HP 3336A Operating Manual page 28

Model 3336A/B/C
3-25. 10 MHz OVEN OUTPUT (Option 004).
3-26. This output is available only on instruments equipped with Option 004. Option 004
is a temperature stabilized crystal oscillator with an aging rate specified at +5 x 10- per
week after 72 hours of operation. Option 004 is connected to the instrument with a BNC
to BNC adapter, -hp- part number 1250-1499, connecting the 10 MHz OVEN Output to the
EXT REF Input. The EXT REF annunciator will be on continuously when the instrument
and Option 004 (or any frequency standard) are phase-locked together. If they are not locked,
but a signal is present, the annunciator will flash on and off.
3-27. To reduce the warm-up time and realize the maximum performance from an instru-
ment equipped with Option 004, always leave the instrument connected to a power source.
Power is maintained to Option 004 whenever the instrument is plugged in. The warm-up
time for an instrument equipped with Option 004 is 20 minutes if power has been interrupted
for less than 24 hours. If, however, power is interrupted for longer than 24 hours, it may
take as long as 72 hours before Option 004 will meet its aging rate specification.
3-28. The signal at the 10 MHz OVEN Output is a 0 dBm (50 ohms) square wave and is pre-
sent when the Model 3336 is connected to a power source.
3-29. REF OUT (Frequency Reference Output).
3-30. This output supplies a 1 MHz, 0 dBm (50 ohm) square wave derived from the Model
3336's frequency reference. When this signal is applied to the external reference input of a
compatible instrument, the reference oscillator of both instruments will be phase-locked
together.
3-31. MANUAL PROGRAMMING.
3-32. Programming the Model 3336 from the front panel can be done in two ways. The
value of the operating parameter may be set exactly using the Entry keys and the
Number/Units keyboard, or the value can be modified using the Tuning Knob in the Modify
group.
3-33. To exactly set the value of any operating parameter:
1. Press the key associated with the desired operating parameter (the light in the center of
any Entry key indicates the active entry parameter).
2. Press the exact number sequence, including decimal point and minus sign, of the value
to be assigned.
3. Press the appropriate Units key to execute the entry.
3-34. There are two operating rules to be aware of when modifying frequency.
1. If the last frequency entered with the Number/Units keyboard is within the specified
frequency limits of the selected output, the frequency can be modified, using the Tuning
control ONLY within those frequency limits.
2. Frequency can be modified from 10 Hz to 20.999 999 999 MHz if the last frequency
entered with the Number/Units keyboard is outside the specified frequency limits of the
selected output.
Operation
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