I have had good luck using an opto isolator to interface a radio that I don't have the internal schematic for. The radio usually has a LED indicator for receive, and is easy to find. Place the diode section of a 4N36 isolator in series with the receive indicator LED and the transistor portion of the 4N36 will allow interface to your controller. It provides an open collector closure to the emitter when the LED on the radio is lit. Applying +5 or +12 volts to the collector will provide a positive going output on the emitter of the 4N36 when the LED is lit.
73 - Jim W5ZIT -----Original Message----- From: [EMAIL PROTECTED] To: [email protected] Sent: Thu, 18 Jan 2007 10:59 PM Subject: [Repeater-Builder] COS output for Kenwood I have a TM-431A which I want to use as a half-duplex link. I can easily get audio in and output, but I'm stumped on how to get a voltage change when the squelch opens for COS (Carrier-operated-squelch) Ideally I'd like a voltage that swings only when the CTCSS is detected as well as squelch open, but I'd settle for one that is just the squelch. My controller is an ICS linker. Does anyone know the proper point to connect to, or does anyone have a service manual for this unit? Thanks, Jeff WB0LRX ________________________________________________________________________ Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
