Tektronix 1L30, Instruction Manual

Page: 88 / 129

C alibration— Type 1L30
Fig. 6-32. Oscillator assembly removed and
positioned
ready for
calibration.
7. Adjust the power output probe penetration and orien­
tation for approximately 1 V peak to peak into 50 f2 for both
output signals as indicated on the dual trace sampling os­
cilloscope system. Tighten the probe set screws at this point.
8. Tune the oscillator throughout its range. Check the
mechanical function for smoothness of operation. If there
is any binding, loosen the set screws and realign the tun­
ing choices. Check the electrical operation, for constant os­
cillation with no dead spots or backlash. Output power
should remain fairly uniform and within 0.75 V to 1.5 V peak
to peak throughout the tuning range.
If dead spots are noticed at either end of the ’ tuning
range, try adjusting the Varactor a n d /o r the pick-off probe.
If backlash is present, try adjusting the outer choke position.
All electrical adjustments interact; therefore, their effect
should be checked throughout the tuning range before pro­
ceeding with the next adjustment.
CALIBRATION
1. Calibrate High Frequency End
a. Tune the frequency meter to 650 M H z. (The 3rd har­
monic will bq. used to set the oscillator frequency.)
b. Tune the oscillator to a frequency of 1950 M H z as
indicated by a beat mode signal on the frequency meter.
6-31