We recently implemented a channel marker to our conventional 450 radio system. We are using the MGE consoles that link to the CEB and back to the Quantro repeater that has a voted receive.
Here is the situation; the channel marker is set to broadcast every 10 seconds and if the dispatcher or a unit in the field is keyed the channel marker will not broadcast until the repeater is de-keyed.
The problem is that once the channel marker starts to key, during the two seconds that it takes for it to key and broadcast it is uninterruptable. If a radio in the field keys the dispatcher will hear the transmission of the field unit coupled with the channel marker tone and the unit in the field will hear the channel marker and not the field units transmission.
Does anyone know of a solution that will fix this problem? Has anyone had this problem what did you do to remedy it? Is there an aftermarket product that is available that we in place?
Thanks in advance
Motojoe1
Channel Marker Problem
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Re: Channel Marker Problem
Could you be more specific with regards to your existing configuration?motojoe1 wrote:We are using the MGE consoles that link to the CEB and back to the Quantro repeater that has a voted receive.
How does the CEB connect to the repeater? Through a comparator? If so, what kind of comparator and how does the CEB interface to it? (Console priority, other...)
tpg
Experienced Provider of Useless Information
Re: Channel Marker Problem
I'd like to know why there is a channel marker every 10 seconds? And what is it doing for two seconds out of every ten? A long beep can get to be annoying. All you need is a bip very low level every 30 seconds, or so, that has no priority - that it can be over ridden by normal traffic, definitely not heard in dispatch, and not heard in the cars until the mic is off hook. I'd be hating this thing about 3 minutes after it got turned on.
Re: Channel Marker Problem
The default interval for the Gold Elite channel marker is ten seconds but the interval can be programmed with the CDM for anywhere from 1 to 155.
What it is doing for two seconds is probably based on the channel keyup and dekey timing values hard coded into the BIM for TRC.
The fact that the field units can't override the tone [console initiated transmission] would be normal assuming the system is set up as a typical public safety system with 4-wire control of the repeater and wireline priority for the console [default WRL]. That allows the dispatcher to override a stuck mike and still be heard by the users or to interrupt a long winded user to make an important announcement.
It would be normal for the dispatcher to be able to hear incoming audio during the console initiated transmit - so it appears that the system is operating the way it is designed.
You could certainly minimize the distraction by changing the channel marker interval. An alternative would be to have the Quantro repeater generate the marker. To do that you could add a wildcard icon on the console screen. That icon would be labled "Channel Marker".
In addition to the console wildcard programming the Quantro would need some magic wildcard programming. The wildcard tone state for "channel marker on" could set a flag in the Quantro wildcard programming. A timer [for the marker interval] would start and upon expiration activate another timer[for the beep duration] during which time the RF tone function would send a beep over the air as a channel marker tone. Another wildcard command could also send a corresponding tone back down the wireline to the console. This sequence would execute over and over until the console operator sent the wildcard tone corresponding to "channel marker off".
Based on past experience with Quantar wildcard programming - I believe that this could be done - but I don't have time right now to test it out in the lab - so you'll either have to do it yourself or pay a radio shop programming wizzard to do it for you.
BTW - regarding "... not heard in the cars until the mic is off hook..." - that could also be done with the Quantro programming to disable TX PL before the beep gets sent. You would probably also want to suspend the beeps whenever the console was actually keyed down or whenever the station receive is active. With a voted system, both are basically the same to the Quantro since the comparator handles the console priority and all station transmit [console or repeat] is wireline PTT initiated - so the wildcard programming only needs to suspend the beeps during wireline PTT.
All that is possible with wildcard programming - but this level of complexity would need a Quantar/Quantro guru!
What it is doing for two seconds is probably based on the channel keyup and dekey timing values hard coded into the BIM for TRC.
The fact that the field units can't override the tone [console initiated transmission] would be normal assuming the system is set up as a typical public safety system with 4-wire control of the repeater and wireline priority for the console [default WRL]. That allows the dispatcher to override a stuck mike and still be heard by the users or to interrupt a long winded user to make an important announcement.
It would be normal for the dispatcher to be able to hear incoming audio during the console initiated transmit - so it appears that the system is operating the way it is designed.
You could certainly minimize the distraction by changing the channel marker interval. An alternative would be to have the Quantro repeater generate the marker. To do that you could add a wildcard icon on the console screen. That icon would be labled "Channel Marker".
In addition to the console wildcard programming the Quantro would need some magic wildcard programming. The wildcard tone state for "channel marker on" could set a flag in the Quantro wildcard programming. A timer [for the marker interval] would start and upon expiration activate another timer[for the beep duration] during which time the RF tone function would send a beep over the air as a channel marker tone. Another wildcard command could also send a corresponding tone back down the wireline to the console. This sequence would execute over and over until the console operator sent the wildcard tone corresponding to "channel marker off".
Based on past experience with Quantar wildcard programming - I believe that this could be done - but I don't have time right now to test it out in the lab - so you'll either have to do it yourself or pay a radio shop programming wizzard to do it for you.
BTW - regarding "... not heard in the cars until the mic is off hook..." - that could also be done with the Quantro programming to disable TX PL before the beep gets sent. You would probably also want to suspend the beeps whenever the console was actually keyed down or whenever the station receive is active. With a voted system, both are basically the same to the Quantro since the comparator handles the console priority and all station transmit [console or repeat] is wireline PTT initiated - so the wildcard programming only needs to suspend the beeps during wireline PTT.
All that is possible with wildcard programming - but this level of complexity would need a Quantar/Quantro guru!
Re: Channel Marker Problem
Thanks to everyone for your input!
To be more specific about the system; our consoles are wired to the BIM witch leave the CEB through a through our cloud MW or Fiber converted back to 4wire into the Astrotac Comparator. From the comparator to the to via 4wire back into the cloud (MW or Fiber) to the Quantro. Additionally there is a backup Quantro that paralleled in after the comparator that is switched. Consoles do have priority through the comparator. I think that about sums it up with respect to the system configuration. Hope that provides some insight TPG.
As to the frequency of the channel marker interval that is something that is programmable via the MGE. The 10 second interval was something that was required by the department. If the interval is too short, it gets really annoying. If the interval is too long it defeats the purpose of using the channel marker.
I am looking for the solution that will provide the low level beep that has no priority. I would like to be heard by both the units in the field and dispatch. I want to the dispatcher to be aware that channel marker is active so they don’t inadvertently leave it on!
XMO
Thanks for the insight I think you hit it right on. I am going to look into the wildcard programming solution.
Thanks,
Joe
To be more specific about the system; our consoles are wired to the BIM witch leave the CEB through a through our cloud MW or Fiber converted back to 4wire into the Astrotac Comparator. From the comparator to the to via 4wire back into the cloud (MW or Fiber) to the Quantro. Additionally there is a backup Quantro that paralleled in after the comparator that is switched. Consoles do have priority through the comparator. I think that about sums it up with respect to the system configuration. Hope that provides some insight TPG.
As to the frequency of the channel marker interval that is something that is programmable via the MGE. The 10 second interval was something that was required by the department. If the interval is too short, it gets really annoying. If the interval is too long it defeats the purpose of using the channel marker.
I am looking for the solution that will provide the low level beep that has no priority. I would like to be heard by both the units in the field and dispatch. I want to the dispatcher to be aware that channel marker is active so they don’t inadvertently leave it on!
XMO
Thanks for the insight I think you hit it right on. I am going to look into the wildcard programming solution.
Thanks,
Joe
Re: Channel Marker Problem
Good luck with all of that, I've never heard of it being done, and I'd be interested to learn the results myself!
Re: Channel Marker Problem
In simpler shared channel, non-trunking, conventional systems there is a need to mark a channel busy so that officers that turn on their radio during an incident do not interrupt. They hear the beep and know not to say anything - use the phone or use another channel. Trunking systems can assign a tac talkgroup, and move traffic there.
Re: Channel Marker Problem
In his first post, motojoe1 said it is a voted system. If the system used Spectra-TAC or Digitac, a solution based on wildcard tone remote control and Quantro programming would be possible.
In his second post he mentioned Astrotac. That implies digital or mixed mode operation and a DIU + ACIM interface to the CEB. That's a different can of worms.
In that case I would be inclined to program an onscreen "Channel Marker" icon to operate an Aux-I/O relay and have that control a simple hardware based beep generator connected to the transmit audio input of the MRTI port on the DIU. The DIU audio would be given lower priority than repeat or console audio so that transmissions from radios in the field or from the dispatcher would override the marker beeps and always be heard by everyone.
In his second post he mentioned Astrotac. That implies digital or mixed mode operation and a DIU + ACIM interface to the CEB. That's a different can of worms.
In that case I would be inclined to program an onscreen "Channel Marker" icon to operate an Aux-I/O relay and have that control a simple hardware based beep generator connected to the transmit audio input of the MRTI port on the DIU. The DIU audio would be given lower priority than repeat or console audio so that transmissions from radios in the field or from the dispatcher would override the marker beeps and always be heard by everyone.