5-3.
100 MHz VOLTAGE-CONTROLLED CRYSTAL OSCILLATOR (VCXO),
A30 (Cont’d)
19.
Check the level of the 100 MHz harmonics as displayed on the Spectrum Analyzer. Harmonics at
100, 300, 500, 600, 700,
and 900 MHz must be greater than 40 dB down from the 400 MHz signal.
Harmonics at 200 MHz must be greater than 25 dB down from the 400 MHz signal. Harmonics at
800 MHz must be greater than 15 dB down from the 400 MHz signal. If not, repeat step 15.
Table 5-5.
Selection Chart for Attenuator Resistors
Attenuation
(dB3
Resistors (Ohms)
R67
R68
R69
9
9
9
9
9
9
9
9
9
9
Open
825
422
261
215
178
162
133
121
110
Short
6.8
121
17.8
23.7
31.6
38.3
46.4
51.1
61.9
Open
825
422
261
215
178
162
133
121
110
NOTE
HP Part Numbers for resistors may be found in Table 5-5.
20. Set the OUT’s LINE switch to STANDBY. Disconnect equipment from the OUT and reconnect the
two cables. Disconnect the 10 MHz Frequency Standard cable at the rear of the OUT, reconnect
jumper cabled between NT and EXT, and set switch to INT. Set the OUT’s LINE switch to ON.
5-22
Adjustments
HP 8340B/41B