Icom IC-725 Instruction Manual page 29

8 MAINTENANCE AND ADJUSTMENT
8-7 ADJUSTMENTS All adjustable trimmers and coils should be adjusted by an
the factory before being shipped. internal adjustments.
e ADJUSTMENT POSITION
1) The brake adjustment screw is located on the left
side of the MAIN DIAL.
2) Turn the brake adjustment screw clockwise-or coun-
terclockwise to a comfortable tension level while
turning the MAIN DIAL continuously and evenly in
one direction.
(2) PA UNIT IDLING CURRENT The PA unit operates with a linear amplifier and requires
some idling current to flow through the driver and final
transistors to obtain bias voltage.
ФРА UNIT Я
1) Preparation:
[POWER] switch > OFF
[MIC] control > Max. counterclockwise
[RF PWR] control ^ Max. counterclockwise
Microphone > Disconnect
Ammeter -» 100 mA range for driver
transistors
500 mA range for final transistors
2) Unsolder points indicated by *1 and *2.
3) Properly connect test leads to points. See diagrams
for the driver and final amp. adjustments.
4) Turn transceiver power ON.
5) Push the [SSB] switch to select LSB or USB mode.
6) Push the [TRANSMIT] switch IN to transmit.
7) Adjust R8 to set 50 mA for the driver amp.
Adjust R19 to set 300 mA for the final amp.
8) Turn transceiver power OFF.
9) Re-solder the de-soldered points.
C28, EP21