Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
On 5/3/2010 12:08 PM, N1BUG wrote: I'm guessing I am not the first to want to do this... I want to use a UHF Micor for a link. I want to be able to stop the PL encode immediately when a user unkeys, but I want the controller to be able to hold the transmitter up (without PL tone) for sending IDs. There appears to be no PL on/off gate on the TLN5731A encoder. The only tone gate is Q703 which only gates the out of phase tone used for reverse burst. Other than using a mechanical relay to interrupt the encoder tone output, any suggestions? Thanks, Paul N1BUG The usual method we've used is to pull it to ground when you don't want tone with a transistor or a FET. You can remember though that, depending on your link rx, letting the Micor encode reverse burst will close the squelch quicker than just letting it coast. My experience is that the reverse burst on the stock Micor encode board works on the vast majority of radios, both Motorola and not. It worked on every Kenwood I had except for the old TK-801. Ham or commercial. The only other radio I have had in recnt years that it did not work on is the Yaesu VX-1R. Not even chicken burst works with that radio. I can't say for sure, but I think that if you key it with the PTT input, after the reverse burst delay, the tone will shut off...I could be wrong though...I'm sure there's a simple way to do it though. A one-transistor switch in the right place shoule do it.
RE: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
I'm guessing I am not the first to want to do this... I want to use a UHF Micor for a link. I want to be able to stop the PL encode immediately when a user unkeys, but I want the controller to be able to hold the transmitter up (without PL tone) for sending IDs. There appears to be no PL on/off gate on the TLN5731A encoder. The only tone gate is Q703 which only gates the out of phase tone used for reverse burst. Other than using a mechanical relay to interrupt the encoder tone output, any suggestions? Thanks, Paul N1BUG Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. --- Jeff WN3A
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
On 5/3/2010 1:08 PM, Jeff DePolo wrote: I'm guessing I am not the first to want to do this... I want to use a UHF Micor for a link. I want to be able to stop the PL encode immediately when a user unkeys, but I want the controller to be able to hold the transmitter up (without PL tone) for sending IDs. There appears to be no PL on/off gate on the TLN5731A encoder. The only tone gate is Q703 which only gates the out of phase tone used for reverse burst. Other than using a mechanical relay to interrupt the encoder tone output, any suggestions? Thanks, Paul N1BUG Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. --- Jeff WN3A Yeah-that's it! |cP
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Jeff DePolo wrote: Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. Thanks Jeff, I did notice P701 on the schematic. Any experience on whether a transistor will pull it low enough or do I need something better? Guess I'll try a transistor and see what happens unless I hear that won't work! Paul
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
wd8chl wrote: The usual method we've used is to pull it to ground when you don't want tone with a transistor or a FET. You can remember though that, depending on your link rx, letting the Micor encode reverse burst will close the squelch quicker than just letting it coast. My experience is that the reverse burst on the stock Micor encode board works on the vast majority of radios, both Motorola and not. It worked on every Kenwood I had except for the old TK-801. Ham or commercial. The only other radio I have had in recnt years that it did not work on is the Yaesu VX-1R. Not even chicken burst works with that radio. I can't say for sure, but I think that if you key it with the PTT input, after the reverse burst delay, the tone will shut off...I could be wrong though...I'm sure there's a simple way to do it though. A one-transistor switch in the right place shoule do it. Thanks. It looks to me like the stock encoder supplies PL tone to the transmitter continuously, whether PTT is active or not. The only exception I can see is that for ~150 milliseconds after PTT input to the encoder goes inactive, it switches to reverse burst - then back to regular PL tone. It seems like a mod to keep reverse burst but kill the regular PL tone while still allowing the controller to keep the transmitter up (without tone) for IDs would be more complex. Unless I'm overlooking something, which I've been known to do! Squelch tails are *probably* not going to be much of an issue since I plan to use AND squelch with PL and the infamous Micor carrier squelch at the receive end of the link. That Micor squelch chip really clamps off the audio quickly if it's a full quieting signal. If there is enough of a squelch click to annoy me I can just add an audio delay in the appropriate spot. Paul
RE: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
You can try a bipolar, but you might have some residual leakage which will show up as a low-amplitude distorted (clipped) waveform. I'm trying to remember what option card(s) used that P701 to kill the PL encode so I could look at the schematic to see what they're keying it with, but I can't remember. Maybe Eric knows off the top of his head? --- Jeff WN3A -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of N1BUG Sent: Monday, May 03, 2010 1:41 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A) Jeff DePolo wrote: Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. Thanks Jeff, I did notice P701 on the schematic. Any experience on whether a transistor will pull it low enough or do I need something better? Guess I'll try a transistor and see what happens unless I hear that won't work! Paul No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.814 / Virus Database: 271.1.1/2842 - Release Date: 05/03/10 02:27:00
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
N1BUG wrote: Squelch tails are *probably* not going to be much of an issue since I plan to use AND squelch with PL and the infamous Micor carrier squelch at the receive end of the link. DUH! Not my best day... Looks like I will end up killing squelch crashes with an audio delay in any case, since there will be occasions the transmitter stays up after the tone drops (during IDs). Unless, of course, I figure out a way to keep the reverse burst capability while still allowing the controller to keep the transmitter up with *no* tone after the reverse burst. Paul
RE: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
I have a question for the group. What is reverse burst? And when is it used? Motorola radios. Leroy. J39AI. -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of N1BUG Sent: Monday, May 03, 2010 1:54 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A) wd8chl wrote: The usual method we've used is to pull it to ground when you don't want tone with a transistor or a FET. You can remember though that, depending on your link rx, letting the Micor encode reverse burst will close the squelch quicker than just letting it coast. My experience is that the reverse burst on the stock Micor encode board works on the vast majority of radios, both Motorola and not. It worked on every Kenwood I had except for the old TK-801. Ham or commercial. The only other radio I have had in recnt years that it did not work on is the Yaesu VX-1R. Not even chicken burst works with that radio. I can't say for sure, but I think that if you key it with the PTT input, after the reverse burst delay, the tone will shut off...I could be wrong though...I'm sure there's a simple way to do it though. A one-transistor switch in the right place shoule do it. Thanks. It looks to me like the stock encoder supplies PL tone to the transmitter continuously, whether PTT is active or not. The only exception I can see is that for ~150 milliseconds after PTT input to the encoder goes inactive, it switches to reverse burst - then back to regular PL tone. It seems like a mod to keep reverse burst but kill the regular PL tone while still allowing the controller to keep the transmitter up (without tone) for IDs would be more complex. Unless I'm overlooking something, which I've been known to do! Squelch tails are *probably* not going to be much of an issue since I plan to use AND squelch with PL and the infamous Micor carrier squelch at the receive end of the link. That Micor squelch chip really clamps off the audio quickly if it's a full quieting signal. If there is enough of a squelch click to annoy me I can just add an audio delay in the appropriate spot. Paul
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Would this still allow the reverse-burst to pass through, or just abruptly cut off? On 05/03/2010 12:14 PM, wd8chl wrote: On 5/3/2010 1:08 PM, Jeff DePolo wrote: I'm guessing I am not the first to want to do this... I want to use a UHF Micor for a link. I want to be able to stop the PL encode immediately when a user unkeys, but I want the controller to be able to hold the transmitter up (without PL tone) for sending IDs. There appears to be no PL on/off gate on the TLN5731A encoder. The only tone gate is Q703 which only gates the out of phase tone used for reverse burst. Other than using a mechanical relay to interrupt the encoder tone output, any suggestions? Thanks, Paul N1BUG Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. --- Jeff WN3A Yeah-that's it! |cP
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Leroy A. M. Baptiste wrote: I have a question for the group. What is reverse burst? And when is it used? Motorola radios. Leroy, I'm sure others can explain it better, but... Reverse burst was / is used by Motorola and others to eliminate squelch crashes at the receiving end of a comm circuit. It works like this: after a transmission, the transmitter stays keyed momentarily, during which time an out-of-phase version of the PL tone is transmitted. This out-of-phase tone causes the tone decoder at the receive end to shut off audio before the transmitter carrier disappears. Someone will correct my errors here :) This might help: http://www.repeater-builder.com/rbtip/reverseburst.html Paul
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Tony KT9AC wrote: Would this still allow the reverse-burst to pass through, or just abruptly cut off? Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. Grounding pin 701 would kill the tone entirely, including reverse burst. Which is what I asked for... although now I feel on the verge of getting a clue about how to keep reverse burst and still do what I want...maybe! Paul
RE: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Hi Paul, thanks, I think that answers my question adequately. In other words if I am using an open repeater without PL tones, I do not need reverse burst? -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of N1BUG Sent: Monday, May 03, 2010 2:30 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A) Leroy A. M. Baptiste wrote: I have a question for the group. What is reverse burst? And when is it used? Motorola radios. Leroy, I'm sure others can explain it better, but... Reverse burst was / is used by Motorola and others to eliminate squelch crashes at the receiving end of a comm circuit. It works like this: after a transmission, the transmitter stays keyed momentarily, during which time an out-of-phase version of the PL tone is transmitted. This out-of-phase tone causes the tone decoder at the receive end to shut off audio before the transmitter carrier disappears. Someone will correct my errors here :) This might help: http://www.repeater-builder.com/rbtip/reverseburst .html http://www.repeater-builder.com/rbtip/reverseburs t.html Paul
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
That's right Leroy, reverse burst was invented to overcome the problem of tone decoders being relatively slow to realize the tone went away and thus producing a somewhat long burst of noise before muting the speaker. Paul Leroy A. M. Baptiste wrote: Hi Paul, thanks, I think that answers my question adequately. In other words if I am using an open repeater without PL tones, I do not need reverse burst? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Thanks again Paul, I really do appreciate it. -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of N1BUG Sent: Monday, May 03, 2010 2:50 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A) That's right Leroy, reverse burst was invented to overcome the problem of tone decoders being relatively slow to realize the tone went away and thus producing a somewhat long burst of noise before muting the speaker. Paul Leroy A. M. Baptiste wrote: Hi Paul, thanks, I think that answers my question adequately. In other words if I am using an open repeater without PL tones, I do not need reverse burst? Yahoo! Groups Links http://groups.yahoo.com/group/Repeater-Builder/ http://groups.yahoo.com/group/Repeater-Builder/joi n (Yahoo! ID required)
