Attached is a circuit I have used several times to combine two receivers into one output. I have used it for adding a control receiver to a repeater controller as well as two remote base radios into a single port on a repeater controller, but it can be used to add a second input to a controller for two repeaters in parallel.
As Bob indicated, just put the transmitter PTT and audio in parallel, and use this circuit to combine the two receivers and COS signals into single audio and COS signals for the input of your controller. If you are not using GE equipment, just make sure the COS signals are around 8 to 9 volts from each receiver when interfaced to this circuit. If you only have 5 volt COS signals reduce the supply voltage to the circuit to 5 VDC to use the lower voltage inputs. 73 - Jim W5ZIT --- On Sat, 10/18/08, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Subject: Re: [Repeater-Builder] Two repeaters, one available port. To: [email protected] Date: Saturday, October 18, 2008, 6:21 PM At 10/18/2008 08:56, you wrote: >At 07:32 AM 10/18/2008, John Everson wrote: > > >Good morning to the group. > > > >I have a situation where I have two repeaters and only one available > >port. Has anyone tried this? If so, what method did you use, and what > >were the results? I have done this in the past, but it was a long time > >ago, and my memory isn't what it used to be. It seemed to work, but > >back then, I may have not really have been as discriminating as I am > >today. > ><----What kind of "port" are you talking about? Antenna? Controller? I assume he's referring to repeater controller ports. I believe you can simply tie the PTT & audio out of a single port to 2 transmitters. Just make sure the open PTT voltage of both transmitters is roughly the same. If one is 5 volts & the other is 12, the 12 volt source could damage the 5V PTT line. The receivers are a different story, as you'll need some sort of port combiner to handle the COS & CTCSS logic outputs & audio outputs from the 2 receivers. I built a 4 port unit that logically ORs all 4 COS lines & squelch gates/mixes the audio from each receiver. Unfortunately I never scanned the circuit so I'd have to rummage through my paper files if you're interested in the schematic. Bob NO6B _._,___ __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Combiner.pdf
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