[Premium-Rx] Need help with filter assignment on Racal

[Charles Steinmetz]

Ed wrote:

> I have a Racal RA-6793 which has the following mechanical filters:
> 6.0 kHz BW, 3.20 kHz BW, 1.0 kHz BW, 0.30 kHz BW, LSB - 2.95 kHz BW, USB - 2..95 kHz BW.
> The display is not showing them correctly. There are 7 filter slots: FL 1-6 plus FL-7, which is jumpered for 16 kHz. How do I assign these?

The filter installation/setup/verification procedures are detailed in 
Paragraphs 3.3.1 through 3.3.1.1 on pages 3-8 through 3-10 of Racal 
Technical Manual T.M. 6793A, dated November 1985.

Note that the LSB and USB filters must be in Positions FL-1 and FL-2, 
respectively.

Also note that because the 6793 feeds all filter inputs in parallel and 
switches only the filter outputs with diode switches, leakage from the 
jumper in Position FL-7 allows considerable out-of-band energy to bypass 
the narrower filters.  I strongly advise removing the jumper to improve 
the selectivity of all the narrower filters.

Best regards,

Charles