At 09:43 AM 12/21/03 -0500, you wrote: >Thanks Mike, for drawing this up, for clarity the orange wire is the one >that should be held low to allow the steady tone output - if cycled it >will create the reverse burst that can be detected by an unknown group >of radios. And just like a fan delay or a ptt delay you could add a cap >to the cor signal but that won't help the discriminator detect >fluttering mobiles, that is a discussion for another day.
Actually the thinking behind the delay I suggested is that if the mobile flutters the PL encoder stays on a moment longer and "fills in the gaps", so to speak... if the signal comes back the encoder is still on. An RC time constant is just one way of adding the delay I mentioned and adding the cap to the cor signal just keeps the repeater itself keyed up longer (not my intent) >I have used 10, 15 and 20k resistors to make this circuit that Mike >has drawn, if the FET can switch quicker than a NPN then use it - that >answer may require a degree in advanced silicon applications, the NPN >has run for about 7 years near Lake Erie but your mileage will vary and >surely be shortened if sparks fall from the sky. > >Mike Morris WA6ILQ wrote: > > > > It's not that hard... > > Unfortunately I don't have a working test bench right now to do any > > engineering. If somebody wants to run with the idea below and do > > the breadboarding and write up the article I'd be glad to edit it, > > HTML-it, and post it. > > > > Basically you leave the encoder running all the time (Virden, it that > > what the orange wire you were referring to does?), and have two > > resistors in series between the encoder output and the TX modulator > > input. A FET goes from the center point to ground. You control the > > FET with the RX COR so that the encoder audio is pinched off when > > the RX squelch is closed. > > > > You can also use an ordinary NPN transistor in a pinch. > > > > You'll need Courier font for the diagram below. > > > > encoder > > output --\/\/\/--+---\/\/\/\/---- to TX modulator (usually > > ! the top of the dev pot (may > > ! need a DC blocking capacitor) > > ! > > +--! > > !<---\/\/\/---to controller output > > +--! or COR output > > ! > > gnd > > > > Personally, I'd not use the raw COR output - I'd add a little delay > > somewhere in the system so that a fluttery signal didn't flutter the > > PL encoder on and off.... Maybe use and RC network, or set up a > > logic output on the repeater controller with a 1/3 to 1/2 second delay > > > > and control the FET with it, and have a 2 to 3 second carrier delay > > (hang-in) timer on the repeater. > > > > End of problem. > > > > By the way, this trick has been around for 30 or so years - I first > > did it on > > WA6EWS's Mocom 35 to allow the PL encoder to be enabled or disabled - > > Moto > > had a T-filter using two resistors like the diagram above with a > > capacitor to > > ground... I used the front panel "extender" switch to short out the > > cap and disable > > the tone. > > > > Mike WA6ILQ > > > > At 01:16 PM 12/20/03 -0600, JOHN MACKEY <[EMAIL PROTECTED]> wrote: > > > > > Yes, that would be very good for a write up! > > > > > > "Chuck Kelsey" <[EMAIL PROTECTED]> wrote: > > > > > > > Why don't you write it up in some detail and submit to Kevin for > > > > posting on the Repeater-Builder web site? > > > > > > > > Chuck > > > > WB2EDV > > > > > > > > > > > > ----- Original Message ----- > > > > From: "Virden Clark Beckman" <[EMAIL PROTECTED]> > > > > To: <Repeater-Builder@yahoogroups.com> > > > > Sent: Saturday, December 20, 2003 8:19 AM > > > > Subject: Re: [Repeater-Builder] TS-64 > > > > > > > > > This is defeatable, I have described this several times - > > > instead of > > > > > turning off the tone generator thereby activating the reverse > > > burst just > > > > > use a hold low in between 2 15K resistors to pinch the pl output > > > of the > > > > > ts64 module going towards the modulator. To use this you will > > > have to > > > > > hold the orange wire low full time, and you will find the > > > switching time > > > > > is faster than the reverse burst. > > > > --------------------------------------------------------------- > > 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 the Yahoo! Terms of > > Service. > >-- >73...Clark Beckman N8PZD > >Pursuant to U.S. Code, title 47, Chapter 5, Subchapter II, ß227, >"Any and all nonsolicited commercial E-mail sent to this address >is subject to a download and archival fee of $500.00 U.S.". >E-mailing denotes acceptance of these terms. > > > > > >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/ 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/
