Manual - 8500A Series Peak Power Meter - Giga-tronics

Series 8500A Peak Power Meters
1. Connect the channel A detector to the RF source (port) that is believed to be generating a pulse
before the second source (port) to be measured (i.e. Measurement Port 1). If the pulses of the
two sources are coincident, use either port.
2. Connect the channel B detector to the second source (port).
3. Select the Graph Mode in channel A, and press [GRAPH] to Autoscale.
4. After the pulse has been successfully Autoscaled, set the Cursor to the desired measurement
point.
5. Make a note of the Window and Cursor Delays. (The Start Delay will be 0.0000 ns after
Autoscaling.)
6. Press Detector Select [B] to switch to the channel B Graph Mode.
7. Set the Window and Cursor Delays to the same values as were noted in Step 5. If the pulse is not
visible on the readout, gradually increase the Start Delay until the entire pulse is on the screen.
8. Set the Cursor Delay to the point on the pulse where it is desired to take a measurement. Channel
A and B Cursors should now be placed wherever dual channel readings are to be taken. This can
be verified by pressing Detector Select [A] or [B] as necessary to check that the Cursors are
properly positioned.
9. Select the Peak Mode of operation by pressing [PEAK].
10. Select Dual Channel operation by pressing Detector Select A. Make sure that the LEDs in the
center of the Detector Select A and B keys are lit. This signifies that the PPM is in the Dual
Channel Mode. The display should be similar to the following:
A: +0.65 dBm, 30.600 ns
B: -4.65 dBm, 39.700 ns
FREQ = 1.00 GHz, PEAK
2.10.4 Peak, CW Measurements
If it is desired to measure Peak power on one channel and CW on the other channel, the procedure is the
same as when measuring Peak Power on both channels with some minor differences. These differences
are:
1. The channel used to make the Peak power measurement determines the triggering of the PPM.
For low amplitude signals (below -20 dBm in the Peak Mode), use external triggering.
2. It is not necessary to use the Graph Mode or any Delay settings on the channel that will be
measuring CW as the power will be continuous, and it makes no difference at what time the CW
is sampled.
3. Even though one channel is displaying CW power, the PPM operates as though both channels
were in the Peak Mode. CW averaging has no effect on the reading. The rate at which the RF is
sampled and averaged is determined by the characteristics of the Peak power channel.
2-34 Manual No. 20790, Rev C, November 1998
Superceded by Revision D, March 2009