Sigtronics SPCC-2 - Manual (Page 7)

FM RADIO INTERFACE CABLE WIRING
The following are some examples of possible wiring
schemes for the FM interface cable. Only the FM
radio functions are shown for the FM radio end of
the interface cable, because the connector(s) used
by radio manufacturers varies widely. You will
have to consult the radio manual or manufacturer
for the connector(s) used and pin assignments
for your particular FM radio. Also, Sigtronics has
extensive radio interface experience and can assist
in any question you might have concerning this or
any other aspect of the SPCC. Of course, Sigtronics
can build a FM interface cable for you to your
specifications, if desired.
Figure 3 shows the most common of such cables
with its “high level mic input” and standard “ground
to key” interface. This cable will work with most
standard police, fire, and business band radios as
well as aircraft type radios.
Figure 4 is similar to Figure 3 but is used for radios
requiring a low level mic input such as marine type
radios.
Figure 5 shows typical cable wiring for radios that
sense the presence of mic current to transmit. Most
ICOM hand-held radios are set-up this way.
FIGURE 3
SPCC
Pin #
FM RADIO
1
2
4
3
5
Mic Audio Input
Ground
Headphone Audio
Output
Transmit Key Input
FIGURE 5
SPCC
Pin #
FM RADIO
1
2
3
4
5
Headphone Audio
Output
Ground
Transmit Key Input
FIGURE 4
SPCC
Pin #
FM RADIO
1
2
4
3
5
33K *
1K *
Mic Audio Input
Ground
Headphone Audio
Output
Transmit Key Input
* Use 1/8 or 1/4 watt resistors
FIGURE 2
Male five pin connector shown from solder side:
PLUG END SOLDER END
1
2
3
4 5
1
2
3
4 5
FM RADIO INTERFACE CABLE WIRING
FM Radio Interface Cable Connector
Pin Assignment
Pin Function
1 Mic audio output to FM radio
3 Receive audio input from FM radio
4 FM radio ground
2,5
Transmit key output to FM radio (Normally
open relay contacts closed during FM ra-
dio transmit)
Page 7