Hi Guys,
Like the post says I need some help from some Quantar Gods. Here's what happening. I am working on a system for my local county to run GPS through their 2-ways. They have been contacted by a GPS company that will supply the modems and what not. My questions involve the infrastructure. Currently the county has 2 VHF Conventional repeaters that are connected via UHF Link(1 WR90 & 1 T800). So when repeater keys it also keys the other. Pretty basic. They are looking to upgrade the repeaters, I want to put in VHF Quantars, but the GPS guy is all about putting in TKR-750's. My questions are as follows.
1. I will program each Quantar with 2 channels. Channel 1 will be voice so I will have the channel setup as a repeater with about 1sec of hang time and TPL (hang time on only one repeater). Channel 2 will be programmed with the same freq's as in the first channel but setup as a base station and will be CSQ. The Quantar will have a Kantronics modem attached to it for the purposes of the data. Can the quantar be set so that when the Kantronics keys the repeater via external PTT the Quantar will automatically switch to channel 2 and when the transmission is finished it will revert back to channel 1? We are setting the system so that voice takes priority, is the quantar smart enough that when it is being keyed by the Kantronics that if it receives a signal with proper TPL that it will revert to channel 1? Am I on the right track or is there a better way to accomplish this?
2. Since each of the 2 Quantars will have a Kantronics modem attached what is the best way to link the two voice portions of the Quantars together?
Just to give you an overview of my skills and knowledge of Quantars, I have worked with Quantars before setting them up as stand alone VHF repeaters, as well as adding a UHF Link to the 50pin acc connector. So I have some experience changing the software setting for Rx Disc and stuff like that, but nothing major. I really want to use Motorola (particularly Quantars cause they kick ass) instead of Kenwood, even an MTR2000.
All help is much appreciated.
Let me know if you need any further info to help and I will get it for you ASAP.
Jamie
Quantar Surgeons Needed, HELP!
Moderator: Queue Moderator
Ok you have several problems here.
First is this a Public Safety system?
If so stop right now!
From reading the Kantronics web site I really dont see how you can do it.
It looks like the Katronics equipment needs its own dedicated channel.
If you must share your infrastructure you should look at something like CES products which will send the GPS data at the end of every transmission as well as polling. This simply interfaces to your existing radio via the accessory jack or through a microphone adaptor.
The dispatch centre has a dedicated radio which interfaces to the display PC.
First is this a Public Safety system?
If so stop right now!
From reading the Kantronics web site I really dont see how you can do it.
It looks like the Katronics equipment needs its own dedicated channel.
If you must share your infrastructure you should look at something like CES products which will send the GPS data at the end of every transmission as well as polling. This simply interfaces to your existing radio via the accessory jack or through a microphone adaptor.
The dispatch centre has a dedicated radio which interfaces to the display PC.
In addition to all other issues, while the Quantar can be programmed (within limits) for multiple channels, the parameter for "Base" or "Repeater" (which really means employing the internal controller or not) is set on a station basis, not a channel basis.
Compare 68-81085E35-R at p. 4-50 ("RF Configuration Screen") with id. at p. 4-32 ("Channel Information").
I therefore don't think that, at least via the Quantar's internal controller, you can program it to function as an in-cabinet repeater on one channel and as a base station on another.
You might be able to accomplish this using an external repeater controller with provisions for specifying output channel data on wireline access, such as a Zetron 38-Max, but without taking the time to sketch it out (which I have not done), I can't certify so.
Compare 68-81085E35-R at p. 4-50 ("RF Configuration Screen") with id. at p. 4-32 ("Channel Information").
I therefore don't think that, at least via the Quantar's internal controller, you can program it to function as an in-cabinet repeater on one channel and as a base station on another.
You might be able to accomplish this using an external repeater controller with provisions for specifying output channel data on wireline access, such as a Zetron 38-Max, but without taking the time to sketch it out (which I have not done), I can't certify so.
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Dan562
- Posts: 533
- Joined: Mon Aug 23, 2004 7:30 pm
- What radios do you own?: Kenwood, Yaesu, ICOM, Motorola
The SP now a standard option T1-2R is orderable through the /\/\ Factory Marketing Group as a FRU, I believe the option is priced at $1500.00 and has all of the hardware and software required except the separate standard T5589A ATAC Receivers, they have to be purchased in addition to the FRU Kits. BTW, these have been sold by the former Infrastructure SP Department to the State of Minnesota, City of San Diego and the FBI all being Public Safety Departments.
I think you would want to interface the modem tones into the Quantars General TX Data port which is available on the Telco 50-Pin connector and so is the Discriminator output. There's transistor Logic Low Outputs and one COR Logic Low that all come out on the Telco 50-Pin connector. All I / O wiring can be found in your Quantar Instruction Manual.
I think you should interface your computer and read the station's Hardware under the Service Mode to see if your Quantar has the Basic or Enhanced Wildcard function. If you have the Enhanced Wildcard, you'll need to script some tables and lines for these stations to do exactly what you're describing in your text.
Since F1 is Repeat and F2 is a Base Station, i.e. transmitting and receiving on Simplex, you would be required to purchase separate Astro-Tac T5589A Satellite Receivers and mounting each one under the Quantar Base Station / Repeaters. You would also be required to order the T/R Antenna Relay and DC cable assembly, the T/R Relay Common Port connects to the Duplexer's TX Input Port, the Antenna Relay Normally Closed Port connects to the T5589A ATAC Second Receiver and the Antenna Relay Normally Open Port connects to the Quantar's Transmitter Output Port.
You'll also be required to Enable the T/R Relay in the RSS/CPS. You'll be required to construct or purchase a RJ45 Telco cable to interface between the 50-Pin Telco connector and the RJ45 Jack on the rear of the T5589A ATAC providing the Wireline Muting function on transmit.
Oh Yeah, one other item on this T1-2R configuration, the Repeater mode has Priority!
I think you would want to interface the modem tones into the Quantars General TX Data port which is available on the Telco 50-Pin connector and so is the Discriminator output. There's transistor Logic Low Outputs and one COR Logic Low that all come out on the Telco 50-Pin connector. All I / O wiring can be found in your Quantar Instruction Manual.
I think you should interface your computer and read the station's Hardware under the Service Mode to see if your Quantar has the Basic or Enhanced Wildcard function. If you have the Enhanced Wildcard, you'll need to script some tables and lines for these stations to do exactly what you're describing in your text.
Since F1 is Repeat and F2 is a Base Station, i.e. transmitting and receiving on Simplex, you would be required to purchase separate Astro-Tac T5589A Satellite Receivers and mounting each one under the Quantar Base Station / Repeaters. You would also be required to order the T/R Antenna Relay and DC cable assembly, the T/R Relay Common Port connects to the Duplexer's TX Input Port, the Antenna Relay Normally Closed Port connects to the T5589A ATAC Second Receiver and the Antenna Relay Normally Open Port connects to the Quantar's Transmitter Output Port.
You'll also be required to Enable the T/R Relay in the RSS/CPS. You'll be required to construct or purchase a RJ45 Telco cable to interface between the 50-Pin Telco connector and the RJ45 Jack on the rear of the T5589A ATAC providing the Wireline Muting function on transmit.
Oh Yeah, one other item on this T1-2R configuration, the Repeater mode has Priority!
Last edited by Dan562 on Tue Oct 24, 2006 6:36 pm, edited 2 times in total.
Bruce1807 Posted: Tue Oct 24, 2006 4:52 pm Post subject:
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Ok you have several problems here.
First is this a Public Safety system?
This is not a public safety system, it's used for public works. This sounds like it could be complicated and expensive. Should I be listening to the GPS guy and installing a TKR-750 at each site? I will have to speak to the GPS contractor as he has said they have it working on motorola repeaters but he wasn't sure what kind. Would this be easier using an MTR2000?
Again what is the best way to have the modems attached to the repeaters and still have them linked together?
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Ok you have several problems here.
First is this a Public Safety system?
This is not a public safety system, it's used for public works. This sounds like it could be complicated and expensive. Should I be listening to the GPS guy and installing a TKR-750 at each site? I will have to speak to the GPS contractor as he has said they have it working on motorola repeaters but he wasn't sure what kind. Would this be easier using an MTR2000?
Again what is the best way to have the modems attached to the repeaters and still have them linked together?
You really should be able to do this project the way you want it with Quantars. The Quantar is the most flexible base Motorola makes - maybe the most capable that anybody makes - far more versatile than an MTR2000.
It appears that you want the following:
Voice traffic from mobiles and/or control stations is transmitted with PL and is repeated with PL. A UHF link ties two repeaters together so voice traffic from either is repeated through the other.
GPS data packets are transmitted by the mobiles without PL and are decoded at each Quantar by attached Kantronics modems but are not repeated or linked to the other site.
The Kantronics modem transmissions are transmitted outbound from the repeater without PL so that voice users with their mic on hook don't hear them.
If a Kantronics modem transmission is initiated through the repeater's transmitter but a voice transmission[with PL] arrives at the repeater's receiver during that time, you want voice to preempt the data.
Any additions or corrections?
It appears that you want the following:
Voice traffic from mobiles and/or control stations is transmitted with PL and is repeated with PL. A UHF link ties two repeaters together so voice traffic from either is repeated through the other.
GPS data packets are transmitted by the mobiles without PL and are decoded at each Quantar by attached Kantronics modems but are not repeated or linked to the other site.
The Kantronics modem transmissions are transmitted outbound from the repeater without PL so that voice users with their mic on hook don't hear them.
If a Kantronics modem transmission is initiated through the repeater's transmitter but a voice transmission[with PL] arrives at the repeater's receiver during that time, you want voice to preempt the data.
Any additions or corrections?
What are they proposing to install in the vehicles?
On their web site the only mobile units I see have their own radios?
The radio modems do not look for vehicular use.
This means that in each vehicle you will have two radios with the same RX/TX frequencies
The other issue is in your vehicles you will have two radios programmed the same just seems inefficient to me and bound to cause hassels.
On their web site the only mobile units I see have their own radios?
The radio modems do not look for vehicular use.
This means that in each vehicle you will have two radios with the same RX/TX frequencies
The other issue is in your vehicles you will have two radios programmed the same just seems inefficient to me and bound to cause hassels.
The Flexar was meant to be te most flexy wasn't it?xmo wrote:You really should be able to do this project the way you want it with Quantars. The Quantar is the most flexible base Motorola makes - maybe the most capable that anybody makes - far more versatile than an MTR2000.
No Quantar/Quantro series is extremly versitile and can be played around with many ways.
This still leaves issues with the UHF Link.Voice traffic from mobiles and/or control stations is transmitted with PL and is repeated with PL. A UHF link ties two repeaters together so voice traffic from either is repeated through the other
If a Kantronics modem transmission is initiated through the repeater's transmitter but a voice transmission[with PL] arrives at the repeater's receiver during that time, you want voice to preempt the data.
I dont have the RSS/CPS ( I know they still call it RSS but it is windows now at least) but you need a way to prioritize two wirelines.
You can do this with an 8 wire card and program console priority.
That would take care of that problem.
I have to admit I only get to play with intellirepeaters and use MTR2000 for anything conventional but did play a lot with non intelli trunked repeaters earlier, this is where the 8 wire audio comes in as we had centracom attached to each station through TBIMs, now we just use the ambassador to do its stuff.
I still think the whole process is a little messy and there are far better solutions to accomplish GPS tracking.
I assume you will also need dedicated land lines from each site to your dispatch center?
XMO - What you have is exactly what I'm looking for. I was hoping you'd see this post as I have got some help from you before.
Bruce1807 - The GPS company that is providing the kantronics modems makes a slight modification so that the vehicle only needs one radio and one modem. I'm not sure why we will need dedicated lines to the dispatch center. There will be two radios at the dispatch center. One for each repeater. These two radios will only receive GPS data. The GPS company has suggested this as they have it working in other areas. As far as mobiles in the vehicles, the GPS company tells me that as long as the radio is PC programmable with TPL we can make it work.
Bruce1807 - The GPS company that is providing the kantronics modems makes a slight modification so that the vehicle only needs one radio and one modem. I'm not sure why we will need dedicated lines to the dispatch center. There will be two radios at the dispatch center. One for each repeater. These two radios will only receive GPS data. The GPS company has suggested this as they have it working in other areas. As far as mobiles in the vehicles, the GPS company tells me that as long as the radio is PC programmable with TPL we can make it work.
You should not need modems at the site then unless they are going to regenerate the data.Vercomm wrote:XMO - What you have is exactly what I'm looking for. I was hoping you'd see this post as I have got some help from you before.
Bruce1807 - The GPS company that is providing the kantronics modems makes a slight modification so that the vehicle only needs one radio and one modem. I'm not sure why we will need dedicated lines to the dispatch center. There will be two radios at the dispatch center. One for each repeater. These two radios will only receive GPS data. The GPS company has suggested this as they have it working in other areas. As far as mobiles in the vehicles, the GPS company tells me that as long as the radio is PC programmable with TPL we can make it work.
With the use of Kantronics equipment and the 'store and forward' function at the repeater site, this sounds very much like an adaptation of APRS. In an amateur application, one or more digipeaters rebroadcast the packets thus allowing all the stations in a geography to see each other. The downside of repeating the packets is that every location transmission will use twice as much airtime as is actually necessary, thereby compounding the problems you may have with voice and data sharing the frequency.
If at all possible, it would be preferable to have a modem circuit from the repeater site to the dispatch point so that the digital traffic would not need to be repeated.
Either way, you should be able to configure a Quantar to meet your needs. For maximum capability you should order the station with 8-wire wireline, enhanced wildcard and MRTI enabled.
You should not need to have two channels programmed, you really only need to control which functions use PL and which do not. To set the station up, you would start by programming an access code table for the PL you want to use. On the channel information screen you will set the receiver qualifiers to CSQ. You should be able to connect the Kantronics to the MRTI port. It will recover the rx audio transmitted from the mobiles without PL. It will then retransmit the AFSK data through the MRTI port.
You will set the repeater activation to require carrier and PL. Voice transmissions from mobiles [with PL] will satisfy this and be repeated. You should configure the station's PTT priority settings so that the voice repeat has a higher priority than the link transmissions. Set the modem [MRTI tx] as the next lowest priority, i.e. R>W>M>D>L. That way a voice transmission from either repeater will preempt a modem transmission. The data widgets will then need to re-try, but they should see the channel busy and wait for inactivity before they do.
You can connect the link to the station's wirelines. The wireline connections plus COR and PTT are available on station connector 17.
To make everything work you will have to master wildcard programming. The action tables are basically like a simple programming language. Qualifiers are put in the state & conditions area of the table. When these qualifiers become true, the commands [actions] in the table are executed. You can also have additional inaction commands that are executed when the state / conditions return to false. In other words: if such & such happens [the states and/or conditions] then do so and so [actions]. Very powerful.
So that the modem will transmit without PL, you could create an action table that disables TX PL when the MRTI transmits. An alternative that might work better would be to create a table that turns TX PL on when repeater PTT becomes true and turns it off when it returns false [inaction]. You should create a similar table for the link PTT so that PL is on when needed and left off otherwise. That way, whenever the modem [MRTI port] transmits, TX PL will be off.
The wildcard programming can be a little quirky and not something you really can predict 100% from reading the manuals - so you will need to set up all the programming in the shop and test everything before you install the system.
You will also need to program an output to key the link transmitter when the station is receiving voice. The link would normally have no hang time in either direction so it can turn around immediately to follow response transmissions from one repeater to the other. You can put a hang time into the wildcard table that keys the station from the link so everything sounds the same regardless of whether it is a local repeated transmission or a linked one.
If you want, you could even have a short beep on linked transmissions so users can tell whether the station they are talking to is on the local or remote repeater.
Have fun with the project!
If at all possible, it would be preferable to have a modem circuit from the repeater site to the dispatch point so that the digital traffic would not need to be repeated.
Either way, you should be able to configure a Quantar to meet your needs. For maximum capability you should order the station with 8-wire wireline, enhanced wildcard and MRTI enabled.
You should not need to have two channels programmed, you really only need to control which functions use PL and which do not. To set the station up, you would start by programming an access code table for the PL you want to use. On the channel information screen you will set the receiver qualifiers to CSQ. You should be able to connect the Kantronics to the MRTI port. It will recover the rx audio transmitted from the mobiles without PL. It will then retransmit the AFSK data through the MRTI port.
You will set the repeater activation to require carrier and PL. Voice transmissions from mobiles [with PL] will satisfy this and be repeated. You should configure the station's PTT priority settings so that the voice repeat has a higher priority than the link transmissions. Set the modem [MRTI tx] as the next lowest priority, i.e. R>W>M>D>L. That way a voice transmission from either repeater will preempt a modem transmission. The data widgets will then need to re-try, but they should see the channel busy and wait for inactivity before they do.
You can connect the link to the station's wirelines. The wireline connections plus COR and PTT are available on station connector 17.
To make everything work you will have to master wildcard programming. The action tables are basically like a simple programming language. Qualifiers are put in the state & conditions area of the table. When these qualifiers become true, the commands [actions] in the table are executed. You can also have additional inaction commands that are executed when the state / conditions return to false. In other words: if such & such happens [the states and/or conditions] then do so and so [actions]. Very powerful.
So that the modem will transmit without PL, you could create an action table that disables TX PL when the MRTI transmits. An alternative that might work better would be to create a table that turns TX PL on when repeater PTT becomes true and turns it off when it returns false [inaction]. You should create a similar table for the link PTT so that PL is on when needed and left off otherwise. That way, whenever the modem [MRTI port] transmits, TX PL will be off.
The wildcard programming can be a little quirky and not something you really can predict 100% from reading the manuals - so you will need to set up all the programming in the shop and test everything before you install the system.
You will also need to program an output to key the link transmitter when the station is receiving voice. The link would normally have no hang time in either direction so it can turn around immediately to follow response transmissions from one repeater to the other. You can put a hang time into the wildcard table that keys the station from the link so everything sounds the same regardless of whether it is a local repeated transmission or a linked one.
If you want, you could even have a short beep on linked transmissions so users can tell whether the station they are talking to is on the local or remote repeater.
Have fun with the project!
Thanks xmo,
That was the kick start I needed! I may post more questions with regards to the wildcard tables and such.
I plan to use a Microwave Data Systems Transceiver for the link. MDS is supposed to have a unit that will do 4wire plus E&M. So I'll run my COS & PTT through the E&M leads. Beofre I get to carried away I've got to make sure that the MDS transceiver will do the 30mile hop that I require. Thanks again to all, I hope I can get everything figured out from here, but I will probably post more in this topic as things get more complex with the install.
Jamie
That was the kick start I needed! I may post more questions with regards to the wildcard tables and such.
I plan to use a Microwave Data Systems Transceiver for the link. MDS is supposed to have a unit that will do 4wire plus E&M. So I'll run my COS & PTT through the E&M leads. Beofre I get to carried away I've got to make sure that the MDS transceiver will do the 30mile hop that I require. Thanks again to all, I hope I can get everything figured out from here, but I will probably post more in this topic as things get more complex with the install.
Jamie
Well I'm several weeks into this project and hit a major road block. I cannot get a square wave out of the Quantar for the GPS data.
I am having a ton of trouble with the GPS porject I am building with the Quantars. The CDM mobiles are working good, but I can't get good data (square wave) out of the Quantar.
The wildcard tables are working okay, but I have injected audio into the MRTI Mic port, and the Aux Tx port on the 50pin. I have been working on it for the past week now and the GPS guys are here to commission the system. I was wondering if you could help any.
I have all of the filters disabled in the channel info screen. The only thing that is working properly is the discriminator audio.
Perhaps I need to use the 6809 interface for the data, but I'm not sure how to fully enable that port and there is a pin for Tx Data + and Tx data -.
I don't mind paying for technical help if that's whats required.
Hopefully you get this today, I would love to get any kind of help.
If you wish to call me and shout any ideas my number is 780-853-3799
Thanks,
Jamie
I am having a ton of trouble with the GPS porject I am building with the Quantars. The CDM mobiles are working good, but I can't get good data (square wave) out of the Quantar.
The wildcard tables are working okay, but I have injected audio into the MRTI Mic port, and the Aux Tx port on the 50pin. I have been working on it for the past week now and the GPS guys are here to commission the system. I was wondering if you could help any.
I have all of the filters disabled in the channel info screen. The only thing that is working properly is the discriminator audio.
Perhaps I need to use the 6809 interface for the data, but I'm not sure how to fully enable that port and there is a pin for Tx Data + and Tx data -.
I don't mind paying for technical help if that's whats required.
Hopefully you get this today, I would love to get any kind of help.
If you wish to call me and shout any ideas my number is 780-853-3799
Thanks,
Jamie
I thought from previous posts that your system was using Kantronics interfaces for the data. Normally, these convert the logic level data to audio tones called AFSK or MSK [Audio Frequency Shift Keying or Minimum Shift Keying] - in other words - in addition to containing a microprocessor based data controller [packet controller] the Kantronics box also contains a modem.
The audio tones are transported across the radio channel. In this case the LAST thing you want is to adjust your radios to transmit square waves because that means the tones are in clip which causes distortion and lowers the reliability of the data transmission.
You want to adjust the Kantronics [modem] tone level into your radios[mobiles, base or repeaters] so that the transmitted tone deviation is about 60% of the maximum for your system [+/- 3 KHz for 5 KHz systems]
60% of full deviation will be just below the level where the transmitter's clipper starts to act and is the best compromize between mimimum distortion and maximum signal to noise ratio.
The audio tones are transported across the radio channel. In this case the LAST thing you want is to adjust your radios to transmit square waves because that means the tones are in clip which causes distortion and lowers the reliability of the data transmission.
You want to adjust the Kantronics [modem] tone level into your radios[mobiles, base or repeaters] so that the transmitted tone deviation is about 60% of the maximum for your system [+/- 3 KHz for 5 KHz systems]
60% of full deviation will be just below the level where the transmitter's clipper starts to act and is the best compromize between mimimum distortion and maximum signal to noise ratio.
Well, after living in a 10' by 10' shelter for 3days and making a rush trip to another service shop I have concluded the following:
1. The Kantronics modem outputs a very nice looking square wave from its Tx audio port.
2. The first thing that a Quantar receiver does after it demodulates the signal is runs it through a A > D codec. Since we are putting in a square wave, somehow the codec ruins it enough that when the data is retransmitted, the other modems do not recognize it as a valid packet.
Somehow I need to get a analogue wave form into the quantar so that the codec will not screw the waveform up.
I'm no expert on the Kantronics 9612plus modem so i'm not even sure if I can use it to retrasmit the packet data in a sine wave for the quantar.
I just happenrd to have an MTR2000 and got the modem working on it, just have to figure out the link.
I'd like to use the Quantars, but if I can't get them to modulate a square wave using the Tx audio of the Kantronics unit, then I'm gonna have to find some MTR's.
Thanks Guys,
Jamie
P.S, Since we are using the 9600packet does that make sense why the Quantar wouldn't work
1. The Kantronics modem outputs a very nice looking square wave from its Tx audio port.
2. The first thing that a Quantar receiver does after it demodulates the signal is runs it through a A > D codec. Since we are putting in a square wave, somehow the codec ruins it enough that when the data is retransmitted, the other modems do not recognize it as a valid packet.
Somehow I need to get a analogue wave form into the quantar so that the codec will not screw the waveform up.
I'm no expert on the Kantronics 9612plus modem so i'm not even sure if I can use it to retrasmit the packet data in a sine wave for the quantar.
I just happenrd to have an MTR2000 and got the modem working on it, just have to figure out the link.
I'd like to use the Quantars, but if I can't get them to modulate a square wave using the Tx audio of the Kantronics unit, then I'm gonna have to find some MTR's.
Thanks Guys,
Jamie
P.S, Since we are using the 9600packet does that make sense why the Quantar wouldn't work
Last edited by Vercomm on Sun Apr 22, 2007 11:51 am, edited 1 time in total.
Apparently you are configuring the system to use 9600 baud packet rather than 1200 baud. I don't think I would do that.
For a GPS location system, the small size of the data payloads compared to the channel access overhead probably means there is little real throughput advantage to the use of 9600.
The problem is that your radios are not designed for 9600 data. Some amateur transceivers are designed for this and hams have developed modifications for a number of other radios but the problem I see is that your application isn't ham.
These radios are not type accepted for this application. There are many potential problems that come to mind such as spurious emissions, occupied bandwidth and violation of license emission designation.
None of that matters in the amateur world where there is plenty of spectrum and experimentation is encouraged but around here I would be concerned that a co-channel or adjacent channel user would report the operation to the authorities.
I recommend you consider staying with 1200 baud AFSK. It is easy to implement, works well, and is compatible with your radios without any modifications.
For a GPS location system, the small size of the data payloads compared to the channel access overhead probably means there is little real throughput advantage to the use of 9600.
The problem is that your radios are not designed for 9600 data. Some amateur transceivers are designed for this and hams have developed modifications for a number of other radios but the problem I see is that your application isn't ham.
These radios are not type accepted for this application. There are many potential problems that come to mind such as spurious emissions, occupied bandwidth and violation of license emission designation.
None of that matters in the amateur world where there is plenty of spectrum and experimentation is encouraged but around here I would be concerned that a co-channel or adjacent channel user would report the operation to the authorities.
I recommend you consider staying with 1200 baud AFSK. It is easy to implement, works well, and is compatible with your radios without any modifications.
Hi xmo,
Thanks for the input. I have no control over what the system uses, as far as 1200AFSK vs 9600Packet. I believe we are using 4800 baud. That decision was made by the GPS provider, he gets Kantronics to modify all of the modems he buys and then provides them to the user. He does nothing with the radio system, that where I come in. I'll ask him what we could do as far as the 1200AFSK. I'm also gonna check with Industry Canada with respect to our license and the data.
Just an Fyi, using the MTR2000 and the CDM's has produced very reliable data transmission. We are running 100% currently.
Like I say, I will check in more about using AFSK vs the packets, but for now I'm going to temp wire in the MTR because I have a council meeting on Tuesday and they want to see some graders on the computer.
Thanks Again xmo, I appreciate the input.
PS, Since The modem is using 9600, does that make sense to you that the Quantar wouldn't work?
Thanks for the input. I have no control over what the system uses, as far as 1200AFSK vs 9600Packet. I believe we are using 4800 baud. That decision was made by the GPS provider, he gets Kantronics to modify all of the modems he buys and then provides them to the user. He does nothing with the radio system, that where I come in. I'll ask him what we could do as far as the 1200AFSK. I'm also gonna check with Industry Canada with respect to our license and the data.
Just an Fyi, using the MTR2000 and the CDM's has produced very reliable data transmission. We are running 100% currently.
Like I say, I will check in more about using AFSK vs the packets, but for now I'm going to temp wire in the MTR because I have a council meeting on Tuesday and they want to see some graders on the computer.
Thanks Again xmo, I appreciate the input.
PS, Since The modem is using 9600, does that make sense to you that the Quantar wouldn't work?
Yeah. In the SCADA systems I've worked with, specialised data bases and radios are generally required for reliable 9600 operation. I'm not familiar with the Quantar (everything I've done has been with Trio data bases, or Tait T800, and old rockbound Philips FM815 stations), but if it does have an internal A->D->A process while repeating, that will cause trouble at high data rates.
1200 or 2400 would work fine. 4800 will be marginal, but I'd avoid 9600.
Roughly how many GPS-equipped radios will you have on the channel, and are they polled, or do they automatically transmit their position automatically, and how often?
1200 or 2400 would work fine. 4800 will be marginal, but I'd avoid 9600.
Roughly how many GPS-equipped radios will you have on the channel, and are they polled, or do they automatically transmit their position automatically, and how often?