Pll Adjustmenst - Icom IC-FR4000 Service Manual

4-2 PLL ADJUSTMENT
ADJUSTMENT ADJUSTMENT CONDITIONS
1
TX VCO LOCK • LCD display
VOLTAGE • Receiving
1
RX VCO LOCK • LCD display
• Receiving
VOLTAGE
1
REFERENCE • Wait for 5 minutes after power ON.
FREQUENCY • LCD display
• Connect the RF power meter or 50 Ω
dummy load to the [TX] antenna con-
nector.
• Transmitting
2
• Push the [PROG] button.
• LCD display
• Receiving
1: [USA1], [GEN1], [GEN5], [EUR1]
2: [GEN2], [GEN6]
3: [USA3], [GEN3], [GEN7], [EUR3]
• TX UNIT TOP VIEW
CP1
: A01 LW TXREF 127
: A01 LW TXREF 127
: A01 LW TXREF
: A01 LW RXREF
4: [FRG1]
5: [FRG3]
CP1
TX VCO lock voltage
check point
C17
TX VCO lock voltage
adjustment
MEASUREMENT
UNIT LOCATION
TX
Connect the digital
multi meter or oscillo-
scope to check point
CP1.
RX
Connect the digital
multi meter or oscillo-
scope to check point
CP1.
REAR
Loosely couple the
panel
frequency counter to
the [TX] antenna con-
nector.
RX
Connect the frequen-
cy counter to check
point HJ4.
• TOP VIEW
• RX UNIT TOP VIEW
CP1 CP18
CP1
RX VCO lock
voltage chack point
4 - 5
ADJUSTMENT
VALUE
UNIT ADJUST
1 2 4
1.0 V , ,
TVCO
3 5
0.8 V ,
4.3 V
RVCO
1 3 4 5
, , ,
3.5 V
2
400.2750 MHz [PRT/BASE]
FRONT
1 4
,
430.2750 MHz
2
450.2750 MHz
3 5
,
359.2750 MHz [PRT/BASE]
FRONT
1 4
,
379.9250 MHz
2
409.9250 MHz
3 5
,
TX UNIT
RX UNIT
HJ4
Reference frequency
check point
C17
RX VCO lock voltage
adjustment
C17
C17
/[MONI]
/[MONI]