Yaesu FT-450, Техническое дополнение, Страница: 12 / 69

ALIGNMENT-4
Alignment
PA Unit
Preparation
Connect the 50-Ohm Dummy Load and Wattme-
ter to the "ANT" jack.
Cut the lead of L5008 on the PA Unit.
Set VR5401, VR5402, VR5403, and VR5404 on the
PA Unit to fully counter clockwise position.
Set the transceiver to 14.150 MHz in the USB
mode.
Pre-Drive Stage Idling Current
Disconnect the jumper plug from J5003 on the
PA Unit, and then connect the DC ammeter to
J5003.
Press the PTT button; adjust VR5401 on the PA
Unit so the DC ammeter reading is 100 mA ± 10
mA.
Release the PTT button.
Drive Stage Idling Current
Disconnect the jumper plug from J5004 on the
PA Unit, and then connect the DC ammeter to
J5004.
Press the PTT button; adjust VR5402 on the PA
Unit so that the DC ammeter reading is 0.5 A ± 50
mA.
Release the PTT button.
Press the PTT button; adjust VR5403 on the PA
Unit so the DC ammeter reading is 1.0 A ± 50 mA.
Release the PTT button.
Final Stage Idling Current
Connect the DC ammeter to the lead of L5008.
Press the PTT button; adjust VR5404 on the PA
Unit so the DC ammeter reading is 1.0 A ± 100
mA.
Release the PTT button.
Press the PTT button; adjust VR5405 on the PA
Unit so the DC ammeter reading is 2.0 A ± 100
mA.
Release the PTT button.
Concluding
Re-connect the jumper plugs to J5003 and J5004,
and then solder the lead of L5008.
CM Coupler Balance
Connect the DC voltmeter between TP5430 (+
lead) on the PA Unit and Chassis (- lead).
Set the transceiver to 29.200 MHz in the CW
mode.
Press the PTT switch; adjust TC5400 on the PA
Unit for minimum deflection on the DC voltme-
ter (less than 0.1 V).
Release the PTT switch.