Adjustment - Rotel RSX-972 Technical Manual

Tuner Adjustment Method
FM Section
* Necessary measurement equipment
RDS/STEREO Multiplexer, FM/AM Signal Generator, Audio Analyzer, Oscilloscope, Digital Volt Meter (DVM)
(A) Center adjust
RDS/STEREO Multiplexer Setting
- MODE : MONO
FM Signal Generator Setting
- Deviation : 75KHz
RSX972 Setting
- FM Frequency : 97.9MHz
1. Turn FM Signal Generator Modulation on
2. Connect DVM (+)(-) terminals to Jumper J7 and J8 and measure the volt.
3. If measured voltage is not adjusted within ±10mV, Make this measured volt '0' by adjusting T04 (FM-DET-A Coil).
: The adjustment should be within ± 10mV
4. After this adjustment, measure THD(Total Harmonic Distortion) with Audio Signal Generator
5. Adjust THD to minimum point with T05(FM-DET-B Coil).
(B) Channel Separation adjust
RDS/STEREO Multiplexer Setting
- MODE : STEREO ( ONLY L-CH Signal OUT )
FM Signal Generator Setting
- Deviation : 75KHz
RSX972 Setting
- FM Frequency : 98.1MHz
1. Turn FM Signal Generator Modulation on after modulating only L-CH (or only R-CH) at STEREO Multiplexer.
2. Confirm if 'STEREO'indicator is turned 'ON' on the display
3. Measure output level via Audio Signal Analyzer and make the level as standard.
4. Turn FM Signal Generator Modulation on after modulating only R-CH (or only L-CH) at STEREO Multiplexer.
5. Measure output level via Audio Signal Analyzer (measure per a dB)
6. If meaured output level is not lower than -40dB, Adjust output level to minimum position with VR03 ( CH-SEPA. ADJ.).
: lower than -40dB
(C) TUNED Level adjust
RDS/STEREO Multiplexer Setting
- MODE : STEREO
FM Signal Generator Setting
- Deviation : 75KHz
RSX972 Setting
- FM Frequency : 98.1MHz
1. Turn FM Signal Generator Modulation 'ON' (confirm if output level is 26dB)
2. Change the output level of the Generator from 20dB to 30dB
and Confirm if 'STEREO' & 'TUNED' indicator of the DISPLAY turns on at 26db(±5 dB)
3. If these indicators do not turn on at higher than 26dB(±5dB) or do not turn off at lower than 26(±5dB) ,
Adjust VR02 ( FM-ADJ ) up to the moment where 'STEREO' & 'TUNED' indicator turns OFF & ON at 26dB.
4. Confirm if 'STEREO' & 'TUNED' turns OFF when decreasing the output level slowly from 26dB to 25dB, 24dB ~~~.
(Repeat the above 3. if not OFF in lower than 24dB.)
5. Push RSX-972's TUNE UP or DOWN button "long" at Signal Generator Output Level 26dB and start Auto search.
Confirm if search stops at FM Frequency 98.1MHz.
(Examine both of High Freq. -> 98.1MHz search , Low Freq. -> 98.1MHz search)
- Audio Frequency : 1KHz
- Radio Frequency : 98.1MHz
- FM MODE : MONO
- Radio Frequency : 98.1MHz
- FM MODE : STEREO
- Audio Frequency : 1KHz
- Radio Frequency : 98.1MHz
- FM MODE : STEREO
16
- Output Level : 66dB
: THD shuold be within 0.5%
- Audio Frequency : 1KHz
- Output Level : 66dB
- Output Level : 26dB