4
HARDWARE INSTALLATION
Be certain to follow standard anti-static procedures when handling any of Midian’s products.
P1-1 – Black
– Ground – Connect to the nearest ground point.
P1-9 – Red
– 5.5-18 VDC – Connect to switched B+ in the radio.
P1-3 – Gray
– COR/COS Input – Connect to point in the squelch or CTCSS circuit that changes logic level when
carrier is received.
P1-11 – Orange
– RX Tone Input – Connect to an audio point in the receiver, usually the high side of the volume
control or discriminator output. When using CTCSS, pick up the audio after the high pass filter.
P1-5 – Light Brown
– Monitor/Squelch Out – Connect to a point in the squelch circuit that normally changes logic
level with carrier. The squelch polarity is set in the MPS software and by selecting the polarity of D-5 by changing
its direction. R-65 can be changed to provide more or less current as needed. Do not allow the Monitor/Squelch
Output to conflict with the COR/COS lead input.
P1-12 – Blue
– Auxiliary/Emergency Input - When taken to Ground, this input can send Emergency or encode in
a secondary dialing format. This depends on the Auxiliary Input setting in the MPS software under the Control
tab. This lead can also be used to disable the transpond. The product comes from the factory setup for this
feature with JU6 installed.
This lead can also be used for the Deadbeat Disable function of the UED-1. When activated Q6 latches low until
commanded to unlatch. To activate this feature, uninstall JU6 and install JU7.
This blue lead can also be used for the Program Input by uninstalling JU6 or JU7 and installing JU8. This can be
connected to the monitor button, squelch pot switch, or the KL-4’s Green Lead.
P1-4 – Green
- Momentary Horn – When used as Horn, this provides a 0-9 second ground during ringing through
FET1 (500 mA).
P1-8 – Yellow
– TX Tone Out – Connect to the modulator circuit. Use high impedance point in the radio. If
generating CTCSS, use the CTCSS point in the modulator.
P1-2 – Violet
– Alert Tone/Speaker Audio – Connect to high side of the speaker. This provides Time-Out Timer,
Penalty, and Go Ahead tones. When using 20-40 Ohm speakers, the onboard resistor in series with Q5 should
be sufficient. When attaching this lead to a 4-8 Ohm speaker, add a 100-Ohm resistor in series with the lead to
limit current.
P1-6 – White
– PTT In – Requires a logic low from the radio’s PTT switch. If TOT is not needed, the PTT In &
Out wires can be tied together and connected directly across the radio’s PTT switch. For non-common PTT, open
the PTT path and connect the gray wire to the switch.
P1-7 – Dark Brown
– PTT Out – Connect to the other side of the open PTT path as referred to in the above step.
The UED now has control of the PTT for Time Out Timer (TOT) and penalty timer. The PTT transistor, Q4, is
rated at 100 mA continuous.
