Installations; Antenna Wiring; Key Points To Installation Of Antenna; Requirements For T/R Antenna - Furuno FS-1575 Service Manual

1.2 Installations

1.2.1 Antenna Wiring

1. Key Points to Installation of Antenna

1) To install a self-supporting antenna, leave a space of not less than 5 m between the
antenna and structures including radar mast in consideration of bending of the
antenna caused by wind pressure.
Note: For details, refer to the antenna specification.
2) To install a self-supporting antenna, join the antenna element so as not cause itself to
come off. Apply a coating of silicon sealant to the area on which it is jointed.
3) Determine the tension of the lead-in in consideration of the deflection of lead-in
caused by the swing of the antenna. Too high tension results in the fracture of lead-in
connection. Too low tension causes the lead-in to come into contact with other
structures.
4) To connect the antenna lead-in to the antenna terminal of the antenna coupler, refer to
FQ5-2008-011 and FQ5-2006-010.
5) Make the ground of the antenna coupler as short as possible using a copper band of
50 mm or more in width. As a guide, take 1 to 10 or less as a ratio of width to length
of the copper band. For example, to use a copper band of 50 mm in width, the length
should be not more than 500 mm.

2. Requirements for T/R Antenna

A T/R antenna with capacitance of not less than 100 pF at 1.6 MHz is required. For
wiring, use a T/R antenna of not less than 10 m in length, such as AT-101 or AT-130.
To use an antenna of 8 m in length such as AT-82D/S, provide a lead-in of not less than
2 m in length.
Reference:
When the power supply turns OFF, the T/R antenna will be grounded through a
relay in the antenna coupler. If R.ANT is used, the T/R antenna will be grounded
when message is received.

3. Receiving Antenna Wiring Configuration

For a receiving antenna, a dedicated RX antenna can be connected, and also the T/R
antenna can be shared. In addition, the WR2 antenna can be shared as well.
For details, refer to information on pages 4-73 to -78.
1) Change the "TP connector" wiring on the RX FIL board.
2) Make setting as follows:
[MENU] -> 9. SERVICE -> 3. RT SETUP -> 1. SETUP -> Set DIVIDER to "ON"
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1.2 Installations