Pa Unit Adjustment - Yaesu FT-891 Technical Supplement

PA Unit Adjustment

Preparation
 Connect the Microphone to the Microphone
jack.
 C o n n e c t t h e 5 0 - O h m D u m m y L o a d a n d
Wattmeter to the ANT jack.
 Disconnect the cable from J5001 on the PA Unit,
then terminate J5001 with a 50-Ohm resistor.
 Disconnect the jumper plug from J5003.
 Connect the DC ammeter to J5003.
 Press and hold the PTT switch, while adjust
VR5001 so the DC ammeter reading is "55 mA
(±5 mA)".
 Release the PTT switch.
 Disconnect the DC ammeter from J5003.
 Disconnect the jumper plugs from J5005.
 Connect the DC ammeter to J5005.
 Press and hold the PTT switch, while adjust
VR5002 so the DC ammeter reading is "1.0 A
(±0.1 A)".
VR5004
VR5002
VR5003
J5005
VR5001
J5001
J5003
 Release the PTT switch.
 Disconnect the DC ammeter from J5005.
 Connect the DC ammeter to the Power Supply.
 Turn both VR5003 and VR5004 fully counter-
clockwise.
 Press and hold the PTT switch, while adjust
VR5003 so that the DC ammeter "1.0 A (±0.1 A)"
increase.
 Adjust VR5004 so that the DC ammeter "1.0 A
(±0.1 A)" increase.
 Release the PTT switch.
 Re-connect the jumper plugs to J5003 and J5005.
 Disconnect the DC ammeter from the Power
Supply.
 Disconnect the 50-Ohm resistors from J5001,
then connect the cable to J5001.
ALIGNMENT-11
Alignment
FT-891 Technical Supplement