[Premium-Rx] Fwd: WJ Tech Notes

[John P Ceresole]

Dear Greg/Ian

>Does anyone out there have any information on the WJ-1840/TN-118 Tuner 
>front end?
>
>I know that it tunes 0.5 to 18 GHz.  It will run from 115 or 230 Vac.
>
>I have traced a block diagram of the unit - the RF part anyway it seems to 
>tune in 2 ranges 0.5 to 8 GHz and 8-18 GHz (It has a tuned YIG filter that 
>covers that range) and the other path goes through an in-line bandpass 
>filter tuned by 9 screws .  It has a YIG driver board that has about 20 
>adjustable pots on it - most likely the D/A converter - driver and some 
>logic boards - probably for a 16-bit remote frequency set .  There is also 
>a 10.1 GHz fixed frequency oscillator which appears to feed a 2nd Mixer to 
>give the 21.4 MHz? IF.
>
>This unit was used as a detector for 1-18 GHz EMC emissions in the test 
>lab where I used to work however they unfortunately do not appear to have 
>kept the manual for it. As far as I know it was never used in the last 20 
>years and gathered dust in all that time.

Any info will be gratefully received.

Best regards

John G8BSD