[Premium-Rx] DSI R-1250 on E-bay

[John P Ceresole]

Hi Guys

This Receiver is actually a tempest receiver and was used in laboratory 
conditions (mainly) with on-site capabilities.  Someone asked about it's 
sensitivity(ies) - it has a quoted NF (Noise Factor) of 10 dB which if you 
follow the link: 
http://www.kongsfjord.no/data_sheets/Watkins-Johnson/Watkins-Johnson%208940B%20data%20sheet.pdf 
gets you to the WJ-8940B - a similar receiver (but in my view much better 
which I have had the pleasure of using over the last 22 years.)  On the 4th 
page of the leaflet it gives the typical sensitivities of the WJ with a 
similar NF so you can work out the sensitivity for each bandwidth which are 
similar to the DSI's.  These don't have optimised filters/product detectors 
for SSB.

The R-1250 runs very hot and is none too reliable as a result - it's also 
very heavy for it's size (the 8940B is even heavier) but it does make a 
very good door stop (I have used an R-1250 for this purpose).  The R-1250 
is controllable via GP-IB.  The tuning knob position is not the most 
ergonomic I have ever seen especially when you have to use it up to 7-8 
hours/day during testing.

If anyone is interested I have the sales blurb for the Rx as well as the 
accessories (1-18 GHz downconverter, comb generator and software for (I 
think) the R-9000 system - an automated data acquisition system that uses 
the R-1250.

Apart from that it's not a bad piece of kit.

Best regards to you all

John