HP 5335A - Detailed Measurement Functions

Operation and Programming
3-93. DETAILED OPERATING INSTRUCTIONS
3-94. The following paragraphs provide detailed operating information. Within a specific
function mode, (e.g., FREQ A, PER) a considerable amount of flexibility is present for both
the type of input signal and measurement technique. The intent of the following paragraphs is
to provide an instructional discussion, which demonstrates the user control flexibility for each
major function mode. These operating guidelines should assist in making the most useful and
accurate measurement possible.
3-95. FREQ A
3-96. The FREQ A mode makes measurements on frequencies up to 200 MHz through the
Channel A INPUT. In this function the input is prescaled by two, however, there is no loss
of resolution. On power-up, the 5335A assumes the FREQ A function with the GATE MODE
in NORM. For a cwsignal connected to INPUT A (and within the restrictions set by the input signal
conditioning controls) the counter is self-arming, and measurements begin immediately.
The displayed resolution is adjusted with the GATE ADj control.
3-97. Suppose you need to measure a pulsed frequency. Assuming no transients occur before
the pulse, the frequency of this signal is measured by setting the GATE MODE to FAST, and
adjusting for a gate time just under 200 ps. The INPUT A controls are set to ac coupling,
separate, with the trigger level control at PRESET. The counter is armed by the signal, and the
gate opens automatically just after the start of the pulse.
3-98. To measure the frequency at various points along a chirp, use the 5335A ; s arming
capability. By setting the START ARM slope to positive and the STOP ARM slope to negative, and
then turning EXT ARM ENABLE on, the frequency at various points can be measured. Use an
external timing generator to produce the external arm signal.
ARMING SIGNAL 2
3-99. If the timing generator cannot provide a pulse width of the appropriate width, the STOP
ARM can be turned off, which lets the counter stop arm itself. With this setup, you can specify
any gate time from 100 ps on up. With GATE MODE in MIN, the counter will measure the fre¬
quency based on two periods of the input.
3-20
Model 5335A