Midland SD-250, Руководство пользователя, Страница: 9 / 20

Rev. 0B
8
Program: Read Note: If the option modem board is installed,
a resistor link can select RS-232 signal
levels. See Modem manual
Program : READ used for outputting
programming data from mode
RS-232 level (option)
+12V = Tx
-12V = Rx
TTL level only for
radio program
O/P
4 Ground Ground connection to chassis of the radio. 0V (Chassis)
5 B+ Power supply input (Nominal 12V) 9.0V – 18.0V DC
6 Busy
(CD)
Logic level output to indicate presence of a
carrier. (If required, link changes enable the
busy line to be active high)
Note: If the option modem board is installed,
a resistor link can select RS-232 signal
levels. See Modem manual.
TTL level
0V = carrier
5V = no carrier
RS-232 level (option)
+12V = carrier
-12V = no carrier
O/P
7 Microphone filtered
audio IN
Audio signal that is filtered (high pass and
pre-emphasis) then follows same route as
data mod through LPF. Sub-audio tone is
mixed with audio after the LPF.
Audio
1KHz audio at 60%
peak system deviation
input level =
6 to 8Vrms
I/P
8 Program: Write /
Serial command Used for inputting programming data and use
of serial command. TTL level I/P
9 Speaker filtered
OUT
Audio output from the audio amplifier.
Filtered by tone-filter and de-emphasis
circuit.
1KHz audio at 60%
peak dev. produces
Nominal 1Vrms @ 8
Ω
O/P