Service manual

Service Manual SD170E Series
Page 29 of 44
Interfacing
External connections
Connection is made to the SD170E via an external 50 ohm BNC socket (RF signal) and a high
density 15-way “D”-type socket (DB-15 connector; control and data signals) with 4-40 UNC
threaded jack posts for more permanent connection. Besides,
DB-15 Pin includes “Power”. The date communication during PC program is used through one pin
so that the application design should be considered for the pin when the you use the applied
circuit which is made on your way.
DB-15 PIN descriptions with input/output level
D - Type
Pin No.
Function
Description
Signal Type
Input/
Output
1
Data modulation
IN
(TX Mod)
Signal is directly injected to MOD
through data low pass filter without
pre-emphasis.
Analog signal
1KHz audio at 60%
peak system
deviation
input level =
100 to 120mVrms
I/P
2
Data unfiltered
OUT
(RX disc)
Discriminator audio from the SD-160.
This is the unprocessed AF signal
prior to tone filtering and de-
emphasis.
Analog signal
1KHz audio at 60%
peak system
deviation produces
200 to 300mVrms
O/P
3
PTT In
(TX Key)
Signal from the „external device‟ to
key the SD-160 transmitter.
This line has an internal pull up
resistor to +5V. Pulling the line to 0V
turns on the transmitter.
Note: If you installed option
modem board, you can select RS-
232 signal level by Jumper
(CON407) on the digital board. See
Figure 8.2.
TTL level
0V = Tx
o/c = Rx
RS-232 level
(option)
+12V = Tx
-12V = Rx
I/P
4
Power
Power connection to Out of the radio.
DC +12V
5
Serial Data Out
(TXD)
Serial data output for radio control or
program. It uses asynchronous data
format.
TTL level
O/P
6
Busy
(CD)
Logic level output from SD-160 to
indicate whether a carrier is present
or not
Note: If you installed an option
modem board, you can select RS-
232 signal level by Jumper
(CON407) on the digital board. See
Figure 8.2.
TTL level
0V = carrier
5V = no carrier
RS-232 level
(option)
+12V = carrier
-12V = no carrier
O/P
7
Microphone
filtered audio IN
This signal is injected to the MOD at
the point through audio-amplification,
pre-emphasis and high pass filtering
where sub-audio tone is mixed with
audio.
Audio
1KHz audio at 60%
peak system
deviation
input level =
6 to 8Vrms
I/P
8
Serial data
IN/OUT
(RXD/TXD)
Serial command or data input and
data output for radio control or
program. It uses asynchronous data
format.
TTL level
I/O/P