Burst Pulse Alignment

Test Goal

Verify that the burst pulse is present and that its amplitude is sufficient. This test also aligns the burst pulse in the burst pulse sample window.

Test Equipment

KVM connected

Test Procedure

1. Use Ascope to select the desired pulse width at a saved PRF.
2. Enter the TTY setups through dspx.
3. Issue the Mb and turn off burst pulse tracking.
4. Set the transmitter to radiate.

5. Issue the Pb and turn off burst pulse tracking.

   Use the L/R commands to find the burst pulse.

   Use the l/r commands to fine tune the position of the burst pulse in the burst pulse window.

6. Adjust the width of the burst pulse window using the I/i command to be slightly larger than the burst pulse (for example, ~50%).
7. Verify that the burst pulse power is in the range +1 ... -12 dBm per the tabular display on the setup terminal.
8. Record the burst pulse power:

   Pulse width #
   0	______ dBm
   1	______ dBm
   2	______ dBm
   3	______ dBm

9. Repeat the procedure for each pulse width.

If you cannot find the burst pulse, try to detect the burst pulse on an oscilloscope connected directly to the IF burst line (ahead of IFDR10).

On a magnetron radar, if the AFC does not work, the IF frequency may be outside IFDR10 anti-aliasing filter bandwidth. To get it to work you may need to go to manual frequency control. If no burst pulse is detected, an experienced technician must service the radar. If the burst pulse power is too small or large, check the status of the attenuators or amps in the burst pulse signal path. You may need to adjust the gain by installing a fixed attenuator or amplifier.

Checklist