Galaxy DX 979, Service Manual

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4.1.2 TRANSMITTER ALIGNMENT
ITEM U.U.T. SETTING
ADJUST
POINT
MEASUREMENT
BIAS Current Set radio to CH 19 USB TX mode.
Modulation Off.
Remove “short PCB” from TP7, TP8, TP9.
Connect current meter to TP7(+) and TP9 (-)
Connect current meter to TP7(+) and TP8 (-)
VR12
VR10
50 mA
100 mA
SSB APC Set radio to CH 19 USB RX mode.
Connect Multi-meter to TP7. VR17 12.5 VDC
SSB TX Power Connect “short PCB” to TP7 and TP9.
Connect RF Power Meter to antenna jack.
Set radio to CH 19 USB TX mode.
AF signal 30mV, 1 KHz to microphone.
Set RF PWR fully clockwise.
Set MIC GAIN fully clockwise.
L40,L42,
L43,L44 MAX > 12W
Spurious Emission
Minimum.
Balance Power
Between CH1 and
CH40.
SSB ALC
Set radio to CH 19 USB TX mode.
AF signal 30mV, 1 KHz to microphone.
VR13
11.5 W
SSB Carrier
Balance Set radio to CH 19 USB TX mode.
Set MIC GAIN fully counter-clockwise.
Connect Oscilloscope to antenna connector.
VR6
Spurious Emission to
Minimum.
AM TX
High Power Set radio to CH 19 AM TX mode.
Modulation Off.
Set RF POWER fully clockwise.
VR14
3.8 W
AM TX
Low Power Set RF POWER fully counterclockwise.
VR18
0.3W
±
0.2W
RF Power
Meter Set radio to CH 19 AM TX mode.
Set RF POWER fully clockwise.
Set SWR/MOD/PWR Switch to PWR
position.
VR9 For a needle reading
of “4” on TX PWR
scale.
AM Modulation
Set radio to CH 19 AM TX mode.
AF signal 30mV, 1 KHz to microphone.
Set MIC Gain fully clockwise.
Set SWR/MOD/PWR Switch to MOD position
VR16
For a needle reading
of 95% on the
external modulation
meter.
AM Modulation
Meter Set radio to CH 19 AM TX mode.
AF signal 30mV, 1 KHz to microphone.
Set MIC Gain fully clockwise. VR15 For a needle reading
of 95% on the
modulation scale.