TB 9-6625-1999-35
15. RF Output,
Response and Attenuator Accuracy
a. Performance Check
(1) Connect true rms voltmeter to RF OUT 50 Ω.
(2) Position controls as listed in (a) through (c) below:
(a) MODULATION SELECTOR switch to CW.
(b) ATTENUATOR switch to 1.0 VOLTS.
(c) ATTENUATOR VERNIER control for a 0.9 V indication on R.M.S. VOLTS meter.
(3) Set RANGE switch and adjust FREQUENCY controls throughout all frequency
ranges up to 10 MHz while maintaining 0.9 V indication on R.M.S. VOLTS meter. If true
b below.
(4) Connect measuring receiver to RF OUT 50 Ω.
(5) Perform technique of step a (3) above for the remaining frequencies and ranges.
If measuring receiver does not indicate between 0.8 and 1.0 V throughout frequency range,
perform b below.
(6) Position controls as listed in (a) through (c) below:
(a) MODULATION SELECTOR switch to CW.
(b) RANGE switch to 19MC-65MC.
(c) FREQUENCY dial to 65MC.
(7) Adjust ATTENUATOR VERNIER control while observing R.M.S. VOLTS
meter. Meter pointer will sweep full range of meter.
(8) Set ATTENUATOR switch to +20 DBM.
(9) Adjust ATTENUATOR VERNIER control for a 0 dBm indication on R.M.S.
VOLTS meter. Measuring receiver will indicate between 19 and 21 dB.
NOTE
If necessary, adjust ATTENUATOR VERNIER control to
maintain a 0 (zero) DBM indication on R.M.S. VOLTS meter
during remainder of check.
(10) Repeat technique of step (9) above for ATTENUATOR switch settings in
table 4. Measuring receiver will
indicate within
limits specified. If
not, perform b below.