Racal Instruments RA-117 User Manual page 13

(13) Set KILOCYCLES scale to the required frequency and critically tune for zero
beat in order to centralize the signal within the I.F. pass-band.
(14) Adjust R.F. TUNE for maximum signal (or noise). For optimum c.w. reception,
"off-tune" the B.F.O. to produce an acceptaple beat note.
(15) Set the A.F. GAIN to its maximum clockwise position and adjust the output level
with the R.F./I.F. GAIN control.
(16) For m.c.w. or voice reception, switch B.F.O. off.
(17) Set the SYSTEM switch to A.V.C. if required.
(18) Set BANDWIDTH for optimum reception.
"S" METER
8. The "S" meter should be correctly set to zero.
9. With no antenna connected, set the R.F. ATTENUATOR to MAX. Set the SYSTEM
switch to A.V.C. Turn the R.F./I.F. GAIN control to the maximum clockwise position.
NOTE: Unless the R.F./I.F. GAIN control is in the maximum position, the "S" meter
calibration is upset.
10. Remove the plated cap below the meter. Adjust the setting of the balance control
(accessible through the hole in the panel) by means of a screwdriwer until the meter
reads zero.
Operation 13