5
HARDWARE INSTALLATION
Be certain to follow standard anti-static procedures when handling any of Midian’s products.
For all diode protected inputs (i.e. PTT Input, Mode Input, COR Input) the voltage level to be required for a logic
low is less than 0.5 V and a logic high requires at least 2.1 V.
J1 – RJ-48 10-Pin Connector:
J1:1
–
Program In
: The KL-4 Option B or KL-4F-PC2 must be plugged in to access this pin for programming.
J1:2 – PL DIS
: Hook switch for mobile radio applications.
J1:3 – MIC
: Connect to the MIC+ connection on the radio’s external mic connector
J1:4 – Ground
: Connect to a ground connection on the radio’s external mic connector.
J1:5 – COR/LTR
: Future use.
J1:6– B+ (+3.5-8.0 VDC)
: This connection is only needed if not using the internal battery of the SM1. Connect to
B+ (3.5-8.0 VDC) connection on the radio’s external mic connector. If connecting to a mobile this must be
specified when ordering or you must install a 6.2 V Zener diode at D1 if the voltage is higher than 9.7 V. Connect
to a regulated voltage point in a vehicular radio if engine noise is present on the battery line. With D1 installed, the
voltage input could be as high as 15 VDC (nominal is 13.5 VDC). R-5 O Ohm resistor must be installed. Note: If
connecting this input DO NOT install the battery into the microphone and U1 must be removed.
J1:7 – PTT
: Connect to a PTT connection on the radio’s external mic connector used to key the radio. Some
radios look for a resistance on the microphone input to trigger PTT, R-50 in the SM-1 is used for this purpose and
will need to be picked on an individual radio basis. For Vertex radios this should be a 2.7 K resistor.
J1:8 – SPK Ground (SPK-)
: If connecting to a radio with a double ended speaker, then connect this line to the
negative side of the speaker connection on the external mic connector. If connecting to a radio with a single
ended speaker, this line is not connected.
J1:9 – SPK Hi (SPK+)
: Connect this line to the positive side of the speaker connection on the external mic
connector.
J1:10 – Program Out
: The KL-4 Option B or KL-4F-PC2 must be plugged in to access this pin for programming.
J2 – 3.5 mm Stereo Connector:
The 3.5 mm stereo connector on the SM1 is a dual purpose connector; charging and audio. The tip is 6V for
charging, ring is S and sleeve is ground. Use only Midian supplied wall power adaptors and audio
accessories for use with the SM1.
Charging:
To charge the unit, plug the Midian supplied wall power adaptor into an outlet and then plug the 3.5
mm plug into the 3.5 connector on the unit. When the LED is glowing green the unit is charging. When the LED
goes out then it is done charging. When the unit is in need of a charge the unit will emit a descending series of
tones to indicate low battery. Only use Midian provided accessories for charging.
Audio:
The 3.5 mm connector can be used as an audio accessory port (i.e. ear bud). The connections should be
ring as S and Sleeve as ground. Not using a Midian supplied audio accessory could result in damage to
the unit.
