Modulation Operation
Giga-tronics 2500B Series Microwave Signal Generators
Page 66
Operation Manual, Part Number 34737, Rev C, June 30, 2011
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Table 26: Generate an Externally Pulse Modulated Signal
Generate an Externally Pulse-Modulated Signal
Step
Action
1.
Perform steps 1 through 10 of the procedure Generate a CW Signal on page 24 to set the frequency
and power level of the carrier.
2.
Connect a TTL pulse source to the PULSE IN/PM TRIG IN connector on the rear of the instrument, and
set it for the following characteristics:
Pulse width = 1 ms
Pulse repetition interval (PRI) = 2 ms
3.
Press
to display the PM Main menu, then press
PM Ext Menu.
4.
Select
PM, and use
or press
PM again to set PM to On (as
indicated on the display).
5.
Select
Input Polarity, and choose the appropriate polarity setting using
.
NOTE:
With an Active High setting, a TTL high level at the PULSE IN/PM TRIG IN connector turns on the
carrier at the RF output.
With an Active Low setting, a TTL high level at the PULSE IN/PM TRIG IN connector turns off the
carrier at the RF output.
6.
If you want to delay the signal at the PM SYNC OUT connector on the rear of the 2500B:
Select
Sync Out Delay, and enter the desired sync pulse delay setting using the numeric
keypad,
, or
.
Limits of delay:
≥ 50 ns; ≤ 10 ms
7.
If the RF ON indicator is not lit, press the RF ON button to enable the RF output (see Figure 3 on page
11).
NOTE:
When the RF output is enabled, the RF ON indicator is blue.
8.
Verify that the Unleveled indicator is not illuminated.
NOTE:
If the Unleveled indicator is lit, then the combination of output power level, power offset,
power slope, and step attenuator mode (if applicable) is set inappropriately, and the RF output is
unleveled. Adjust the combination of settings until the Unleveled indicator turns off.
End of Procedure
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PM
