Alinco DR-570T/E, Service Manual

Page: 15 / 51

■ ADJUSTMENT (VHF)
Item
A d ju stm ent
p oint(s)
A dju stm ent m ethod
VCO Voltage [D]TC1
TC2
(VCO BOX)
At 445.000 MHz (T) or 435.000 MHz (E), adjust TC1 so that the voltage
of TP3 on [
b
] substrate is 1.8 V.
At 445.000 MHz (T) or 435.000 MHz (E), pressing the PTT button,
adjust TC2 so that the voltage of TP3 on [¥] substrate is 3.8 V.
G E M
(VCO BOX)
At 145.000 MHz, adjust TP2 so that the voltage of TP2 on
[
a
]
substrate
is 4.0 V.
Basic Frequency
[
a
]TC1
Pressing PTT button, adjust TC1 so that f-counter indicates
444.950 ±0.1 kHz (T) or 434.950 ±0.1 kHz (E) MHz.
TX Power
[o] VR2
VR3
On “LO” position, pressing the PTT button, adjust VR2 and VR3 so that
the power is maximum at 145.95 MHz (T) or 144.95 MHz (E).
Power Output [O] VR2 (Hi) On “Hi” position, turn VR2 for 46 W output at 145.95 MHz (T) or
144.95 MHz (E).
Verify the lighting of the entire RF meter.
[o]VR4 (Lo) On “Lo” position, turn VR4 for 5 W output at 145.95 MHz (T) or
144.95 MHz (E).
RF meter
[0] VR1 On “Lo” position, adjust VR1, so that [
5
] on the RF metter lights up at
145.95 MHz (T) or 144.95(E).
Deviation ® V R 3 Enter the AF level of OdBm, then pressing the PTT button, adjust VR3
so that you obtain 4.6 kHz/Dev at 145.95 MHz (T) or 1449.95 MHz (E)
and AF 1 KHz.
Protection Circuit
[o] VR3 Disconnect the antenna, then pressing the PTT button and adjust VR3
so that the current consumption is 4.5 A at 145.95 MHz (T) or
144.95 MHz(E).
Subaudible Tone
Deviation
(DR-570T) Pressing the tone button and the PTT button at 145.95 MHz, verify
0.5—1 kHz/Dev at tone frequency of 88.5 Hz.
1750 Hz Tone
Deviation
(DR-570E)
Connect Microphone (EHM-34A or 33A), then pressing the tone button,
verify that the tone frequency is 1750 Hz and the deviation is 3.5 kHz
±0.5 kHz.
Discrimination 0 L7, 8, 9 At 146.03 MHz (T) or 145.03 (E) and 60 dBn input, adjust L7, 8, 9, so
that the distortion is minimum at 50 m W.
Sensitivity
0 L2, 3, 4, 5, 6 Adjust L2, 3,4, 5, 6 so that 12 dB SINAD sensitivity is the highest at
146.03 MHz (T) or 145.03 MHz (E).
Squelch Sensitivity 0 V R 1 At 146.03 MHz (T) or 145.03 MHz (E), turn the main squelch knob to the
minimum and cut SG output, then adjust VR1 so that the noise is
maximum.
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