Maxon SD170EX Series - Interfacing; External Connections; DB- 9 PIN Descriptions with Input;Output Level

Service Manual SD170EX Series
Page 27 of 38
Interfacing
External connections
Connection is made to the SD170EX via an external 50 ohm BNC socket (RF signal) and a high
density 9-way “D”-type socket (DB-9 connector; control and data signals) with 4-40 UNC threaded
jack posts for more permanent connection. Besides,
DB-9 Pin includes “Power”. The data communication during PC program is used through one pin
so that the application design should be considered for the pin when you use the applied circuit
which is made on your way.
DB- 9 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
Ground. Ground.
DC 0V
5 Power Power connection to Out of the radio. DC +12V
6
Serial Data Out
Serial data output for radio control or
program. It uses asynchronous data
format.
TTL level 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
Serial command or data input and
data output for radio control or
program. It uses asynchronous data
format.
TTL level I/O/P
9
Speaker filtered
OUT
Audio output from the audio
amplifier.
It’s filtered by tone-filter, de-
emphasis circuit.
Audio
1KHz audio at 60%
peak system
deviation produces
Nominal 1Vrms @
8Ω
I/P
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