Rotel RT-961, 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

- Audio Frequency : 

1KHz

FM Signal Generator Setting 

- Deviation : 

75KHz

- Radio Frequency : 

98.1MHz

- Output Level : 

66dB

RT961  Setting 

- FM Frequency : 

97.9MHz

- FM MODE : 

MONO

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).

: THD shuold be within 0.5%

(B) Channel Separation adjust

RDS/STEREO Multiplexer Setting 

- MODE : 

STEREO ( ONLY L-CH Signal OUT )

- Audio Frequency : 

1KHz

FM Signal Generator Setting 

- Deviation : 

75KHz

- Radio Frequency :

 98.1MHz

- Output Level : 

66dB

RT961  Setting 

- FM Frequency : 

98.1MHz

- FM MODE : 

STEREO

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

- Audio Frequency : 

1KHz

FM Signal Generator Setting 

- Deviation : 

75KHz

- Radio Frequency :

 98.1MHz

- Output Level : 

26dB

RT961  Setting 

- FM Frequency : 

98.1MHz

- FM MODE : 

STEREO

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 RT-961'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)