Yaesu FT-857 series, Техническое дополнение

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13
Local Oscillator Adjustment
Reference Frequency Adjustment
1. Connect an RF millivoltmeter or an oscilloscope to
pin 2 of J5002 on the REF Unit.
2. Confirm that the RF millivoltmeter reading is 115 mV
(± 30 mV) rms or 320 mV (± 90mV) p-p.
3. Connect the frequency counter to pin 2 of
J5002
on
the REF Unit.
4. Adjust the
TC5001
for 67.875000 MHz (±10 Hz) on
the frequency counter.
3rd Local Adjustment
1. Connect an RF millivoltmeter or an oscilloscope to
TP1037 on the MAIN Unit.
2. Key the transceiver on CW mode, and adjust
T1025
for maximum indication on the RF millivoltmeter.
3. Confirm that the indicated voltage is 100 mV (± 30
mV) rms or 280 mV (± 80mV) p-p.
PLL Adjustment
VCO VCV Adjustment
1. Connect the DC voltmeter to
TP1028
on the MAIN
Unit (or pin 6 of J2002 on the PLL Unit), and refer-
ring to the table below, tune the transformer/inductor
on the PLL Unit on each frequency listed. Then con-
firm that the correct voltage is present, or adjust the
listed component for the required voltage.
Tune to : Adjust / Confirm For
13.895 MHz Adjust T2001 5.5V ±0.5V
76.000 MHz Confirm At least 0.8V
32.995 MHz Adjust T2002 5.5V ±0.5V
19.900 MHz Confirm At least 0.8V
55.995 MHz Adjust T2003 5.5V ±0.5V
88.000 MHz Confirm At least 0.5V
163.995 MHz Adjust L2010 5.5V ±0.5V
118.000 MHz Confirm At least 0.5V
469.995 MHz Adjust L2011 5.5V ±0.5V
420.000 MHz Confirm At least 0.5V
1st Local Output Level
1. Connect the RF millivoltmeter to
TP1029
on the
MAIN Unit (or pin 11 of J2002 on the PLL Unit), and
set the transceiver to 28.000 MHz.
2. Confirm that the RF level is at least 0 dBm or 200 mV
rms.
Alignment
MAIN Unit Alignment Points I
REF Unit Alignment Points
TP1037
T1025
TP1028
TP1029
TC5001 J5002
(
pin 2
)