3
HARDWARE INSTALLATION
Be certain to follow standard anti-static procedures when handling any of Midian’s products.
Connector P1
P1-1 – Green
– TX Audio Output – Connect to a high impedance audio point in the transmitter modulator.
P1-2 – Red
– 5.5 - 15 VDC – Connect to switched battery point in the radio.
P1-4 – Black
– Ground – Connect to the nearest ground plane in the radio.
P1-5 – Blue
– Speaker Output– Connect to the high side of the radio's speaker. The speaker completes the
ground for the emitter follower Q3. CAUTION: When attaching this lead to a 4 or 8 Ohm speaker, add a 100
Ohm resistor in series with this blue lead to limit current. When using 20-40 Ohm speakers, the onboard resistor
in series with Q3 should be sufficient.
P1-9 – White
– PTT Output – Connect to the PTT switch of the radio. The PTT Output gives an open-collector to
ground when activated and is rated at 100 mA continuous.
The remaining 8 wires are not connected.
HARDWARE ALIGNMENT
DTMF Output Level:
The DTMF output level can be adjusted for 0-750 mV RMS by adjusting R22. In a wide
band system, set R22 to 3.3 KHz (66% of 5 KHz) of deviation per EIA specifications. In a narrow band system,
set the R22 to 1.65 KHz (66% of 2.5 KHz) of deviation per EIA specifications.
R-22
