SECTION X
Appendix
Page 10 - 4

    1. Ground the transceiver PTT jack.

    2. Adjust the spectrum analyzer two tone generator control to obtain a 6 db ALC indication on the transceiver meter.

    3. The radio set control WATTMETER shall indicate 500 wats minimum.

    4. Repeat the procedures given in (1) through (9) above with the amplifier and transceiver adjusted for operating frequency of 7.2 MHz, 14.3 MHz, 21.3 MHz, and 28.6 MHz.

  2. ALC Overide Margin Test.

    1. Connect the equipment as outlined in paragraph 10-4 and as shown in figure 10-1.

      NOTE

      The radio set control is not required for this test. Connect the AM-3979/FRC-93 RF OUTPUT connector direct to J1 on the dummy load and remove connection from J3.

    2. Adjust the amplifier and transceiver for 14.3-MHz frequency as outlined in paragraphs 2.1, 2.2, and 2.3.

    3. Set the transceiver PLATE-GRID-ALC switch at ALC.

    4. Set the dummy load REMOTE-DUMMY LOAD switch at DUMMY LOAD.

    5. With the spectrum analyzer frequency output A at 1.0 kHz frequency output B at 1.9 kHz, set the output level for minimum.

      CAUTION

      Do not apply RF output to the dummy load for more than 30 seconds at a time. To stop transmitting, remove ground from PTT jack. .

    6. Ground the transceiver PTT jack

    7. Adjust the spectrum analyzer two tone generator output level until the ALC threshold is reached as observed on the transceiver meter.

    8. Disconnect the ALC line connected in paragraph 10-4c and set the RF amplifier power ON-OFF switch to OFF.

 

    1. Repeat the procedure given in (7) above. Transceiver meter indication recorded in this procedure shall not be less than the indication recorded in (7) above.

  3. Noise and Distortion Test.

    1. Connect the equipment as outlined in paragraph 10-4 and as shown in figure 10-1.

    2. Set the transceiver SSB-CW switch to SSB.

    3. Adjust the amplifier and transceiver for 3.9-MHz operating frequency as outlined in paragraphs 2.1, 2.2, and 2.3.

    4. Set the transceiver PLATE-GRID-ALC switch to ALC.

    5. Set the dummy load REMOTE-DUMMY LOAD switch to DUMMY LOAD.

    6. With the spectrum analyzer frequency output A st 1.0 kHz and frequency B at 1.9 kHz signal, set the output level for minimum.

    7. Adjust the spectrum analyzer two tone generator control until the ALC threshold is reached as observed on the transceiver meter.

    8. Adjust the SWEEP-RATE and MAIN TUNING for spectrum display centered at 3.9 MHz.

    9. Set the IF ATTEN to 20 DB. Adjust the INPUT ATTENUATOR switches to bring the highest pip on the calibrated screen toslightly above 0 db. Adjust the GAIN control to bring the highest pip to prcisely 0 db.

    10. Measure and record the third and fifth order harmonic distortion products. Distortion amplitude shall not be less than 30 db below input level.

    11. Remove the PJ-068 connector. Connect a short-circuited J-068 connector to the PHONE PATCH connector. Measure and record noise level. Noise amplitude shall not be less than 40 db below input level.

    12. Repeat the procedures given in (1) through (11) above with the amplifier and transceiver adjusted for operating frequency of 14.3 MHz.

Add figure 10-1 at the end of section X

Page 10 - 4