JRC JSS-296 -, Руководство по обслуживанию

Страница: 98 / 220

6.5.1 Descriptions
The tuner consists the PA control, the matching unit and CS unit. The PA control controls the
tuning and store the tuning data for each channel. The matching unit consists the forward/return
wave sensor, antenna current sensor, Ci, L, Co, Cp, Cs and relays. The CS unit ground the
antenna when the RBK signal is not activated (High).
In case of the NFC-296 there is no CS unit. The Cs capacitance in the matching unit is always
passed when the RBK signal is not activated to ground the antenna through the T2 in the
matching unit.
When tuning the tuner check the VSWR by the preset tuner setting. If the VSWR is over than
about 1.7, the tuner starts the tuning otherwise keeps the preset setting.
6.5.2 Signals from/to the other units.
From/
To
Connecter
Name
Pin
No.
NQD-
4190
Console
terminal
Signal
name
Description
1 1 55, 56 +12V DC power source for the tuner.
2 2 57, 58 GND DC power return.
3 3 59 TXD Serial data transmission.
4 4 60 RXD Serial data reception.
5 5 61 -PA MUTE
Prohibit the transmission of the
Transceiver.
TB1
6 6 62 ANT CURR Antenna current analog data.
TB10
(NFC-896)
7 6 RBK
The antenna grounded at the CS UNIT
when not activated (High).
J2
(NFC-296)
1 7 6 RBK
The antenna grounded through the
tuner when not activated (High).
TB 3 Coaxial cable center conductor
PA
NAH-
692
695
698
TB 4
M-J-J RF OUT RF OUT
Coaxial cable shield
94