You can either build a COS inverter or use an aftermarket squelch board. Also you can try the LM386 amplifier for the audio.
See the following: http://www.repeater-builder.com/pix/cosinverter2.gif http://www.repeater-builder.com/projects/remotebasecos.html http://www.repeater-builder.com/projects/audioamp.html On Mon, Jul 13, 2009 at 6:42 AM, John Transue<[email protected]> wrote: > I need to interface a link receiver (Icom F221S) with an ACC RC-850. > This presents two problems. First, the Icom receiver uses active low > COS, and the RC-850 doesn't seem to have a means to select the sense > of a link receiver. The repeater receiver (Midland BaseTech II) uses > active high COS. Second, the discriminator audio output from the Icom > is about 0.6 Vp-p, but the RC-850 hardware manual says the audio input > should be between 1 and 5 Vp-p. > > I have posted the first problem to the ACC group but have received no > reply. Yes, the ACC manual says to insert a 47K resistor in a > specified place to increase sensitivity. I can do this but it requires > I take the repeater out of operation for a day or so. > > It occurs to me that a circuit to reverse the sense of the COS might > be available from this group. Also, a simple amplifier circuit could > solve the AF level problem. I know this is all elementary, but I am > not competent to design these simple circuits. I will gladly build > them. I would appreciate any help you can provide on the design. > > Thanks. > > John Transue AF4PD > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
