There was an earlier post concerning grounding a pin on the backplane which instantly disables the PL tone on the transmitter. I've got a VHF unified chassis MICOR which is controlled by an SCOM 7K controller. I used one of the digital outputs of the controller and tied it directly to the PL disable connection on the backplane.
Then, I programmed a macro which was tied to a command function to have the line go low 1 or 2 seconds just before the transmitter shuts down. I works flawlessly. I don't have the manual or the code in front of me, but if anyone is interested in this I can provide details. Obviously you would need either a controller or some type of interface to accomplish this. 73, Don, KD9PT ----- Original Message ----- From: "N1BUG" <p...@n1bug.com> To: <Repeater-Builder@yahoogroups.com> Sent: Monday, May 03, 2010 3:30 PM Subject: Re: [Repeater-Builder] IDEA? Re: Micor PL encoder modification (TLN5731A) > Thanks Jeff! > > Having someone to kick this around with is helping. > > Very good point about the ratty user signal. I hadn't thought of that. > > You are exactly right. I need to make sure the controller is set up > to always keep the transmitter up for a short time after loss of > user signal on the repeater, and just kill the tone. > > Paul > > > Jeff DePolo wrote: >> >> >> >> I don't have a schematic in front of me, but if your plan is to key >> voltage >> to the board on/off, this won't work ideally because the vibrasender reed >> takes a little time to "come up to speed". >> >> Since the repeater transmitter is still keyed long after a user unkeys, >> just >> muting the encoder seems like it would work fine all by itself. Whether >> the >> radio does or does not understand reverse-burst shouldn't matter. RB >> would >> mute the receiver quicker on radios that do understand RB, but unless >> your >> courtesy tone, ID's, etc. start to be played out very quickly (like >> within a >> few hundred ms) of a user unkeying, even radios looking for RB should >> mute >> before those ID's and CT's air. >> >> Also consider what happens if a user is noisy/ratty/fluttery into the >> repeater. As the COR briefly goes inactive during a fade, you're going be >> switching PL phases. This will tend to make the user sound even more >> choppy >> on listener's radios that are using PL decode. You'd be better off not >> having the phase change, and just having the PL drop out briefly without >> RB, >> and then recovering in-phase when COR goes active again - less chance of >> having the user radio mute intermittantly. >> >> --- Jeff WN3A > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
