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Table 4-3. KWM-2A Transceiver, Voltage and Resistance Measurements (Cont.)

 

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Voltage at V16 - 2 is 1.8/1.5 Vdc (± 20%) if V16-1is connected to V15 - 2. Refer to =26=> in illustration section.

Voltage at V17 - 6 is -1.5/-1.6 Vdc (± 20%) and resistance is 2.3MW/2200 W if R190 is 2200 W and R211 is not installed. Resistance depends on polarity of ohmmeter. Larger resistance is with positive lead of the ohmmeter connected to ground. Refer to =37=> in illustration section.

Voltage at V17 - 7 is 300/-4 Vdc (± 20%) and resistance is 8500 W /100 KW (± 20%) if R193 is 220 KW, R194 is 470 KW, and CR9 is installed.Resistance depends on polarity of ohmmeter. Smaller resistance is with positive lead of the ohmmeter connected to ground. Voltage at V17 - 7 is 300/-4 Vdc (± 20%) and resistance is 8500 W (± 20%) if CR9 is not installed. Refer to =19=> in illustration section.

Voltage at V17 - 2 is 3.8/0.2 Vdc (± 20%) if R193 is 220 KW, R194 is 470 KW,. Refer to =19=> in illustration section.

4.5 FIELD ALIGNMENT PROCEDURES

4.5.1 Field alignment

Field alignment consists of a few simple adjustments and is intended as a means of restoring peak performance of a working KWM2/;2A. No alignment procedure should ever be performed just for the sake of alignment. Adjustments should be made onl! when there is reason to suspect that performance is not up to standard. All field alignment adjustment points can be reached by raising the cabinet lid and the KWM-2/2A does not have to be removed from its cabinet. Refer to figure 4-1 for adjustment locations.

4.5.2 Test Equipment Required

'I'est equipment required for field alignment of the KWM-2/2A are a 50-ohm, 100-watt dummy load and a receiver with a 100-kHz crystal calibrator and an S-meter.

4.5.3 RF Circuils peaking

  1. Connect dummy load to KWM-2/2A output jack J1. Set KWM-2/2A controls as follows: OFF-ON-NB-CAL to ON, BAND to 28A, EMISSION to LSB, MIC GAIN to OFF, INCREASE LOADING to 50 W and tuning dial to 100.

  2. Afler 6-minule warmup period, set EMISSION switch to 'I'UNE and meter switch to GRID. Adjust MIC GAIN and EXCITER TUNING to

 

  2. produce midscale indication on meter. Set meter switch to PLATE, and dip plate current with PA. 'I'UNING. Reset meter switch to GRID. Peak the four E)28 trimmer capacitors for maximum grid current. Refer to figure 4-1 for trimmer locations.

  3. Set BAND switch to 21.2 and tuning dial to 100. Adjust MIC GAIN and EXCITER TUNING for midscale grid current. Set meter switeh to PLATE, and dip plate current. Reset meter switch to GRID. Peak the four (D)21 trimmer capacitors for maximum grid current.

  4. Set BAND switch to 14.0 and tuning dial to 150. Adjust MIC GAIN and EXCITER TUNING for midscale grid current. Sct meter switch to PLATE and dip plate current. Reset meter switch to GRID. Peak the four (C)14 trimmer capacitors for maximum grid current.

  5. Set BAND switch to 7.0 and tuning dial to 150. Adjust MIC GAIN and EXCITER TUNING for midscale grid current. Set meter switch to PLATE, and dip plate current. Reset meter switch to GRlD. Peak the four (B)7.0 trimmer capacitors for maximum grid current.

  6. Set BAND switch to 3.6 and tuning dial to 100. Adjust MIC GAIN and EXCITER TUNING for midscale grid current. Set meter switch to PLATE, and dip plate current. Reset meter switch to (GRID. Peak thc four (A)3.6 trimmer capacitors for maximum grid current.

  7. Set EMISSION switch to LSB.

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