Tuner Adjustment Table; Tuner Board - Philips MX2600/77 Service Manual

6-1

TUNER BOARD

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TUNER ADJUSTMENT TABLE

Waverange Input frequency
VARICAP ALIGNMENT
FM
87.5 - 108MHz
(50kHz grid)
AM
530-1710kHz
(10kHz grid)
( 21L / 21L / 37S )
FM - IF
FM
continuous wave
FM - RF
FM
AM IF
AM
Connect pin 29 of
IC001 (AM Osc.)
with short wire to
AM AFC
ground (pin 6)
MW
3)
AM RF
MW
Use Service Testprogram. By selecting the TUNER TEST test frequencies will be stored as preset frequencies automatically.
1)
If sensitivity of frequency counter is too low adjust to max. channel separation
(input signal: stereo left 90% + 9%, adjust output on right channel to minimum)
3) For AM RF adjustments the original frame antenna has to be used!
6-1
Input Tuned to Adjust
108MHz
check
87.5MHz check
1602KHz check
T005
531KHz
check
1700KHz
T005
530KHz
IC001
23
10.7MHz, 50mV
No need
short circuit
200P
to adjust
to block AFC
106MHz VC001
108MHz
L001
87.5MHz mod=1kHz 90.1MHz
∆f= ±22.5kHz
IC001 T001
24
450kHz 100nF
T002
∆f = ±15kHz
V = 3mV
RF
T003
∆ V=mV
1404kHz 1404kHz VC001
576kHz 612kHz T006
∆f = ±30kHz
1400kHz 1400kHz VC002
V as low as
RF
possible
610kHz
610kHz T006
2)
RC network serves for damping the IF-filter while
adjusting the other one.
Output Scope/Voltmeter
6.5V ±1.2V
1.0V ±0.5V
7.8V ± 0.2V
±
1.1V 0.5V
8.0V ± 1HV
1.1V ± 0.2V
fo
Symmetric
MAX
MAX
MAX
f
o
symmetric
MAX
f
o
symmetric