Q38. I Would Like To Know Precautions; Q39. How Much Collector Current Passes Through Pa At The Rated Output - Furuno FS-1575 Service Manual

Q36. I would like to know the size of a cable used to connect between the
Transceiver unit and the power supply unit.
A36. The size of a power supply cable size should be determined by its length. You
should select a power supply cable capable of maintaining a voltage drop in the
cable within 5%.
For example, if the cable is 10m in line length, approx. 30A of current passes
through the FS-2575 and approx. 55A of current through the FS-5075. As a result,
the suitable cable size will be 10 or 16 square mm for the FS-2575 and 16 or 25
square mm for the FS-5075.
As for power supply input voltage, it is more advantageous to apply 220VAC than
100VAC because 220VAC can keep input current at low level.
Q37. I would like to know the size of a cable used to connect between the battery
and the battery charger.
A37. The FS-5075 and FS-2575 systems use the PR-850A power supply unit to output
the Main Fail signal. When the main fail function gets activated, the FS-5075
outputs 25A of current, while the FS-2575 outputs 15A of current. The maximum
charge current of BC-6158 is 30A. Consequently, you should select a power
supply cable capable of maintaining a current level at 30A and voltage drop in the
cable within 5%. The suitable size will be not less than 25 square mm if the cable
is 20m in line length, or not less than 35 square mm if it is 30m in line length.
Q38. I would like to know precautions for using a copper band for grounding
ATU.
A38. Basically, you should use a copper band with iron plate to ground the ATU. You
should make the grounding copper band as short as possible to prevent it from
swaying due to vibration or wind pressure, resulting in fracture. Furthermore, it
should be considered that the grounding copper band becomes eroded to cause
fracture.
To be more precise, you should weld a 6-mm bolt near to the ATU mounting
section and connect the copper band to the bolt with IV cable of 25 square mm in
size. With this, user can facilitate temporary grounding work. It's just recommend.

Q39. How much collector current passes through PA at the rated output?

A39. Approximate TX output power can be calculated by using the equation
"Po = PA IC × PA VC x η"
PA VC
FS-5075(500W) 42V
FS-2575(250W) 42V
FS-1575(150W) 24V
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.
PA IC Efficiency (η)
(1-tone) (1-tone)
18 to 25A 60 to 45%
9 to 14A 60 to 45%
9-6
Chapter 9 Q&A
See page 1-7
See page 1-7
See AP4-1
Input Current Power
at 24V Supply
PR-850A
45 to 55A
(60A)
PR-850A
25 to 30A
(40A)
PR-300 (20A)