Mods for ADI AR-247 220mhz and the AR-447 440mhz mobile radio for COR to Repeater links..
vcc depends on required logic levels needed..normally 5 volts.
the circuit below is ADDED into the radio to invert the logic..and is not Q29 of the radio.
Shown above is the inverter needed for a high during active COR, output depends on the vcc input voltage..I use 5volts.
Shown below is the blue wire, the junction of R104, R105 and U4 Pin11.. this is the point of COR
COR OUTPUT from the added circuit goes to the repeater controller
This will allow the correct COR logic needed for most repeater controllers.
Other signals such as RecAudio, PTT and Microphone can be taken from the microphone jack in front of radio..
I use several of these ADI 220mhz units for links and they work great..
the Voltage at COR is 5volts(logic high) when squelch is closed.. near .2volts(logic low) when squelch is open..
please note: do this mod at your own risk..