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4.7.2 Resistor R140

  1. Connect equipment as reqiuired to perform ALC zero adjustment, paragraph 4.5.6.

  2. Perform ALC zero adjustment.

  3. Connect a precision multimeter to the PHONE PATCH terminals and measure the 2-tone generator input.

  4. Set the MIC GAIN control fully clockwise, and increase the 2-tone .input level until ALC threshold is indicated on the KWM-2/2A meter (set at ALC position).

  5. If the multimeter indicates more than 5mV input to the PHONE PATCH terminals, recheck the KWM-2/2A alignment.

    Note

    If alignment appears normal and more than 5 mVac is indicated, select and replace R140 with a value to give an .ALC threshold between 2- and 5-mV 2-tone input.

  6. f. If the multimeter indicates less than 2 mV, select and replace R140 with a value to give an ALC threshold between 2- and .5 mV 2-tone input.

4.7.3 Resistor R162

  1. Turn on the KWM-2/2A and set to receive LSB

  2. Select value of R162 to provide 1.25 Vac at V2A-9.

4.7.4 Resistor R158

  1. Connect equipment as required to perform receiver 456-kHz if alignment procedures, paragraph 4.6.16.

  2. Set the rf signal generator to 100 µV. Select and replace R158 with a value resistor that provides a KWM-2/2A meter reading of S8 to S9 + 10.

4.7.5 Resistor R161

  1. Connect eguipment as required to perform rf circuit peaking procedures, paragraph 4.5.3.

  2. set EMISSION switch lo TUNE (any frequency) and PA LOAD conlrol to 50 ohm and tune the KWM-2/2A.

 

  3. Set EMISION switch to LSB and MIC GAIN control to OFF set meter switch to GRID

  4. Set EMISSlON switch to LOCK, and adjust the MIC GAIN control for grid current threshold, then set meter switch to PLATE.

  5. Connect an ammeter in serics with J 13-2 and +800-Vdc power source. Check that ammeter reads 220 mA. The KWM- 2/2A meter should read 230 mA. (KWM-2/2A meter reads cathode current approximately 10 mA Of cathode current is screen current.)

  6. If KWM-2/2A metcr does not read 230 mA, select and replace R161 with a value resistor that provides 230-mA current.

4.8 DlAL CORD REPLACEMENT (Refer to figure 4-4.)

Note

Be careful not to damage the bandswitch cord or loading capacitor cord. Frayed dial cords should be replaced. Frayed cords can providcerf loops that might affect transceiver operation.

4.8.1 Band Switch Cord

  1. Remove the power cable frolll the KWM-2/2A

  2. Using a knife blade or small screwdriver pry open the tabs. and remove the broken or defective cord from the two band-switch pulleys. The band-switch pulleys are located near the front panel, one above and the other below the chassis. Loosen the idler pulley so it will not be in the way during restringing.

  3. Placc the BAND switch in position 1A, and rotate the pa band-switch pulley to the approximate position shown in figure 4-4.

    Note

    The band detent pulley may not be in thc exact same position shown in figure 4-4. Do not reposition this pulley, but assumc it to he in the correct position during restringing.

  4. Replacc the old cord with threc feet (9.144 dm) of new cord. Collins part number 432-1009-00. When ordering dial cord, be sure

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