Adjustment (Vhf) - Alinco DR-570T/E Service Manual

■ ADJUSTMENT (VHF)

Item
VCO Voltage [D]TC1
(VCO BOX)
E L 4
Basic Frequency 0 T C 1
TX Power
[0] VR2
Power Output
\ \
0
RF meter
[o] VR1
Deviation
[ ]
a
Protection Circuit [0] VR3
Subaudible Tone
Deviation
(DR-570T)
1750 Hz Tone
Deviation
(DR-570E)
Discrimination
0 L7, 8, 9
Sensitivity
Squelch Sensitivity
0 V R 1
Adjustment
point(s)
At 445.000 MHz (T) or 435.000 MHz (E), adjust TC1 so that the voltage
TC2 of TP3 on
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.
At 145.000 MHz, adjust TP2 so that the voltage of TP2 on
(VCO BOX) is 4.0 V.
Pressing PTT button, adjust TC1 so that f-counter indicates
444.950 ±0.1 kHz (T) or 434.950 ±0.1 kHz (E) MHz.
On "LO" position, pressing the PTT button, adjust VR2 and VR3 so that
VR3 the power is maximum at 145.95 MHz (T) or 144.95 MHz (E).
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.
VR4 (Lo) On "Lo" position, turn VR4 for 5 W output at 145.95 MHz (T) or
144.95 MHz (E).
On "Lo" position, adjust VR1, so that [sjon the RF metter lights up at
145.95 MHz (T) or 144.95(E).
VR3 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.
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).
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.
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.
At 146.03 MHz (T) or 145.03 (E) and 60 dBp input, adjust L7,8, 9, so
that the distortion is minimum at 50 m W.
L2, 3, 4, 5, 6
Adjust L2, 3,4, 5, 6 so that 12 dB SI NAD sensitivity is the highest at
146.03 MHz (T) or 145.03 MHz (E).
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.
Adjustment method
substrate is 1.8 V.
[ ]
b
1 5
- -
substrate
[ ]
a