Telex Radiocom BTR-200 Series Service Manual page 23

4. Connect the signal generator to the Receive
Antenna jack. Set the deviation to
±
3 KHz at
I KHz. Refer to the chart and select the channel
3 frequency.
5. Connect the AF voltmeter, distortion meter, and
SINAD meter to U421 pin 1.
6. Adjust VR421 to maximum counterclockwise.
7. Adjust VC301, VC302, VC303, VC304,
VC305 and VC306 for best SINAD.
8. Increase signal generator output to I m V.
9 Adjust L422 for maximum audio.
lOA. Version I: Adjust L421 and L422 for minimum
distortion.
lOB. Version 2: Adjusut L421, L422 and L423 for
minimum distortion.
11. Adjust VR420 for 140 mV of audio.
12. Set the signal generator output to I !-tV.
13. Adjust VR421 fully clockwise, then turn it
counterclockwise until the number 3 LED on
the front panel just comes on.
14. Set the signal generator to the channel I fre-
quency and increase the output to 1 m V.
15. Move the audio hook up to U321 pin I.
16. Adjust L322 for maximum audio.
17A. Version I: Adjust L321 and L322 for minimum
distortion.
17B. Version 2: Adjust L321, L322, and L323 for
minimum distortion.
18. Adjust VR320 for 140 mV of audio.
19. Set the signal generator output to I !-tv.
20. Adjust VR321 fully clockwise, then turn it
counterclockwise until the number I LED on
the front panel just comes on.
21. Set the signal generator to the channel 2 fre-
quency and increase the output to I mV.
22. Move the audio hook up to U371 pin I.
23. Adjust L372 for maximum audio.
24A. Version I: Adjust L371 and L372 for minimum
distortion.
24B. Version 2: Adjust L371, L372, and L373 for
minimum distortion.
25. Adjust VR370 for 140 mV of audio.
26. Set the signal generator output to 1 !-tv.
27. Adjust VR371 fully clockwise, then turn it
counterclockwise until the number 2 LED on
the front panel just comes on.
28. Set the signal generator to the channel 4 fre-
quency and increase the output to I m V.
29. Move the audio hook up to U471 pin 1.
30. Adjust L472 for maximum audio.
31 A. Version I: Adjust L471 and L472 for minimum
distortion.
31 B. Version 2: Adjust L471, L472, and L473 for
minimum distortion.
32. Adjust VR470 for 140 mV of audio.
33. Set the signal generator output to I !-tv.
34. Adjust VR471 fully clockwise, then turn it
counterclockwise until the number 4 LED on
the front panel just comes on.
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