Software Adjustments - Icom IC-R20 Service Manual

5-2 SOFTWARE ADJUSTMENTS

ADJUSTMENT
REFERENCE 1 • Connect the frequency counter to the check point
FREQUENCY CP18 on the RF unit.
[REF] • Receiving
1 • Dual watch mode
CENTER
VOLTAGE • Set the receiver to [A-BAND] and FM mode.
• Operating frequency
• Connect an SSG to the antenna connector and set as
Level
Frequency
Modulation
• Connect the Digital multimeter to the check point CP1
on the RF unit.
• Receiving
2 • Set the receiver to [B-BAND] and FM mode.
• Operating frequency
• Connect an SSG to the antenna connector and set as
Level
Frequency
Modulation
• Connect the Digital multimeter to the check point CP11
on the RF unit.
• Receiving
1 • Connect the frequency counter to the check point on
BFO
[LSB] the LOGIC unit (See page 5-3).
• Receiving
[USB] 2 • Connect the frequency counter to the check point on
the LOGIC unit (See page 5-3).
• Receiving
[CW] 3 • Connect the frequency counter to the check point on
the LOGIC unit (See page 5-3).
• Receiving
SSB-IF 1 • Connect an SSG to the antenna connector and set as
SHIFT Frequency
[LSB-IFS] Modulation
• Receiving
2 • Set an SSG as
Level
Frequency
Modulation
• Receiving
3
[USB-IFS] • Connect an SSG to the antenna connector and set as
Frequency
Modulation
• Receiving
4 • Set an SSG as
Level
Frequency
Modulation
• Receiving
*This output level of a standard signal generator (SSG) is indicated as SSG's open circuit.
ADJUSTMENT CONDITION
: ON
: 145.100 MHz
: 1 mV* (–47 dBm)
: 145.100 MHz
: OFF
: 145.100 MHz
: 1 mV* (–47 dBm)
: 145.100 MHz
: OFF
: 14.0990 MHz
: OFF
: A+ 35 dB
: 14.1005 MHz
: OFF
: 14.1010 MHz
: OFF
: A+ 35 dB
: 14.0995 MHz
: OFF
• Rotate [R-DIAL] to set to 247.05000 MHz.
• Push [• LOCK] key.
• Adjust L21 to CP1 voltage to be 1.0 V.
• Adjust L105 to CP11 voltage to be 1.0 V.
• Rotate [R-DIAL] to set to 448.5 kHz.
• Push [• LOCK] key.
• Rotate [R-DIAL] to set to 451.5 kHz.
• Push [• LOCK] key.
• Rotate [R-DIAL] to set to 449.2 kHz.
• Push [• LOCK] key.
• Set an SSG's level to 10 dB S/N sensitivity (A).
• Measure the AF output level while the IC-R20
outputs 1 kHz signal (B).
• Measure the AF output level (C).
• If AF output level C is lower than B, skip this
adjustment.
• If AF output level C is higher than B, rotate
[R-DIAL] to adjust the AF output level to the same
level as B.
• Push [• LOCK] key.
• Set an SSG's level to 10 dB S/N sensitivity (A).
• Measure the AF output level while the IC-R20
outputs 1 kHz signal (B).
• Measure the AF output level (C).
• If AF output level C is lower than B, skip this
adjustment.
• If AF output level C is higher than B, rotate
[R-DIAL] to adjust the AF output level to the same
level as B.
• Push [• LOCK] key.
5 - 2
OPERATION