Radio Systems TR-6000, Operating Instructions Manual

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R a d i o S y s t e m s , I n c . T R - 6 0 0 0 M a n u a l
P a g e 9
TR-6000 Frequency Change Procedure
1. Set dip switches S1, S2 and S3 for the desired output frequency.
2. Set the output filter jumpers for low or high band.
3. Adjust the power control VR1 to its minimum position.
4. Turn VR10 and VR11 fully counter clockwise.
5. Apply power to the unit.
6. Measure the oscillator frequency at U11 pin 13.
7. Adjust C57 for an oscillator frequency of 10 MHz.
8. Check for the carrier frequency (Test Point A).
9. Adjust VR8 for a 45% duty cycle square wave at U17 pin 5 (Test Point D).
10. Adjust VR9 for a 45% duty cycle square wave at U18 pin 5 (Test Point B).
11. Adjust VR1 for 10 volts on the drain of Q6.
12. Adjust VR7 for 5 volts on the center tap of T3.
13. Adjust C123 for maximum power output.
14. Increase VR10 and VR11 until the bottom half the gates signals of Q8 and Q9 are just below
zero volts (Test Point C & E).
15. Increase VR1 to its maximum position and adjust VR2 for the desired maximum power (Not to
exceed 10 watts).
16. Calibrate the RF power meter with VR13.
17. Apply a -50 dBm, 1 KHz audio signal to J4 +/-.
18. Adjust VR3 fully clockwise.
19. Adjust VR4 for maximum modulation.
20. Turn VR3 counter clockwise to reduce the modulation percentage and re-adjust VR4 for
maximum modulation.
21. Increase the audio generator level to 0 dBm and adjust VR3 to the point just below clipping of
the RF envelope.
22. Adjust VR6 for 90% to 95% modulation.
23. Check the audio frequency response, carrier frequency and RF spectral purity of the unit.
24. Decrease the audio generator level in 10 dB steps and check for at least approximately 80%
modulation down to a -35 dBm level.
25. Calibrate the VU meter to 0 with VR5.
26. Check the carrier frequency and RF spectral purity of the unit.
27. Seal all potentiometers except VR1, VR3 and VR12.
28. Install the top cover.
29. Turn the unit on and re-adjust C123 for maximum power output.