NAD 712 - Alignment and Calibration Procedures; FM Section Alignment Procedures; IF and Synthesizer Alignment; RF, Auto-Search, and Stereo Alignment

ALIGNMENT PROCEDURES
FM. SECTION
AF MODULATION: 1 kHz, 75 kHz DEVIATION, MONO MODE
STORE FREQUENCY: 98 MHz, 87.5 MHz, 108 MHz, 90 MHz, 106 MHz
RF LEVEL: 75-ohm IMPEDANCE, OPEN CIRCUIT
OSCILLATION TUNING VOLTAGE
Connect DVM between TP701 & GND.
For A16 Froni-end Module:
Tune to 87.5 MHz, adjust FE4 (osc coil) to read 3 +
Tune to 108 MHz, adjust FE4 (osc coil) to read 20.5
For G55 or G58 Front-end Module:
Tune to 87.5 MHz, adjust FE4 (osc coil) to read 1.6 + 0.5 V.
Tune to 108 MHz, adjust FE4 (osc coil) to read 8.0 + 0.5 V.
0.5 V.
+0.5V.
LF.
Connect DVM between TP703 & TP704
Apply 10.7 MHz, 90 dBp via 1K-ohm to TP702.
Adjust L706 to read 0 + 50 mV.
Adjust L707 for minimum distortion (THD).
Repeat adjustment until no further improvement.
SYNTHESIZER I.F. TRACKING
Disconnect 10.7MHz tap to TP702.
Maintain connection of DVM across TP703 & TP704.
Apply 98 MHz, 60 dBy to antenna input.
Tune to 98 MHz.
Adjust C701 to read 0 + 20 mV.
Fine adjust L707 for minimum distortion.
Repeat until no further improvement.
FRONT-END IF
Connect DVM between TP705 and ground.
Turn RR742 fully clockwise and R736 fully anti-clockwise.
Apply 98 MHz, 18 dBy to antenna input.
Adjust FES to obtain minimum reading on DVM.
R.F.
Apply 98 MHz, 8 dBu for AH or 22 dBy for C, to antenna input.
Check THD.
If THD > 3%, adjust FE1, FE2 & FES in the front-end module with non-metallic tool for minimum THD.
Check THD at.90 MHz & 106 MHz with 9 dBu input for AH, or 23 dBy for C.
AUTO-SEARCH LEVEL
Turn R736 fully clockwise and RR742 fully anti-clockwise.
Set stereo modulator to L = R mode.
Apply 98 MHz, 18 dBy to antenna input.
Adjust R736 until Center Tune LED just light.
Increase input level to 22 dBu.
Adjust RR742 until FM stereo LED just light.
Check if auto-seach works at 28 dBu.
FM Stereo: 1kHz, 67.5kHz devi., 60dBuV, Pilot signal 19kHz, 7.5kHz devi.
STEREO SEPARATION & PILOT SUPPRESSION
Set modulated signal to Left only.
Adjust R753 for minimum output at Right channel.
Set modulated signal to Right only.
Adjust R753 for minimum output at Left channel.
Repeat until readings are the same.
Turn off modulating signal, leaving the pilot tone.
Adjust FL704 and FL705 for minimum outputs on Right and Left channels respectively.
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