Re: [Repeater-Builder] MICOR Squelch clones
At 10/22/2009 19:15, you wrote: I disagree that an audio delay board negates the positive effect of a MICOR squelch. ...and let's not forgot that many simply don't like ADMs. Ever try to operate full-duplex with a quarter second delay on the repeat audio? Also if the squelch chops the signal at all, an ADM set to a long delay can turn those muted valleys into muted peaks, creating a problem with the squelch where none existed before. Bob NO6B
Re: [Repeater-Builder] MICOR Squelch clones
n...@no6b.com wrote: At 10/22/2009 19:15, you wrote: I disagree that an audio delay board negates the positive effect of a MICOR squelch. ...and let's not forget that many simply don't like ADMs. Ever try to operate full-duplex with a quarter second delay on the repeat audio? Also if the squelch chops the signal at all, an ADM set to a long delay can turn those muted valleys into muted peaks, creating a problem with the squelch where none existed before. Bob NO6B This is where the MICOR squelch shines. If you ever heard a UHF repeater with a poor carrier squelch (kendecom comes to mind), no matter how loose the squelch is set, mobiles in deep flutter chop up the audio. The human brain is not as good at putting broken words together where the break is a total dead absence. On the contrary, if the broken word is bridged with noise, the brain can fill in the blanks, and a severely broken sentence can make sense. While this problem is worse on UHF where close spaced deep nulls can occur more frequently, the situation exists on VHF as well. Motorola did a lot or research on this subject during the Space Program of the late 1960's. The result is the MICOR squelch many try to replicate. If anyone that is interested in this subject would like to learn more about the what the Motorola engineers take on it was, I suggest you get a copy of a MICOR manual and read the theory. Kevin Custer
Re: [Repeater-Builder] MICOR Squelch clones
On Fri, Oct 23, 2009 at 9:21 AM, Kevin Custer wrote: n...@no6b.com wrote: At 10/22/2009 19:15, you wrote: I disagree that an audio delay board negates the positive effect of a MICOR squelch. ...and let's not forget that many simply don't like ADMs. Ever try to operate full-duplex with a quarter second delay on the repeat audio? Also if the squelch chops the signal at all, an ADM set to a long delay can turn those muted valleys into muted peaks, creating a problem with the squelch where none existed before. Bob NO6B This is where the MICOR squelch shines. If you ever heard a UHF repeater with a poor carrier squelch (kendecom comes to mind), no matter how loose the squelch is set, mobiles in deep flutter chop up the audio. The human brain is not as good at putting broken words together where the break is a total dead absence. On the contrary, if the broken word is bridged with noise, the brain can fill in the blanks, and a severely broken sentence can make sense. While this problem is worse on UHF where close spaced deep nulls can occur more frequently, the situation exists on VHF as well. Motorola did a lot or research on this subject during the Space Program of the late 1960's. The result is the MICOR squelch many try to replicate. If anyone that is interested in this subject would like to learn more about the what the Motorola engineers take on it was, I suggest you get a copy of a MICOR manual and read the theory. Kevin Custer Kevin, Thanks for that explanation... you're spot-on with your observation about how difficult it is to understand spoken-word chopped up Kendecom style! My system is on VHF, but exhibits exactly the behavior you describe and it's very difficult if not impossible to make any sense out of what is being said. Before you explanation, I could not rationalize why, but it makes good sense now. Eventually I'll try putting a Micor squelch into it. I'm sure I can find the proper place to tap/interrupt the existing squelch circuit with a bit of detective work/trial and error. 73, Mike WM4B
Re: [Repeater-Builder] MICOR Squelch clones
mwbese...@cox.net wrote: Thanks for that explanation... you're spot-on with your observation about how difficult it is to understand spoken-word chopped up Kendecom style! My system is on VHF, but exhibits exactly the behavior you describe and it's very difficult if not impossible to make any sense out of what is being said. Before you explanation, I could not rationalize why, but it makes good sense now. Eventually I'll try putting a Micor squelch into it. I'm sure I can find the proper place to tap/interrupt the existing squelch circuit with a bit of detective work/trial and error. Mike, On the Kendecom receiver, there is a discriminator output available. I don't have a manual handy to tell you the exact location on the board - sorry. Connect the MICOR squelch boards input to this pin, supply it with power, and use the logic output to drive your controllers COS input - observing proper logic polarity. It's as simple as that. Kevin
Re: [Repeater-Builder] MICOR Squelch clones
On Fri, Oct 23, 2009 at 9:42 AM, Kevin Custer wrote: mwbese...@cox. net mailto:mwbese...@cox.net wrote: Thanks for that explanation. .. you're spot-on with your observation about how difficult it is to understand spoken-word chopped up Kendecom style! My system is on VHF, but exhibits exactly the behavior you describe and it's very difficult if not impossible to make any sense out of what is being said. Before you explanation, I could not rationalize why, but it makes good sense now. Eventually I'll try putting a Micor squelch into it. I'm sure I can find the proper place to tap/interrupt the existing squelch circuit with a bit of detective work/trial and error. Mike, On the Kendecom receiver, there is a discriminator output available. I don't have a manual handy to tell you the exact location on the board - sorry. Connect the MICOR squelch boards input to this pin, supply it with power, and use the logic output to drive your controllers COS input - observing proper logic polarity. It's as simple as that. Kevin mailto:mwbese...@cox.net http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Kevin, http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Don't I have to disable the existing squelch circuit as well to prevent it from muting the RX? http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Mike http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg--
Re: [Repeater-Builder] MICOR Squelch clones
mwbese...@cox.net wrote: Mike, On the Kendecom receiver, there is a discriminator output available. I don't have a manual handy to tell you the exact location on the board - sorry. Connect the MICOR squelch boards input to this pin, supply it with power, and use the logic output to drive your controllers COS input - observing proper logic polarity. It's as simple as that. Kevin Kevin, http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Don't I have to disable the existing squelch circuit as well to prevent it from muting the RX? http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Mike http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Yes, that will be done when you connect the logic of the new squelch board to drive the controllers COS. Only the COS from the MICOR board should be connected to the controllers COS input, replacing the original COS logic from the receiver. Some controllers require a presence of voltage to validate activity on the channel, some require a ground. The Link-Comm MICOR squelch board (RLC-MOT) will supply either logic polarity, making installation easy. Kevin
Re: [Repeater-Builder] MICOR Squelch clones
On Fri, Oct 23, 2009 at 10:03 AM, Kevin Custer wrote: mwbese...@cox. net mailto:mwbese...@cox.net wrote: Mike, On the Kendecom receiver, there is a discriminator output available. I don't have a manual handy to tell you the exact location on the board - sorry. Connect the MICOR squelch boards input to this pin, supply it with power, and use the logic output to drive your controllers COS input - observing proper logic polarity. It's as simple as that. Kevin Kevin, http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Don't I have to disable the existing squelch circuit as well to prevent it from muting the RX? http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Mike http://groups.yahoo.com/start;_ylc=X3oDMTJuZDFvODVhBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNTM5Mg-- Yes, that will be done when you connect the logic of the new squelch board to drive the controllers COS. Only the COS from the MICOR board should be connected to the controllers COS input, replacing the original COS logic from the receiver. Some controllers require a presence of voltage to validate activity on the channel, some require a ground. The Link-Comm MICOR squelch board (RLC-MOT) will supply either logic polarity, making installation easy. Kevin http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- Luckily, I happen to have a manual copy with me today. I just took a quick glance... seems pretty straightforward. http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- Where'd I put the round-tuit? http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- 73, http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- Mike http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA-- WM4B http://groups.yahoo.com/start;_ylc=X3oDMTJuMzFkNWttBF9TAzk3MzU5NzE0BF9wAzMEZ3JwSWQDMTA0MTY4BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDbmNtb2QEc2xrA2dyb3VwczIEc3RpbWUDMTI1NjMwNjYzOA--
Re: [Repeater-Builder] MICOR Squelch clones
You guys have talked past each other slightly... Kevin, if he's not using straight discriminator audio into the controller, but picking off de-emph audio downstream from the Kendecom squelch gate, there will be times he has COS from the Micor module but no audio reaching the controller. Workarounds might include: (1) Leave the original squelch control open (2) Tap and buffer discriminator audio using a discreet or LM386 stage with R/C filter to provide unsquelched but de-emph audio for the controller (3) Use the COS signal from the Micor module to both provide COS to the controller and switch the Kendecom's audio gate I'd try for (3). 73, Paul, AE4KR - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Friday, October 23, 2009 8:03 AM Subject: Re: [Repeater-Builder] MICOR Squelch clones Kevin, Don't I have to disable the existing squelch circuit as well to prevent it from muting the RX? Mike Yes, that will be done when you connect the logic of the new squelch board to drive the controllers COS. Only the COS from the MICOR board should be connected to the controllers COS input, replacing the original COS logic from the receiver. Some controllers require a presence of voltage to validate activity on the channel, some require a ground. The Link-Comm MICOR squelch board (RLC-MOT) will supply either logic polarity, making installation easy. Kevin .
Re: [Repeater-Builder] MICOR Squelch clones
I disagree that an audio delay board negates the positive effect of a MICOR squelch. I have several repeaters where the controllers utilize an audio delay and MICOR squelch and none of them suffer any deficiencies because of the presence of the audio delay. In fact, it's nice to have a clean squelch tail after someone unkeys that exhibits a C/N that produces the longer tail. I think we need to get to the reasons why a multi-hysteresis squelch works and why it is desired. Then determine if there is a need for a real MICOR clone. I say real, because in my opinion, the microprocessor knock-offs that are available are not equivalents, none the less superior to the original analog design. Kevin Custer Skipp does have a really good point... I worked pretty hard to incorporate a micor chip onto a circuit board with an MX Com (whatever they are now) CTCSS chip, and audio gating, etc... a universal receiver interface board. Fabricated it, made it all work really nicely. Spent about a month of spare time breadboarding it, getting it right, layout out the board, fabricating... Then realized that the audio delay board in my controller made the micor chip a real moot point :) http://groups.yahoo.com/group/Repeater-Builder;_ylc=X3oDMTJjb3V2YnUwBF9TAzk3NDc2NTkwBGdycElkAzEwNDE2OARncnBzcElkAzE3MDUwNjMxMDgEc2VjA2Z0cgRzbGsDaHBmBHN0aW1lAzEyNTYyNTQzODg- http://docs.yahoo.com/info/terms/ mailto:repeater-builder-unsubscr...@yahoogroups.com?subject=unsubscribe
