Thanks for the ideas... I'll have to check on the Relm I have and see if she has a 'busy' indicator, thinking it does, should have some 4N25's or similar laying on the bench somewhere from another project, fortunately the controllers aren't fussy and can use either + or - for COS.
I was trying to avoid using the speaker audio but it looks like that might be the easiest choice right now unless I can find something better between now and next week. Thanks, Dave - N0TRQ -- Every electronic device is manufactured with smoke stored deep inside... only a true genius can find a way to set it free. On Thu, Jul 3, 2008 at 9:18 AM, Jim Brown <[EMAIL PROTECTED]> wrote: > I have had good success in obtaining a COS signal from an 'unknown > circuit' by opening the lead to the front panel LED that indicates receive > activity. Place the diode of an opto isolator in series with the LED and > then use the transistor section of the opto isolator in your circuit as the > COS signal. You can use the transistor to pull up a resistor to a positive > voltage if you need a positive going COS ( with the other end grounded) or > you can pull a resistor to ground for a negative going COS (with the other > end connected to a plus voltage ). > > I have no idea if your radios have this front panel activity LED, but most > do. The PTT and mic inputs are pretty straightforward, and the speaker > audio can be used in a pinch, if the knob is removed from the audio gain > control to discourage folks from 'tweaking'. > > 73 - Jim W5ZIT > > > --- On *Tue, 7/1/08, dakaratcaptivereefing <[EMAIL PROTECTED]>* wrote: > > From: dakaratcaptivereefing <[EMAIL PROTECTED]> > Subject: [Repeater-Builder] RELM SMUxx Link Radio? > To: [email protected] > Date: Tuesday, July 1, 2008, 12:42 PM > > I've recently been tasked to link a couple of VHF repeaters with a UHF > link.. not too difficult, however the link radio's provided are Relm > SMUxxxx's, they are all programmed and ready to go. > > I'm just having trouble finding any good docs on locations to tap for > Rcv/Tx audio and maybe COS in these radios. > > On the plus side, I've bought an extra controller for myself and have > an extra mobile rig of the same model to experiment with before > tackling the repeaters... might as well make a mobile remote base for > my RV to play with while out fishing etc... > > Can anyone recommend a good starting point or some docs? Even better I > like pics :) > > Thanks > Dave - N0TRQ > > > > --
