Icom IC-7800 Service Manual Addendum page 379

RXPLL-A UNIT ADJUSTMENTS–Continued
ADJUSTMENT ADJUSTMENT CONDITION
HPL LOCK 12 • MAIN display frequency
VOLTAGE
• Mode
(VCO6)
• Receiving
1 • MAIN display frequency
R1 LO
OUTPUT
• Mode
• Receiving
2LO LOCK 1 • MAIN display frequency
VOLTAGE
• Mode
• Receiving
1 • MAIN display frequency
R2 LO
OUTPUT
• Mode
• Receiving
T2 LO 1 • MAIN display frequency
OUTPUT
• Mode
• Receiving
1 Pre-set the IC-7800 as the following
RX
SENSITIVITY condition.
• MAIN display frequency
(HF)
• Mode
• Dualwatch
• MAIN Ant.
• Pre-amp. 1
• SUB AF
• Receiving
2
• MAIN display frequency
• Mode
• Connect an SSG to [ANT1] connec-
tor and set as;
Frequency : 14.1515 MHz
Level
Modulation : OFF
• Receiving
*This output level of a standard signal generator (SSG) is indicated as SSG's open circuit.
UNIT
RX
: 45.000 MHz PLL-A
: USB
RX
: 14.999 MHz PLL-A
: USB
RX
: 14.100 MHz PLL-A
: USB
RX
: 14.100 MHz PLL-A
: USB
RX
: 14.100 MHz PLL-A
: USB
RX
PLL-A
: 14.150 MHz
: USB
: OFF
: ANT1
: ON
: Minimum level
Rear
panel
: 14.150 MHz
: USB
: 1 µV* (–107 dBm)
MEASUREMENT
LOCATION
Connect a DC volt-
meter to CP2 (LV2).
Connect an RF volt-
meter to J351 (R1LO).
Connect a DC volt-
meter to CP3.
Connect a spectrum
analyzer to J831
(R2LO).
Connect a spectrum
analyzer to J561
(T2LO).
Connect a DC volt-
meter to CP1102.
Connect a DC volt-
meter to CP1103.
Per-set L1401, L1402,
L1403, L1404, L1405
and L1406 as the illus-
tration at right.
Connect an AC milli- Maximum audio level
volt meter to [EXT SP]
jack with 8 Ω load.
4 - 6
ADJUSTMENT
POINT
VALUE
UNIT
1.2 V–2.0 V RX
PLL-A
2.25 dBm ±0.25 dB RX
PLL-A
3.0 V ±0.3 V RX
PLL-A
Maximum level RX
(–10 dBm ±3.0 dB) PLL-A
Maximum level RX
(3.0 dBm ±3.0 dB) PLL-A
4.5 V ±0.1 V RX
PLL-A
4.5 V ±0.1 V RX
PLL-A
Center RX
position PLL-A
RX
2 rotations
PLL-A
Core
RX
3.5 rotations
PLL-A
Core
RX
Core's top
PLL-A
RX
PLL-A
ADJUST
Verify
R357
C546
L801,
L834
Adjust
repeatedly
L565,
L566
R1101
R1132
R1228
L1401,
L1402
L1403,
L1404
L1410,
L1411
L1408,
L1058