I noticed the statement about the "low level (open collector) with 10mA sink current." It's never easy, is it? <wink>
-----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of skipp025 Sent: Tuesday, May 03, 2005 10:30 AM To: [email protected] Subject: [Repeater-Builder] Re: TKR-820 Controller Working from memory, I belive you're on the right track. Also keep in mind the COS output on the TKR-720/820 repeater is not a complete or true logic transistion. In short, the voltage on the COS pin doesn't go from zero to +12 volts or the converse. The level was something wacky value. I ende up making a level shift comparitor circuit, which detects the COS pin voltage change between no signal and a valid signal condition. I actually am in the process of having the circuit made into small boards, which I hope to offer up for sale pretty cheap... so others don't have to scratch their head to figure out a circuit. If you try to fudge something onto the COS pin, which exceeds the max value for the controller board logic, you take the chance of having the circuit go on vacation (fail). The repair of said damaged board will not be easy or fun. skipp Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
