Ok, enjoy, Neil
---- Original Message ---- From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Mitrek COS ? Date: Fri, 19 May 2006 12:13:02 -0400 >Hi Richard and Neil... >In my instance, it floats between 3 and 3.5 volts.... which is just >enough >to confuse my controller as to which state the squelch is actually >in. > >Both approaches would probably work just fine... but haven't had a >chance >to deal with it yet. > >I can think of a number of instances when one might want to disable >the >input tone. I haven't had a need to so far, so the issue hasn't been >resolved as of yet. > >During the summer is when most station owners want to do maintenance >on >AM-Directional systems, so my days have been pretty full of late. ><grin!> > >Thanks for the ideas though.... I will check into it once I get a >chance.... > 73 >Mike Perryman >www.k5jmp.us > > -----Original Message----- > From: Repeater-Builder@yahoogroups.com >[mailto:[EMAIL PROTECTED] Behalf Of >[EMAIL PROTECTED] > Sent: Friday, May 19, 2006 11:22 AM > To: Repeater-Builder@yahoogroups.com > Subject: Re: [Repeater-Builder] Mitrek COS ? > > > > > Mike Perryman wrote: > > I was having trouble with my micor in that the COS signal would >never >go completely to zero volts... > > Mocom-70 was good for that too .. my solution came from a >fire-alarm >controller: > Details are fuzzy, but ~ it used some dual-input flip-flop >comparator chip >(7476 ?) ... sample (waffle-voltage) on one input & a reference on >the >other. > When the relative voltages reversed, made for a nice clean on-off >at the >output, and a xstr follower allowed for switching some juice... > > /. > > > > Hmmm ... I have run into this problem in the past ... I fixed it > > by biasing the emitter of the first (external) transistor off > > ground with a voltage divider .. or sometimes by placing a diode > > in series with the emitter. > > One time - I think it was a Standard land-mobile radio, the COS > > feed (aka squelch detector) was several volts above ground. In > > that instance, I installed a voltage divider between A+ and ground > > - to positive bias the added transistor above ground so when the > > squelch opened, the sense lead to the external transistor turned > > it on. > > Make sense? > > Neil > > > > > > > > > > > > >--------------------------------------------------------------------- >------- >-- > YAHOO! GROUPS LINKS > > a.. Visit your group "Repeater-Builder" on the web. > > b.. To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > > c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of >Service. > > >--------------------------------------------------------------------- >------- >-- > 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/
