HP (Hewlett-Packard) HP 85660B ユーザーズマニュアル

The 100 MHz VCXO Tune Voltage can be measured at 

 However,

the voltage levels will be slightly lower than those listed above.

Table 5. Integrating Amplifier Voltage Levels

de Voltage Levels

Pin 1

Pin 2

0.0 (locked)

Pin 3

0.0 (no 10 MHz) Ref.

 (no 100 MHz) VCXO

Pin 4

Pin 5

Pin 6

+o.o

25

E m i t t e r  

Base

Collector Gnd

E m i t t e r  

Base

Collector

-6.6

The output of the Lock Indicator Sampler is compared to a reference of -0.4 V by
comparator U5. The output of U5 is high for any unlocked condition. 

 limits the output

voltage (HULR) to approximately 4.64 V.

This can be checked by disconnecting the 10 MHz input at 

 (gray/white cable) and

measuring the output of U5. With the loop unlocked (10 MHz removed), this output should
be approximately 4.64 V.

 7