Summary; Introduction - Furuno FS-1575 Service Manual

Introduction

For equipment checks, start with checks for antenna, antenna coupler, and antenna
lead-in wire. For example, check the antenna coupler for any burnout and the antenna
lead-in wire for proper connection and contact with stanchion.
1) To check for RX, check for receiver sensitivity by band.
If no communication is in progress, approximate sensitivity can be roughly checked
by connecting and disconnecting the reception antenna or hearing changes in noises.
The main point is to check based on the band divisions of the RX FIL board. For
details, refer to information on page 7-37.
2) To check for TX, make measurement of SWR on all bands using a power meter. If
Pr on a specific band exceeds 20% of the rated TX output power, it is advisable to
reduce the TX output power on the relevant band within the standard range.
In this case, it is required that the Transceiver unit including the antenna, antenna
coupler, and TX FIL board has no problem.
If no power meter is available, approximate TX output power can be found from PA
IC and PA VC values. Refer to the table shown below. It shows data on
measurement made with a single tone.
Furthermore, check for all detection voltage referring to the TX output power of the
DRV, PA, and TX FIL circuits and detection voltage characteristics data described
in "6.11 Level Check" on page
FS-5075
(500W)
FS-2575
(250W)
FS-1575
(150W)
3) Ensure that self-tests and self-checks all resulted in "OK."
If "NG," this basically resulted from failures of the relevant board. Even if
transmission tests resulted in "OK" with all the PA, DRV, and TX FIL boards,
make an overall judgment based on TX output power (Pf/Pr), numerical results of
the tests, and PA IC and PA VC values.
For example of self-check results, refer to information in "6.2 SERVICE: SELF
CHECK" on page 6-15.
4) For a service report, describe by band not only symptoms, causes, and measures,
but also measurements of TX output power (Pf/Pr), and PA IC, PA VC, Ia and VS
values. Furthermore, describe antenna type, length, and lead-in length without fail.
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.
6-74. This shows approximate TX output power.
PA VC PA IC
42V 18 to 25A
42V 9 to 14A
24V
1
24V Input
Efficiency
Current
60 to 45% 45 to 55A
60 to 45% 25 to 30A

Summary

Summary
Power Supply
PR-850A (60A)
PR-850A (40A)
PR-300 (20A)