Uniden
Grant LT
Documentation Project
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PLL Alignment
ADJUSTMENT OF PLL AND OSCILLATION CARRIER (Refer to Fig. 2)
Fig. 1 Connections of PLL Carrier Oscillations Adjustments 1. Initially
connect unit to be adjusted as shown in Fig.1. Next adjust each knobs
as follows: 2. Set Channel
Selector to 40CH Adjust oscilloscope to DC range and connect "+"
Probe to TP1 and "-" to L22 Jumper. Adjust L19 so that voltage
of TP1 becomes 3.5V. Moreover, check when adjustment is completed, change
Channel Selector to 1CH and the voltage of TP1 should be 2V or more. 3.Connect Oscilloscope to TP2 and adjust L21 to its peak. 4. Connect Oscilloscope to TP3 and adjust L20 to its peak 5. Adjust L59 by similar connection of (4) to obtain within 34.9865MHz +/-20Hz as will be indicated by frequency counter, then set Mode switch back to "AM". 6. Change moode switch to "AM" and adjust L23 to obtain within 34.985 +/-20Hz NOTE: BEFORE ALIGNMENT SET VR1 VR2 TO MINIMUM CURRENT, ROTATE VR1 (CCW) VR2 (CCW) and VR6 (CCW). 7. Change Mode
switch to LSB and adjust L22 to obtain within 34.9835MHz +/-20MHz as to
be indicated by freq counter. 8. Convert PTT switch to TX and set the unit to the same mode. Adjust VR5 to within 34 9835MHz +/-20Hz and then set PTT to RX mode. 9. Convert Mode switch to USB, connect "+' Oscilloscope Probe to TP5 and '-' to L22 ,jumper, and adjust CT2 to within 7.8015MHz +5/ -0Hz to be indicated by freq counter. 10. Convert
Mode switch to LSB and adjust L30 to obtain within 7.7985MHz +0/-5Hz as
to be indicated by freq, counter. 12. When above adjustment are completed, align once more (5) - (11) to check it property completed. FIG. 2 PLL PORTION |
Disclaimer: Although the greatest care has been taken while compiling these documents,
we cannot guarantee that the instructions will work on every radio presented.