also appears that probably a bunch of these were stacked
> in some kind of array...
>
> 	I suppose I can power it up, supply a 10 mhz reference and see
> what I can do with the RS-232 port, but perhaps someone out there
> actually recognizes this thing and knows about it ...
>



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