Pll Adjustment - Icom IC-R3 Service Manual

5-2 PLL ADJUSTMENT

"TV RECEIVING SYSTEM", "REFERENCE FREQUENCY" AND "DETECTOR OUTPUT VOLTAGE" adjustments must be per-
formed at "ADJUSTMENT MODE".
ADJUSTMENT ADJUSTMENT CONDITION
1ST VCO
1 • Displayed frequency :
LOCK
VOLTAGE
• Receiving
(SHIFT ON)
(SHIFT OFF)
2 • Displayed frequency :
• Receiving
2ND VCO
1 • Displayed frequency :
LOCK
VOLTAGE • Receiving
CONVERTER
1 • Displayed frequency :
VCO LOCK
VOLTAGE
• Receiving
TV MODE
1 • Displayed frequency :
REFERENCE
FREQUENCY
• Mode
• Connect an SSG to the antenna
connector and set as:
Level
Modulation
• Receiving
TV
1 • Displayed TV receiving system
RECEIVING
adjustment menu (TV ch).
SYSTEM
REFERENCE
1 • Displayed frequency :
FREQUENCY
• Receiving
DETECTOR
1 • Displayed frequency :
OUTPUT
VOLTAGE
• Connect an SSG to the antenna
connector and set as:
Level
Modulation : OFF
• Receiving
*This output level of the standard signal generator (SSG) is indicated as SSG's open circuit.
799.995 MHz
0.495 MHz
0.495 MHz
1150.000 MHz
97.45 MHz
:TV
: 1 mV (60 dBµ)
*
: OFF
(FR ch) 1260.000 MHz
(TL ch) 30.100 MHz
: 1 mV (60 dBµ)
*
MEASUREMENT
UNIT LOCATION
VCO Connect the digital
multi-meter to the
check point CP1.
VCO Connect the digital
multi-meter to the
check point CP2.
VCO Connect the digital
multi-meter to the
check point CP3.
RF Connect the fre-
quency counter to
the check point
CP6.
DISPLAY
RF Connect the fre-
quency counter to
the check point
CP5.
RF Connect the digital
multi-meter to the
check point CP1.
5 - 3
ADJUSTMENT
POINT
VALUE
UNIT
14.5 V VCO
2.5 V
3.2 V – 5.2 V VCO
0.8 V VCO
2.5 V RF
4.5 Top
panel
1320.0000 MHz Top
panel
1.0 V RF
ADJUST
L64
L63
Verify
L919
L902
[DIAL]
[DIAL]
L21