TB 9-6625-003-35
NOTE
Interaction exists between high and low adjustments. Repeat
(1) through (3) above as necessary for best compromise.
28. Frequency and Bandwidth
a. Performance Check
(1) Connect equipment as shown in figure 2.
(2) Position controls as listed in (a) through (e) below:
(a) INPUT SELECTOR switch to XTAL 200Ω.
(b) GAIN control fully clockwise.
(c) VERNIER control fully clockwise.
(d) FREQ control fully counterclockwise.
(e) BANDWIDTH control fully clockwise.
(3) Adjust test oscillator (A9) amplitude for an on-scale indication on TI meter and
fine-tune frequency control for peak indication on TI meter. Frequency counter (A5)
indication will be greater than 1000 Hz. Record frequency counter indication.
(4) Set FREQ control fully clockwise and adjust test oscillator frequency for peak
indication on TI meter. Frequency counter will indicate less than 1000 Hz. Difference
between frequency counter indication and indication recorded in (3) above will be at least
50 Hz.
(5) Adjust test oscillator frequency control until frequency counter indicates 1000
Hz.
(6) Adjust FREQ control for peak indication on TI meter.
(7) Adjust test oscillator amplitude for 0-dB indication on TI meter.
(8) Reduce test oscillator frequency until TI meter indication drops to 1.5 dB on 0 to
10 DB scale. Record frequency counter indication.
(9) Increase test oscillator frequency until TI meter reaches peak indication and
again drops to 1.5 dB.
(10) Record frequency counter indication.
Difference between two recorded
frequencies will be 100 Hz or more.
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