Make your own free website on
Next Page
Page 4 - 9

  1. potentiometer Rl5 and eapacitor C9 for minimum vtvm indication.
  2. Set MIC GAIN to full on.

  3. Adjust the slug of T1 for peak vtvm reading. Adjust filter input trimmer C54 for peak vtvm reading.

  4. Disconnect vtvm, replaee V301, and reconnect the jumper between the PA DISABLE jacks.

  5. After perfornzing the above procedure, adjust the carrier balanee according to paragraph 4.5.5.

4.6.4 Bandpass IF Alignment

  1. Set OFF-ON-NB-CAL sxviteh to ON. Set EMISSlON s\viteh to TUNE. Iune and load KWN 2A into a dummy load at 14.3 19IHz. Switch meter to GRID position.

  2. Make a swamping tool by connecting a 1000 ohm resistor and a 0.01- F capaeitor in series and connecting clips to their free pigtails. Connect the swamping tool across terminal 3 (secondary winding) of T2 to ground. This terminal is connected to the T2 end of coupling capacitor C25.

  3. Keep grid current to approximately midscale or lower by adjusting MIC GAIN control, and peak the primary of T2. The primary slug for T2 is at the bottom of the can. Use grid current as peak indication.

  4. Remove the swamping tool from the secondary of T2, and connect it across terminals l and 2 (primary winding) of T2 (between pins 1 and 6 of first mixer V5). Peak the secondary of T2 (slug at top of shield can). Remove the swamping tool.

  1. Retune and reload at 14.2.55 MHz. Without swamping any of the tuned circuits, peak L4 for grid current indication.

4.6.5 RF Circuits A1ignment

  1. Adjust all ceramic trimmer capacitors, including the three below the chassis, to one-half maximum capacitance, except as follows: DO NOI change the setting of CARRIER BAL, capacitor, and set 3.8-MHz trimmers C70, C,37, Cl09, and C130 to two-thirds maximum capacitance. Maximum capacitance of these trimmers occurs when the large square notch is set midway between the two mounting screws. Onehalf capacitance occurs with the notch pointed directly at the front or rear of the unit. Two-thirds capacitance occurs with the notch turned off the half-point toward the mounting screws. Refer to figure 4-2.

  2. Conneet the KWM-2/2A output to a 50-ohm dummy load. Set the dial to 100, BAND switch to 3.6, and EXCITER TUNING control to 2.1 on the logging (lower) scale. Set meter switch to GRlD and EMISSION switch to LOCK


    Keep MIC GAIN setting low to protect pa. Check frequently to be sure the pa is resonated.

  3. Adjust MIC GAIN control for approximately 1/4-scale grid current. Tune and load the pa into the dummy load.

Figure 4-2

Next Page