Manual - 8500A Series Peak Power Meter - Giga-tronics
Manual - 8500A Series Peak Power Meter - Giga-tronics
Manual - 8500A Series Peak Power Meter - Giga-tronics
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Operation<br />
See the Non-Volatile Memory discussion in Section 2.17 for more information on<br />
the PPM memory capabilities.<br />
13 Spin Knob The spin knob changes the value of selected parameters. The usability of the knob is<br />
indicated in the display by the appearance of a delta symbol (∆) next to the name of<br />
the parameter of interest. For instance, when in the <strong>Peak</strong> mode, a Cursor Delay entry<br />
will cause the delta symbol to appear next to DLY in the power reading display.<br />
This means that the spin knob can be used to change the Cursor Delay setting.<br />
14 Detector Select<br />
A or B<br />
(8502A only)<br />
15 <strong>Peak</strong>, CW,<br />
Graph<br />
These keys select which channel should display data on the Model 8502A display.<br />
They also tell the instrument which channel a trigger level entry is intended for. In<br />
the CW and <strong>Peak</strong> Modes it is possible to display measurements for either channel A<br />
or B, or both at the same time. In the Graph Mode, only one channel at a time can<br />
be viewed.<br />
These mode keys select whether the PPM will be used for CW or <strong>Peak</strong> power<br />
measurements. GRAPH is used when making <strong>Peak</strong> power measurements to allow the<br />
graphic display of the detected pulse and easy determination of pulse timing factors.<br />
In addition to the readout display indications, the selected mode is identified by<br />
which LED in the center of the PEAK, GRAPH, and CW keys is lit. If the Model<br />
8502A is being used for dual channel operation and all of the mode LED’s are out,<br />
then it is in the Ratio Mode (see the <strong>Power</strong> Ratio Measurement Procedures in<br />
Section 2.10.5).<br />
When the 8502A Ratio Mode is in use, the A and B keys call up a menu so that the<br />
type of signal (CW or <strong>Peak</strong>) can be specified for the selected channel. This is useful<br />
for determining the ratio between a CW and a <strong>Peak</strong> signal. For example, a radar<br />
TWT might have a pulsed output but its input could be CW. To measure its gain, the<br />
<strong>Peak</strong> output would have to be divided by the CW input. The 8502A does this<br />
instantly and automatically.<br />
16 Detector Input These receptacles provide the input from the A and B channel detectors in the<br />
Model 8502A. The Model 8501A has a single input.<br />
17 Calibrator The CALIBRATOR connection performs an amplitude response calibration of the<br />
detector from -30 dBm to +20 dBm, as well as standardizing the absolute power<br />
level readings (see the Self-Calibration Procedure in Section 2.7).<br />
<strong>Manual</strong> No. 20790, Rev C, November 1998 2-9<br />
Superceded by Revision D, March 2009