Adjustments - Pioneer F-91 Service Manual

F-91
7.
ADJUSTMENTS
AM Section Adjustments
• Wire as shown in Fig.
7
-
I
• Set the AM key to ON and the REC LEVEL CHECK key to OFF.
Step
_
AM SG
(400Hz, 30% de modulation)
F-91
frequency
indication
Adjustment
point
Adjustments
Standard
Frecuency Level
1
No signal
530kHz
1531kHz1 •1
L301
Adjust so that the voltage between terminal 33 and ground
is 2V (± 0.3V).
2 1,700kHz
(1,602kHz)"
TC301
Adjust so that the voltage between terminal 33 and ground
is 24.5V 1±0.5V1.
3
Repeat steps 1 and 2 until both ground voltage standards are satisfied.
4 Mechanically set VR301 to the midpoint.
5 600kHz
(603kHz)•1
50 — 80dB
600kHz
(603kHzr 1
T301
Maximize the voltage between terminal 35 and ground.
6 1,400kHz
(1,395kHz
)
"
50 — 80dB
1,400kHz
(1,395kHz1 •1
TC302
7
Repeat steps 5 and 6 until the maximum voltage standard is satisfied in both steps.
B
600kHz
(603kHz1 •1
100dB
600kHz
1603kHzr 1
VR301
Adjust so that the voltage between terminal 35 and ground
is 4.9V (±0.1V). •2
'1: The frequency in the parenthesis is the frequency at 9kHz STEP (HE and HB types').
*2: Do not let the voltage of terminal 35 exceed 5.2V.
FM Section Adjustment
Note: The adjustment method of this FM section is simple throughout.
• Wire as shown in Fig.
7
-
2
• Set the FM key to ON, and the EEC LEVEL CHECK and MUTING keys to OFF.
Stec)
FM SG
(1kHz, ±75kHz deviation)
F-91
frequency
indication
Adjustment
point
Adjustments
Standard
Frequency Level
1
No signal
108MHz L3
Adjust so that the voltage between terminal 33 and ground
is 23.5V ( ± 0.2V).
87.5MHz
Confirm that the voltage between terminal 33 and ground
is 7,5V (± 1,0V).
90MHz 40dB 90MHz
L1, T1, L2
Maximize the voltage between terminal 22 and ground.
4
106MHz 40d13
106MHz TC1—.3
5 Repeat steps 3 and 4 until both ground voltage standards are satisfied. Terminate the adjustment with step 4.
6 106MHz 60dB
106MHz T103—a
Sat the voltage to OV for terminal 24 to 26.
98MHz
18dB
(Stereo
modulation)*
98MHz VR103
Adjust to the point just before muting is applied.
98MHz 40dB 98MHz —
Check the output level of the output terminal.
Set the REC LEVEL CHECK key to ON.
VR302 At step 8, set the output level of the output terminal to
—6d8 (± 1dB).
• Stereo modulation: Main 1kHz, L-R, ± 68.25kHz dev. pilot 19kHz, ± 6.75kHz dev.