Khz If Rx Signal - Furuno FS-1575 Service Manual

Signal Name
CLK RX DDS / PLL IC clock signal/
DATA RX Frequency data set to DDS / PLL IC
UNLOCK RX Unlock signal of PLL circuit/
ST DDS RX Data set strobe signal to DDS/
ST PLL RX Data set strobe signal to PLL/
DDS IOUP RX Transfers data to the internal memory of the DDS.
DDS RESET RX Resets the DDS.
5V Power supply voltage for circuit.
AGC RX AGC control voltage under hardware control.
Bypasses the 1st amplifier of the RX board. Setting the RX attenuator to
RX ATT
"ON" will drop the reception gain by approximately 10dB.
36-kHz IF signal. This signal is demodulated by the DSP of the T-CPU
IF RX H/C
board.
Displays RX board version information when selecting [MENU] ->
RX HW VER0, 1
9.SERVICE -> 5.TEST -> 1.VERSION.

1. 36 kHz IF RX signal

The 36-kHz IF RX signal is inputted to the T-CPU board, and demodulated and
processed there. For details, refer to information on page 7-57.
200mV
(rms)
150mV
100mV
50mV
-10 0
Fig. 7.3.7 Example of 36-kHz RX IF Signal Input vs. Output Characteristics
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.
10 20 30 40 50
SSG Level
7-46
Table 7.3.5 Major Signals of RX Board
Function
SSB 2M
60 70 80 90 100
7.3 Receiver Circuit
dBuV
110