
Tuning the HP 8662A or HP 8663A
The HP 8662A or HP 8663A can be used as the VCO in a phase
lock loop using three different configurations. These configurations have
different tuning characteristics and different levels of noise performance.
The HP 8662A and HP 8663A have the best noise performance when
tuned with EFC (electronic frequency control).
EFC tunes the internal HP 8662A/63A internal 10 MHz Reference Time
Base. The internal time base tunes approximately 0.05 Hz/V over ±10V
at 10 MHz. To calculate the VCO Tuning Constant using EFC, multiply
0.05 Hz by the 10 MHz multiple of the output frequency. For example, if
the output is set to 900 MHz the VCO Tuning Constant would be:
90 x 0.05 Hz = 4.5 Hz/V
Using the full Voltage Tuning Range of ±10V would result in a Peak
Tuning Range of 45 Hz. (The internal time base typically has a tuning
constant greater than 0.05 Hz/V.) Tuning with the EFC input will
not degrade the noise performance of the HP 8662A/63A. The noise
performance is specified for this mode.
6-8 RF Sources
Commenti su questo manuale