Furuno FAR 3220, Installation Manual

Page: 91 / 245

2. WIRING
2-49
With a waveguide and magnetron, however, mismatch of impedance causes “fre-
quency pulling.” For this reason, the number of possible mismatches in a waveguide
run, i.e., joins and bends, must be kept minimum.
• Each pair of flanges should be coupled with one O-ring, four bolts and spring wash-
ers and the choke flange must be in the upper position. The bolts and O-ring must
be greased before insertion to facilitate removal if required at a later date.
• The transceiver unit output flange is
a plain type and the Antenna Unit
output flange is a choke type, and it
is important to maintain this relation-
ship throughout the waveguide run.
• After installation of the waveguide is completed, the coupling portions must be
sealed by using the adhesive supplied.
• In a very short time the surface of the waveguide becomes green with verdigris.
Therefore, paint both the surface of the waveguide and flanges to avoid corrosion
and water penetration. Paint must not be allowed to reach the inner surface of the
waveguide or the mating surface of any flange.
2.8.3 How to connect the cables from S-band radar antenna
Antenna cable, serial cable, sub monitor
1. Loosen eight bolts then remove the cover of the unit.
2. Unfasten three bolts from the cable clamp. Lay the cables in their cable slots so
their armors rest in the slots.
3. Attach the appropriate WAGO connectors (pre-attached) to the appropriate ca-
bles, and then connect the antenna, sub monitor and serial cables to the RF-TB
Board shown in the following figure. For how to connect the WAGO connector,
see "WAGO connector" on page 2-5. For pin arrangement, see the interconnec-
tion diagram at the back of this manual.
Note 1: Make sure to pass the cable through the specified locking wire saddle.
Note 2: A terminal opener is provided on the RF-TB Board.
• Destination of Antenna cable
Power line : TB801 through the locking wire saddle (A).
LAN cable : J821 through the locking wire saddle (A)
Shield of power line : Screw (C)
Thru-deck hole
Weld here.
Deck
TRANSCEIVER
UNIT
Drain waveguide
Loosen eight bolts. Remove three bolts.
For Serial cable
For Antenna cable
For Sub monitor cable