Icom IC-751A Service Manual page 63

6-5 TRANSMITTER ADJUSTMENT
(1)
(2)
(6)
AC POWER SUPPLY
© Output voltage
© Current capacity
RF POWER METER (TERMINATED TYPE)
: 20 ~ 200W
: 1.8 ~ 30MHz
: 50Q
214
@ Measuring range
® Frequency range
e Impedance
° SWR
AF GENERATOR (AG)
© Frequency range
® Output level
AC MILLI-VOLTMETER
® Measuring range
RF VOLTMETER
® Frequency range
® Measuring range
OSCILLOSCOPE
© Frequency range
@ Measuring range
AMMETER
@ Measurement
capability to
FM DEVIATION METER
@ Frequency minimum
® Measuring range
® De-emphasis
: 13.8V DC
: 25A or more
: 200 ~ 3000Hz
: 0~ 300mV
: 10mV ~ 3V
0.1 ~ 80MHz
: 0.01 ~ 10V
>: DC ~ 20MHz
: 0.01 ~ 10V
: 1A and 25A
: 30MHz
: O~ +5kHz
: OFF
BIAS 1 | © Frequency display: 14MHz
VOLTAGE e SSB mode
@ For ® MIC GAIN CONTROL: Turn fully
driver tran- CCW
sistors © After confirming there is no MIC
input, set the transceiver in
transmit mode.
NOTE: Resolder after making
adjustments in steps 1 and
2.
For —*«2.|
final tran-
sistors
PA
AMMETER RF POWER
1A METER
—_——
W35, W10,
PA UNIT L_B20 OSCILLO-
SCOPE
AC POWER
SUPPLY
RF
VOLTMETER
AMMETER
22A
DEVIATION
METER
OSCILLO- *
SCOPE
Le ATTENUATOR
ANT more than
[| D13 40dB
J8(RF UNIT) (100W)
AF
GENERATOR
(AG)
MAIN UNIT
Desolder the center o
W35. Desolder
| IC-751A LS
AC MILLI-
VOLTMETER
W35
Connect an ammeter at
W35. re]
oO
p
oO
Q
\ | ammeter
fe LR-143
y Li7 i ie
"R27
Desolder R20 and
connect an ammeter
between W10 and R20.
Creo [GF
Desolder
O
'Lp
A }
600mA R23