HP 3336A - Page 27

Operation Model 3336A/B/C
3-18. Level Limits.
3-19. Every front panel output has an amplitude range of 79.99 dB with 0.01 dBm resolu-
tion. The absolute maximum and minimum amplitudes, however, differ from output to out-
put. The upper and lower output level limits for each output are:
Output Lower Level Limit Upper Level Limit
50 ohm unbal — 71.23 dBm + 8.76 dBm
75 ohm unbal — 72.99 dBm + 7.00 dBm
124 ohm bal — 78.23 dBm + 1.76 dBm
135 ohm bal — 78.23 dBm + 1.76 dBm
150 ohm bal — 78.23 dBm + 1.76 dBm
600 ohm bal —72.99 dBm + 7.00 dBm
NOTE
When changing from one output to another, expect a level change
equal to the difference of the output level limits. For example,
when changing from the 50 ohm to the 75 ohm output, the output
level will decrease 1.76 dB. Conversely, expect the level to increase
when changing back to the 50 ohm output.
3-20. SYNC OUTPUT.
3-21. This rear panel output supplies a TTL level square wave for synchronizing other in-
struments to the signal from any front panel output. The phase relationship between the
front panel signal and the Sync signal is always constant with the transition between levels
occurring at the zero-crossing of the front panel signal.
3-22. When the SYNC Output is terminated with 50 ohms, the Sync Signal levels are:
Low Level = = +0.2 V
High Level = = +1.2V_
NOTE
If the SYNC Output is connected to a high impedance load, the
voltage levels will be approximately twice the values given. The im-
proper termination of a 50 ohm system, however, may cause ring-
ing at the positive and negative transitions.
3-23. EXT REF INPUT.
3-24. The Model 3336’s reference oscillator may be phase locked to an external frequency
standard, transferring the standard’s frequency accuracy and aging rate to the Model 3336.
The input signal level must be: from 0 dBm to + 20 dBm (50 ohm) and the frequency must
be within 10 parts per million of 10 MHz or a submultiple of 10 MHz down to 1 MHz (10
MHz, 5 MHz, 3.3333 MHz, 2.5 MHz..... 1 MHz). The EXT REF annunciator will light con-
tinuously when the instrument and an external frequency reference are phase-locked
together. If they are not phase-locked but a signal is present, the annunciator will flash on
and off.