MAINTENANCE & ALIGNMENT (continued)

Disconnect the signal generator and the copper wire between SW1 and BC.


(4) 52.5 MHz Selective Filter, T109 ~ T116

Disconnect the input from the oscillator unit at TP101. Connect the sweep oscillator output between TP107 and ground, and the scope between TP109and ground. Set the center frequency of the sweep generator to 52.5 MHz. Adjust T109 to T116 until the scope screen shows the curve shown in Fig. 6.


Fig. 6

Disconnect the sweep generator and scope and reconnect the wiring at TP101. After completion of the above procedures make sure that the RF voltage between TP110and ground is approximately 0.3 to 0.5 volt RMS. If not, repeat procedure.


(5) LOCK Level. VR102

Adjust VR102 until the LOCK lamp turns off at any MHz setting of the MHz dial.


OSC UNIT PB-1523


(1) MHz Setting. T201 ~ TC201


Connect the signal generator to antenna connector SW2and set its frequency to 3.5 MHz. Tune the receiver to the signal generator signal. Adjust T202 carefully until the LOCK lamp turns off at the center of 3 MHz scale on the MHz dial. Set the signal generator frequency to 27.5 MHz and tune the receiver to this signal. Carefully adjust TC201 until the LOCK lamp turns off at the center of 27 MHz scale on the MHz dial. Repeat above procedures until the LOCK lamp turns off at the center of every MHz scale. from 0 to 29 MHz. Disconnect the signal generator.

IF AF UNIT PB-1528


(1) Main Tuning Dial. T403 , TC403


The following alignment should be done after warm-up of the receiver.


Set the dial hair line to the center of the dial window and FINE TUNING control to 12 o'clock position. When the main tuning dial is rotated until it stops over 1000 scale, mark should be within 5 m/m from the hair line.


Set the MODE switch to LSB and Mhz dial to 0. Set the main tuning dial to 1000, then beat tone will be heard. Adjust T403 for zero beat. Set the main tuning dial to 0 and adjust TC403 for zero beat. Repeat above procedures until the tracking is completed.


(2) 2nd IF Tracking, TC401, TC402, T401, T402


Connect the signal generator to the antenna terminal SW2 and sct its frequency to 7.1 MHz. Tune the receiver to the signal from the signal generator. Set the output voltage from the signal generator for S-3 reading on S-meter. Adjust TC401 and TC402 for maximum S-meter reading. Set the signal generator to 7.9 Mhz and tune tlw receiver to 7.9 MHz signal. Adjust TC401 and T402 for maximum S-meter reading. Repeat these procedures until the tracking is completed.


(3) 3rd IF, T404, TC405


Set the signal genenitor to 7.5 MHz and tune the receiver to this frequency. Adjust T404 and T405 for maximum S-meter reading. Adjust signal level so as not to satulate.


(4) S-meter Sensitivity, VR401


Set the output level of the signal generator to 100 dB. And tune the receiver for maximum S-mcter reading. Adjust VR401 for S-meter full scale.

Disconnect the signal generator.


(5) BFO Frequency, T406, TC404


Connect a frequency counter to TP405. Set the MODE switch to LSB. Adjust T406 for 457 kHz on the frequency counter reading. Set the MODE switch to USB/CW and adjust TC404 for 453 kHz.



Return to FRG-7 Index Updated 21 June, 2001 Maintained by Kent Walker