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and 3800 kHz (200 on the KWM 2/2 \ dial) The hairline indicator should be vertical and in the dial window If there is no end-point spread but the hairline is slanted to left or right loosen the setscrews on the dial hub and slip the dial mechanism on the oscilator shaft until zero beat occurs with the hairline vertical

If there is end-point spread correct it as follows before correcting a slanting hairline.

  1. Zero beat the KWM-2/2A with the l00-kHz calibrator sigt at.3.800 kHz and set KWM2/2A hairline right on 200.

  2. Zero beat the KWM-2/2A with the 100-kHz caiibrator signai at 3600 kHz. Note difference in kHz between hairline and 0 on KWM-2/2A dial (for example -1.5 kHz).

  3. Without moving hairiine move dial to opposite side of 0 by an amount equal to frequency difference noted ahove (for example, +1.5 kHz).

  4. Adjust L302 for zero beat. It is located on top of vfo can.

  5. Set KWM-2/ 2A Hairline over 0.

  6. Check zero beat at 200 on dial (3800 kHz). If zero beat does not occur at exactly 200 repeat steps a through e.

  7. If after adjustment of end points hairline is not vertical in dial window loosen setscrews on dial hub and move dial with respect to the oscillator shaft so that zero beat occurs with end points (0 and 200) set at center.

  8. Atter these adjustments of vfo calibration check vfo sideband frequency shift adjustment according to paragraph 4.6.4.

4.5.11 VFO Dial Centering

  1. Tune the KWM-2/2A lo 14.3 MHz LSB and set function switch to CAL.

  2. Tune the KWM-2/2A to zero beat.

  3. With the hairline vertical 100 should be exactly under the hairline. If not loosen the two setscrews on the dial hub (accessible from the bottom of thc chassis with the cabinet removed), and set 100 exactly under the hairline.

  4. Retighten the setscrews.

  4.5.12 VFO Overtravel

  1. With thc hairline vertical turn the main tuning dial to the end stop past 0.

  2. Note the overtravel between the hairline and 0

  3. Turn the main tuning dial to the end stop past 200, and note the overtravel.

  4. If the overtravel is not equal loosen the two setscrews in the vfo end-stop collar (accessible from the bottom of the chassis with the cabinet removed).

  5. Set thc main tuning dial for half the total difference and tighten the setscrews.

  6. This completes the field alignment of tile KWM-2/2A.


4.6.1 Laboratory allignment

Laboratory alignment of the KWM-2/2A is perforrned only when extensive component replacement has taken place or when the KWM2/2A is being placed in service after a long period of storage. These adjustments should be performed by a skilled technician. Laboratory alignment requires the KWM-2/2A to be removed from its cabinet. Refer to paragraph 4.1 for removal instructions.

4.6.2. Test Equipment Required

Test equipment required for laboratory alignment of the KWM-2/2A are a 50-ohm 100-watt dummy load; a receiver with a 100-kHz crystal calibrator and an S-meter; an rf signal generator with a calibrated output attenuator; and a vtvm with an rf probe.

4.6.3 Transmitting 455-KHz IF Alignment

  1. Disable thc screen circuit of the pa tubes by unsoldering one end of the jumper between PA DlSABLE jacks J5 and J6. Remove V301 from its socket.

  2. Connect an rf vtvm from pin 2 of V5 to ground .

  3. Set OFF-ON-NB-CAL switch to ON. Set EMISSION switch to TUNE. Turn MIC GAIN off.

  4. Any voltage reading on the vtvm is due to carrier. Roughly adjust carrier balance

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