Why don't you simply use an MVP carrier control timer or duplicate the circuit that they used?
Chuck WB2EDV ----- Original Message ----- From: "Thomas Oliver" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, April 21, 2008 7:34 PM Subject: RE: [Repeater-Builder] Carrier Control Timer > There was an article in QST years ago about how to use a 555 timer for cor > and timeout timer with a hang timer, I actually built one and it worked. > I > think it would work in your situation. > > Maybe some kind soul could find it and post it. > > > tom > > >> [Original Message] >> From: w6jll <[EMAIL PROTECTED]> >> To: <[email protected]> >> Date: 4/21/2008 7:21:37 PM >> Subject: [Repeater-Builder] Carrier Control Timer >> >> With regard to Tom's use of a carrier control timer - I am using GE >> EXEC II and MVP's in my system. Although I have relied on the external >> controller's time out functions, I would like to have a "backup" timer >> in the transmitters that would take the repeater transmitter off the >> air at say 10 minutes, if for some reason the contoller circuit failed. >> I've looked at the 555 but the problem is that in the monostable mode, >> the pulse input to start >> the cycle has to be shorter than the timing cycle (according to some >> design notes, about 1/3rd or less). Obviously, this won't work for the >> intended application since the pulse (key down) would be longer than >> the timing cycle. I'm sure someone on the bulletin board has >> designed/implemented what I'm looking for. Any thoughts would be >> appreciated. TNX Fred W6JLL >> >> >> ------------------------------------ >> >> >> >> Yahoo! Groups Links >> >> >> >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG. >> Version: 7.5.524 / Virus Database: 269.23.2/1389 - Release Date: > 4/21/2008 8:34 AM > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
