Tx Output Power Check And Adjustment - Furuno FS-1575 Service Manual

4. TX output Power Check and Adjustment

4.1 Power Check and Adjustment (See 5-11 to 5-14)
Power check in SSB mode:
Select [MENU] -> 1.TEST -> 3.TONE TEST (by 1-tone or 2-tone signal)
Power adjustment:
Select [MENU] -> 9.SERVICE -> 3.RT SETUP -> 4.TX PWR (FREQ), 5.TX PWR
(USER CH), 6.TX PWR (TUNE) or 7.TX PWR (SEL CALL).
4.2 ALC Adjustment (See 5-48)
Power adjustment is made with power data. However, when the TX FIL, TX, PA, and/or
DRV boards are replaced, power may vary on all bands.
In this case, make power adjustment with [R43: ALC VR] on the TX FIL board. This
allows for making power adjustment on all bands at a time.
1) Connect the Power meter (50 ohms) to the output port of the T/R ANT.
2) Set the band to SSB 12M band.
3) Select [MENU] -> 1.TEST -> 3.TONE TEST -> 1100/1700Hz (2-tone).
4) Transmit frequency to make power adjustment with [R43: ALC VR] on the TX
FIL board so that it will come to the rated TX output power.
FS-1575:
FS-2575:
FS-5075:
5) Check for power on other bands. If necessary, make power adjustment according
to power data.
4.3 Measures against High Reflected Power
If reflected power is 20% or more of the rated TX output power, check the antenna
centering on the following:
Damage to the antenna
Touch of the antenna including its lead-in wire with structure
Proper grounding of the ATU
Internal burnout of the antenna coupler
Soldering of coaxial connector of the antenna and its connection to the ATU
Water leakage from the coaxial cable of the antenna
If no problems, it is advisable to reduce power by 10% to 20%.
CONFIDENTIAL (internal use only)
This confidential document is used only by FURUNO authorized persons.
It is strictly prohibited to reproduce the document in whole or in part without prior written permission of FURUNO.
75W (150W x 1/2),
125W (250W x 1/2),
250W (500W x 1/2)
5
Summary