Pwr (Rf) Board (03P9348) - Furuno FAR-2107 Series Service Manual

7.2.5 PWR (RF) board (03P9348)

The PWR (RF) board has different parts for X-band and S-band radars and is not
compatibly used for different band radars.
Name of
PWR(RF)
03P9348A
03P9349B
03P9350C
When supply voltages are supplied from the Processor unit, line voltages drop by the
antenna cable. It causes differences in potential on the ground between the Processor
unit and Antenna unit, thereby resulting in unstable voltage on the earth lines of cables.
For this reason, the power supply to the Antenna unit is featured as follows:
The power to the Antenna unit is supplied in +24 VDC alone except for the TX-HV and
motor line. Required voltage is generated in the Antenna unit based on this power
supply.
Connection of negative line for GND:
For TR unit power supply: +24 VDC
For motor power supply:+24 VDC
(X-band radar)
For TX-HV power supply: 500V
SW REG.
Applicable
radar type
JP21
X band
Open
6/12 kW
X band 25 kW Open
S band 30 kW Short
RPU-013
PWR p.c.b
REC
SW REG.
HV p.c.b
TX HV
REC
Fig. 7.2.13 Earth Line of HV and +24 V Lines
Table 7.2.3 Differences of PWR(RF) board
Difference
Heater V
R29
(Short pulse)
2.2 k
2.2 k
3.3 k
RPU-013 unit side
No
Yes
Yes
ANT unit
RF PWR p.c.b
+24V
(L1)
FILTER
-24V
CR2
(D4F60)
MD p.c.b
7-18
7.2 Antenna Unit
Heater V
(Long pulse)
7.5 V ----
8.3 V 7.0 V
9.5 V 7.7 V
TR unit side
Yes
No
No
+5V
REG
Low
Voltage
Protect