System Questions

This forum is for discussions regarding System Infrastructure and Related Equipment. This includes but is not limited to repeaters, base stations, consoles, voters, Voice over IP, system design and implementation, and other related topics.

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BigTex1136
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System Questions

Post by BigTex1136 »

OK so our county FD and SO we have 3 repeater sites in the county and they all TX and RE the same with each having there own TX PL tone and the same RE PL Tone for all 3. They are linked to dispatch but then who ever is dispatching has to change to the right repeater so we can hear them. It really does not work at all because dispatch really just stays on the main site unless we ask them to use the repeater where we are. That's what I know but I really want to find out how hard it would be to link all 3 repeaters. The main thing is so when dispatch talks they talk on all 3 at the same time. Its be nice to link the whole system but I know that will cost big time right??? How is this done?

We have newer Moto Repeaters VHF MSF5000 and not sure what they are using for the link to dispatch.

Our local M dealer is a total joke and scam. Our fire district no longer buys crap off them. Never the less they gave the county a bid to over haul the system with a simulcast system from all 3 but they wanted way to much money it just did not add up to me for what we were getting. So my thought is to get some info here and talk with our county com guys and see if we can just like dispatch only to all 3. In the field we will still have to use whatever repeater we are closer too but we will hear dispatch on all 3. Thanks for the help guys
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Bill_G
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Re: System Questions

Post by Bill_G »

Go to Simulcast Solutions and read their case studies. It is not cheap, but done right, simulcast sounds great. I prefer analog myself, but IP based systems can be beaten into submission. Generate the PL at the central site and ship it out with the voice audio envelope. Don't try to gen PL at each site. You'll always get a growl in the overlap. Dial the deviation from each station within hundredths of a volt of each other, and you'll get seamless coverage with no interference overlap zones. The Convex audio bridge with it's multi-turn pots is a great product for achieving that kind of precision. Use the same base stations at each location so you get the same audio response curve. Use a microwave to transport between sites. Don't try to mix telco and microwave.

OR

You can get a JPS SNV-12 voter, and use it's channel steering feature (aka Poor Man's Multi-Cast) to direct the repeater output to the last voted receiver. It doesn't work perfect, but it does help land dispatch on the right site if dispatch is coming in on the console input. If dispatch is using a base station, and participates like the other users, xmit steering won't work as intended.
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BigTex1136
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Re: System Questions

Post by BigTex1136 »

Thanks I will check it out. The problem we have is Dispatch switching to the right repeater from there console so guys like me in the far south of the county can't hear the main repeater. Case in point yester day we had an MVA dispatch toned out 4 fire districts to go but only used county main repeater. We all missed the call down here. Anyways I will do some reading and see how things go I guess. Just another idea for the tool box
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kb4mdz
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Re: System Questions

Post by kb4mdz »

Sounds like some operational issues here, as well as the technical issues; if the dispatchers have some sort of issue with switching to the correct repeater maybe they don't know how, or they're too lazy/unconcerned/don't understand how important it is.

BTW, do NOT expect a technical solution to ever overcome a human problem. Repeat this at least daily until you have the problem solved.

BTW, what kind of console do they use?

Transmitter steering could be one solution. In fact, there is probably a range of solutions, depending on complexity, cost, heartburn, etc.
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Bill_G
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Re: System Questions

Post by Bill_G »

We have coastal counties with difficult terrain and thick forests that try to cover their primary service areas with just three sites doing the same trick - different access PL, but a common output PL - and dispatch finds it impossible to use the correct site. I tried putting very low level audible tones at different freqs on them, but a lot of people are tone deaf and couldn't tell the difference. I tried beep counts at the end of each transmission (beep for site 1 chan 1, beep beep for site 2 chan 2, etc), but that drove people nuts. And they still got it wrong. There is no easy solution except to simulcast. And then you get to battle the county commissioners for the money. Figure $25-50K per channel per site minimum, not including building a site if necessary. If you simulcast more than one channel per site for different agencies, your per channel costs go down because all of the infrastructure can be reused. You only need one gps reference oscillator per site. you only need one channel bank per site. You only need one microwave. Etc. So, if you can get fire and sheriff to work together, split the budget, and you both come out ahead. That takes long range planning. Around here, counties need four to six sites to cover everywhere.
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escomm
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Re: System Questions

Post by escomm »

I have an easy solution. Inject a second unique PL on the output from each repeater using a TS64 and decode it at the base to drive an LED or something. Then dispatch knows what repeater is active and can easily steer to that channel.
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BigTex1136
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Re: System Questions

Post by BigTex1136 »

Dispatch is the problem both lazy and they dont care. Not what console they are using but ill check. They can see clear as day what repeater we are using they just dont care enough to move there finger up to push that repeater. So and fd would split the bill as its the same problem for them and county communications is done by fd. Thanks for all the input now I need to go gather more equipment info and start talking and I hope to get the approval to start getting some bids going.
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kb4mdz
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Re: System Questions

Post by kb4mdz »

Might need yourself a big ol' can o' whoopass to deliver on the dispatchers, as well as a technical solution. Repeat what I said above about human problems.

I can make hardass statements, tho I admit I'm not the one who needs to or gets to open that can;

How about these two that I learned while I was working in the Quality profession:
1) Management gets what it wants. Even if it doesn't like what it gets.
2) Approx. 80% of problems in an organization are what is called 'Management Controllable'. Management is in charge of allocating resources (time, money, training, motivation, whatever) to achieve the objectives.

If management doesn't care that they have lazy uncaring dispatchers, that's what they'll have. Someone, or several someones need what we call here in The South call a 'Come To Jesus Meeting': You will behave as if you care, you will respond as if peoples' lives depend on you and if you don't, management gets to put a boot in your ass. If that doesn't work, you can find another position more suited to your apathy.
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kb4mdz
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Re: System Questions

Post by kb4mdz »

Sorry, I've been working with an ex-Marine; Boot in the Ass is always acceptable management speak in the Marines. But I see by looking around on the county's website, there is a board of directors, etc.
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Re: System Questions

Post by srvigalot »

I would just set up a perminant multi-select at the console so they broadcast on all 3 at the same time.
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BigTex1136
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Re: System Questions

Post by BigTex1136 »

The permanent multi select is what I was thinking. Really would like dispatch to come across on all the repeater sites. The real issue is personal is just lazy and this should fix that. How hard is the permanent multi-select to do? Just a matter of reprogram the console? What about the repeater sites? Since they will all be TX dispatcher only is there anything that needs to be done at each site?
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Jim202
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Re: System Questions

Post by Jim202 »

BigTex1136 wrote:The permanent multi select is what I was thinking. Really would like dispatch to come across on all the repeater sites. The real issue is personal is just lazy and this should fix that. How hard is the permanent multi-select to do? Just a matter of reprogram the console? What about the repeater sites? Since they will all be TX dispatcher only is there anything that needs to be done at each site?



The major problem with keying up all 3 transmitters at the same time is they are not set up for simulcast. Your going to need to find a way to have ultra stable frequency control for the transmitters. This helps to prevent hearing a beat note when your in the no capture area between the overlap of the transmitters.

The audio going to each of the transmitters need to be timed very closely so you don't get audio distortion caused by the different distances to each of the transmitters from the dispatch center. If the control of the transmitters is via a telephone line, you could end up with the phone company screwing you up when they move cable connections around when they do repairs.

The biggest problem is finding the radio techs that have the skill and test equipment to pull off the adjustments needed for this simulcast package that your going to need. This assumes that this is the route you choose to take. Expect to install a special GPS timing receiver at each of the transmitter sites. The transmitters will need to be able to accept an external timing reference.

Good luck on your efforts to solving the problem.

Jim
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Bill_G
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Re: System Questions

Post by Bill_G »

I agree with Jim. Multi-selecting will be a disaster. If simulcast is what is required, put it out to bid, and get it done.

Your only other choice is multicasting - a common rx input with a different tx output at each site with a central voter and the means to link all the sites together. Then it's on the users to select the best channel so they can hear the repeater where they are working. Not a perfect solution either, but it's cheaper than simulcast with most of the advantages.
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kb4mdz
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Re: System Questions

Post by kb4mdz »

BigTex; Still sounds like you have a people problem at dispatch.

Maybe grab someone from Dispatch Management and get them down in your neck of the woods for a day of driving around and let them experience what the problem is from your side. Missed calls, trouble getting Dispatch to hear you, whatever. They may be hearing what you're saying, but still filtering it thru their experience, and thus not recognizing the real problem.

I'll bet dollars to donuts that upgrading a system to one that the dispatchers have to think even MORE to use, will be a failure.

As always, expect lots of whining "Why do we have to do it this way?", "I like the old way better." etc.

Correct responses, in different words: "The old way didn't work." "Yesterday is over."
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BigTex1136
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Re: System Questions

Post by BigTex1136 »

Thanks all for the replies. In our neck of the woods we are the red headed step kids of the county being we are so far away and on the edge of our county and next to 3 other counties. So getting anyone from Admin, dispatch, or even just the fleet mech. takes an act of congress lol. Never the less just wanted to grab some ideas and next time I am up in Admin I wanted to float ideas out there and see what I can learn at the same time and maybe get them to look outside the box and away from our not so local not so nice and not so friendly M dealer who sells there stuff like its made of GOLD. Anyways thanks again guys for all the input
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BigTex1136
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Re: System Questions

Post by BigTex1136 »

Thanks all for the replies. In our neck of the woods we are the red headed step kids of the county being we are so far away and on the edge of our county and next to 3 other counties. So getting anyone from Admin, dispatch, or even just the fleet mech. takes an act of congress lol. Never the less just wanted to grab some ideas and next time I am up in Admin I wanted to float ideas out there and see what I can learn at the same time and maybe get them to look outside the box and away from our not so local not so nice and not so friendly M dealer who sells there stuff like its made of GOLD. Anyways thanks again guys for all the input
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abbylind
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Re: System Questions

Post by abbylind »

D
Dont tell me but it must be "Sanchez Fe County" :lol: .....good luck

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A: hello yes its in the radio thanks
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BigTex1136
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Re: System Questions

Post by BigTex1136 »

LoL yeah its them.
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