Alignments

Cherokee AH-27 Alignment Procedure


Transmitter alignment

STEP SETTING CONNECTION ADJUST ADJUST FOR
1 RF Driver stage;
Mode: Transmit
Volume: N/A
Squelch: N/A
CH: 19
Connect oscilloscope
probe to base of
Q18
T9
T10
Adjust for
Maximum wave
form on the
oscilloscope.
2 RF Power Stage;
Mode: Transmit
Volume: N/A
Squelch: N/A
CH: 19
Connect dummy
load and RF power
meter to the external
ANT-Jack.
T11
RV-105
Adjust for Maximum
indication on the
Power meter, not to
exceed 4Watts
3 Second Harmonic check;
Mode: Transmit
Volume: N/A
Squelch: N/A
CH: 19
Connect RF Power
meter with dummy
load to spectrum
analyzer through
coupler -40dB atten.
to EXT ANT jack.
At no modulation,
compare the level
of fundimential
freq-spectrum to
the level of
harmonic freq-spectrum.
Suppression of the
2nd Harmonic must be
down at least 60 dB.
4 Frequency Check
Mode: Transmit
Volume: N/A
Squelch: N/A
CH: 19
Connect dummy
load and frequency
counter through
coupler to RF Power
meter. Also connect
power meter to
EXT-ANT jack.
CT-2 Make sure that the
indication of the
transmitter frequency
is 27.185 MHz +/- 300Hz
on the frequency counter.
5 Modulation check:
Mode: Transmit
Volume: N/A
Squelch: N/A
CH: 19
Connect dummy
load and modulation
meter through
coupler to RF Power
meter. Also connect
power meter to
EXT-ANT jack.
RV-4 Adjust for 90% +/- 5%
indication of modulation.


Receiver alignment

STEP SETTING CONNECTION ADJUST ADJUST FOR
1 RX Sensitivity;
Mode: Receive
Volume: Fully Clockwise
Squelch: Fully Counterclockwise
CH: 19
SSG: 28.185MHz, 1KHz Audio tone
1 uv(-107dBm), 30% AM modulation
Connect RF signal
gererator to external
ANT Jack. Connect
SSVM, Sinadder and
distortion meter
across EXT-SPeaker
output jack with 8 Ohm
load resistor
T1
T2
T4
T5






T6
Adjust the parts
of tuning circuitry
with observing ADM
"Automatic Distortion Meter"
indicates 10 dB S/N in AM
mode, and adjust output level
of RF-SSG until speaker
out level reaches about
500 milliwatt (2.0 Volts)

-adjust for Maximum
indicatiom ON╝SSVM
2 Squelch Adjustment:
Mode: Receive
Volume 500mW(2.0V)
Squelch: TIGHT
CH: 19
SSG: 28.185MHz,
1KHz Audio tone
2.815 uv(-38dBm),
30% AM modulation
Connect RF Signal
generator to external
ANT jack. Connect
RF Power meter and
distortion meter across
EXT-Speaker jack with
8 Ohm load resistor.
RV-1 Adjust the point until the
audio output appeared
on scope
3 Squelch Adjustment:
Mode: Receive
Volume 500mW(2.0V)
Squelch: Fully Counterclockwise
CH: 19
SSG: 28.185MHz,
1KHz Audio tone
100 uv (-67dBm),
NO╝MODULATION
Connect RF Signal
generator to external
ANT jack. Connect
RF Power meter and
distortion meter across
EXT-Speaker jack with
8 Ohm load resistor.
RV-2 Adjust so that the
9th LCD Bar display
on the LCD signal meter
has just been set.


This counter shows the number of hits since the 30th August 1998


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