Tektronix 067-0532-10 Calibration Fixture Manual page 20

Maintenance--Type 067-0532-01
The output amplitude should remain within 2% of indicated amplitude at
each of the calibrated amplitudes.
Frequency Calibration
Frequency calibration consists of adjusting the inductance of the 3 MHz
oscillator tank circuit. Frequency calibration of the GR 65-500 MHz
oscillator is described in Section 8. All frequency measurements should
be made with the generator output terminated in 50 ohms. (If the output
load termination appears to be significantly different than 50 ohms due
to the input loading of the frequency measuring device, then use a 50 ohm
10X attenuator between the generator and the termination.)
T20: Connect the generator output through a 50 ohm termination
to the frequency counter. Place the bottom cover on the generator.
Adjust T20 for 3.0 MHz within 0.15 MHz.
The output frequency changes slightly with output amplitude, but should
remain within the limits described in Section 1. The frequency accuracy
of the 65-500 MHz oscillator should be within the limits described in
Section 1. Frequency calibration of the GR oscillator is described in
Section 8.
Constant Amplitude Accuracy
65 MHz to 500 MHz Using Power Meter
Connect the generator output through a 10 dB attenuator to the Power Meter
input. Adjust the Power Meter zero to obtain a convenient on-scale refer-
ence amplitude. Vary the frequency from 65 MHz to 500 MHz. The output
amplitude should remain constant within the limits described in Section
1 (2% power variations are equivalent to 1% voltage variations). Repeat
for all output amplitudes.
3 MHz to 500 MHz Using Peak-to-Peak Detector
Use the Peak-to-Peak Detector to verify the 65 MHz to 500 MHz amplitude
accuracy with respect to 3 MHz. Refer to the 067-625-000 Calibration
Fixture Instruction Manual for operating procedures.
This completes the calibration of the generator. If the General Radio
Oscillator requires calibration, refer to Section 8.