UHF Mobile repeater setup

[maurycofire]

Good afternoon,

I work for a local FD in the middle TN area. Just as a little background we cover 620 Sq miles and have 5 tower sites on an analog UHF system (yes, we are behind). With that being said we have many radio dead spots where are portables will not get out. We have had some sites additions quoted, but at well over 100K each, that is a work in progress. Our local radio shop is good, but we find we can do most things MUCH cheaper in house.

We have looked into the idea of adding some mobile repeaters to some of our front line trucks and we have been quoted over $3,000 per truck. Does anyone have any guidance on how we can go about doing this our-self? Just as a side note- we are in the progress of moving from Motorola HT1250s to the Kenwood NX300 and NX800s as well as some NX3000s etc.

Thanks in advance.

 

[IAmSixNine]

Do the 5 sites give you good coverage when the repeaters are active and the portables can RX ok? If so another option might be a voting type of RX system for the repeaters. But your suggestion is good as well if configured properly.

 

[RFI-EMI-GUY]

Good afternoon,

I work for a local FD in the middle TN area. Just as a little background we cover 620 Sq miles and have 5 tower sites on an analog UHF system (yes, we are behind). With that being said we have many radio dead spots where are portables will not get out. We have had some sites additions quoted, but at well over 100K each, that is a work in progress. Our local radio shop is good, but we find we can do most things MUCH cheaper in house.

We have looked into the idea of adding some mobile repeaters to some of our front line trucks and we have been quoted over $3,000 per truck. Does anyone have any guidance on how we can go about doing this our-self? Just as a side note- we are in the progress of moving from Motorola HT1250s to the Kenwood NX300 and NX800s as well as some NX3000s etc.

Thanks in advance.

When your system was moved to FCC mandated narrow band operations a few years back you lost 6 dB of performance which is noticeable. More if the shop did not properly adjust the bandwidth of the repeaters.

Adding receiver sites might help somewhat but the coverage would be to be studied to see where receivers could be placed. If your system is presently simulcast and uses voters this might be an easy improvement. If not, the whole system might need a redesign.

Vehicular repeaters are generally cross band systems where in your case with mobiles on UHF the portables would be on VHF. If you are buying dual band portables this may work for you to have a VHF fire ground channel. If you want in band UHF to UHF repeaters, you need to install bandpass reject filters in the vehicle so that the repeaters will work properly. This gets expensive but can be done. Your vehicular repeater frequency needs to be ideally 5 MHz or further from both the TX and RX of your mobile radio. So if your mobiles are 453/458 MHz, your repeater would need to be on 461 MHz or so.

Pyramid makes the SVR200U model vehicular repeater. Contacting their engineering department would be a good start.

 

[maurycofire]

I should have added this, but we have 5 sites only 3 are Tx and Rx, the other 2 are receive only sites. It does work, but not very well. As long as we use mobile radios we can usually get out okay but not where I want us to be.

I can say this, I am the one who does all of our radio programming, installing, etc. and your reply was a bit over my head. I am going to try and do some more research and "dumb down" the VHF and UHF mobile repeater process. Something we are having the biggest issue with is the fact that our local shop only wants to do work on Digital systems and we do not currently have the funding to move over to digital. They have much larger contracts and they put us aside (somewhat understandably) and it becomes and issue. Hints as to why I want to try and do some of this myself. Anyways, I digress.

Do you think that $3,000 is overly expensive to install a mobile repeater? If so, I will do it myself if possible. We do not have dual band portables so this may cause some issues. We have looked into the Kenwood Macros system, but have not secured the funds for a full upgrade.

Thank you for the replies and I hope to find out some more on this soon.

Thanks again.

 

[maurycofire]

Sorry guys, one last question...

We have talked about adding some additional sites, we have the means in house to do the work for the most part, but our local shop made the hint that our system was "maxed" out. Is this even possible? I was under the impression we could add as many sites as we wanted.

Thanks again

 

[RFI-EMI-GUY]

Your local shop sounds like a "peach", not having time to deal with you because your system is "analog", telling you your system is "maxed out" and not explaining what that even means. Is there another shop, next county over maybe?

Maxed out at three sites? Not any hardware I know about. Maybe in simucast site separation. Or your system might be beyond its useful life. Probably is. That happens. But analog is not dead, only wounded by FCC/Motorola conspiracy to narrow band everything. How to fix?

Five site analog simulcast? That is an option. You will have to rip everything out and replace. Hope the towers and shelters are in good shape.

Five site "Digital" simulcast? That will get you 9 dB improvement over where you are today just in the "digital" part. It can be APCO P25 or DMR. DMR would be cheaper, you can still have analog interoperability and talk around. You will be told you HAVE to go P25 for FCC reasons. That is not true at all. Yes P25 is required to get federal funding for radios that honestly, the match won't cover the price of going P25.

As far as $3K per vehicular repeater? Probably so. To be compliant with FCC you will need to buy new Pyramid repeaters, plus install, plus filters for in band UHF-UHF use. But then you still have that old system that is "Maxed out" whatever the heck that means.

Is this a DIY project? For me maybe.

 

[TampaTyron]

$3k per vehicle is reasonable. Your system sounds interesting. I am a DMR guy so I would recommend a multisite DMR system. Since you are going to Kenwood equipment, it should be just as easy to go to amultisite NXDN system. Stay away from p25 unless a grant or another agency is paying for it or you are required to by regulation. TT

 

[N5XPM]

So many unknowns here it is difficult to start. What would help is an FCC license callsign so we can see what the current system is. Also, if the current repeaters are over 10 years old and the antennas and coax are as well, those probably need some work before wasting time on subscriber units. Two or three new mobiles and portables might help in the testing process to ensure the user end is fully operational as well. Not as fun as buying new radios, but might be money better spent first. Once the existing infrastructure is in top shape, it might be possible to optimize the whole system.

 

[maurycofire]

Thanks for all of your help! We will continue to try and work with our local shop and the information all of you have provided will better help me when we meet. Thanks again!

 

[dwgelle]

We used to use these from Pyramid SVR-200's not sure on cost anymore though. Can find used ones on ebay. And can set up to where if you have more than one of these on the scene the last one to activate will be the main unit.
Vehicular Repeater Products - Pyramid Communications

 

[kg4ere]

I do not mean to sound crass, but if you cannot understand how a simple cross band repeat works then perhaps it is better left to a qualified shop. Looks like WPWG336 covers Maury County Fire. I am also slightly suspicious at the intentions. Are you sure you are not wanting to create a vehicle repeater for yourself?

 

[maurycofire]

What you consider to be a "simple" cross band repeater may not be some simple to someone who does not do this for a living and could care less about it. That is why I came here... I am just trying to help our local fire department. Why would I want an in car repeater for myself? Why would I not want to save money and do the install myself? The reason I came to this forum is decide if it is a project I want to tackle or allow the shop to do it. So your suspicions can be settled, if I wanted an in car repeater for personal use (or why ever you think I need one) I would have one installed.

Anyways, thank you to all of those who had positive input and were able to not worry about my intentions.

 

[mmckenna]

I do not mean to sound crass, but if you cannot understand how a simple cross band repeat works then perhaps it is better left to a qualified shop. Looks like WPWG336 covers Maury County Fire. I am also slightly suspicious at the intentions. Are you sure you are not wanting to create a vehicle repeater for yourself?

It may not be a "simple cross band repeat".

Depending on how it needs to be set up, it may be an "in band" system, which has some challenges.

MauryCoFire….
A couple of questions,
Which band is your primary dispatch channels on? I see the license shows some VHF and some UHF.
What about your hand held radios?

If you use a single band portable and all your dispatch is on the same band, then you'd have an in-band repeater. Those can be tricky to set up since you need some pretty good filtering and antenna separation for it to work well. Getting the filters tuned correctly is usually outside the capability of most. It requires some equipment that you might not have.

If your portables are multiband, and you can set up the repeater to be a "cross band" repeater, as mentioned above, it's a bit simpler to do. Usually no filtering is required and you just need some separation between the antennas. It needs to be different bands, though. So UHF portables to a UHF mobile repeater, then VHF out from the truck.

It's not impossible to do this, but it can be very difficult to do it correctly. When lives are on the line, it's very different than the hobby world. Asking this sort of question on a hobby website is going to get you all kinds of answers.

I'd recommend finding out from the shop exactly what they propose to build for you. $3K might be reasonable depending on the solution. None of us can really tell you what the best solution is without having some more info.

Also, don't be afraid to check around with other radio shops. You might find different shops will have different approaches and different costs.

 

[buddrousa]

I understand all about saving your department money. But radios are life safety devices and if you do it your self and have no formal training will your city, county or department back you if something goes bad wrong the system fails and there is a loss of life. You need to ask and get the backing or you could be left out on a limb all by yourself. Good luck with your project and protect yourself also.

 

[N5XPM]

Thanks to KG4ERE for the FCC license link. The license only authorizes analog narrowband emissions for all frequencies and no mobile (vehicular) vehicular repeaters. Legally enabling the digital modes and the MO3 for the mobile repeater will consume most of the budget before any mobile repeaters are installed. Licensing may appear boring, but not doing it correctly projects a sloppy attitude, as well as financial and operational risks. Hydro-testing SCBA can be skipped, fire vehicle equipment maintenance, etc. as well to save money. This project will go better if you get some experienced communications help. Paying for professionals in radio communications system design will be the best long term approach.

 

[maurycofire]

Thanks for all of the replies. Our primary dispatch frequency is 453.07500. I do want it to be known that if this is something that a shop need to do, we will spend the money to have it done correctly. I do think it is important to mention that I (we) did not realize there was more to putting in a mobile repeater than simply putting it in, installing some antennas, and programming. All of our current radios, portables and mobiles, are single band UHF.

Our current system has very poor, if no coverage inside homes and buildings. We are just looking to improve this and maybe cover some of our dead spots. We do cover a large area and have looked into adding some additional sites but at 100k plus for each site this is not in our budget.

I will reach out to the shop and see what they have to offer. It may take a while for me to get a response, but in the end they built the system and know the most about it. I also want to add, we do not "hate" out local shop and they do seem to do good work, but again we are not a top priority for them at this time. We do see that they have a lot more and bigger projects that are time sensitive so they do favor those jobs more.

Lastly, there is not another shop locally that deals in Kenwood (that we can find) and we do not plan to go to the TACN Motorola system at this time. We find Motorola equipment to be much more costly and we have a surplus of great Kenwood equipment that we have purchased from other local department that have moved to the 800MHZ TACN system.

 

[mmckenna]

Thanks for all of the replies. Our primary dispatch frequency is 453.07500…..All of our current radios, portables and mobiles, are single band UHF.

OK, so yeah, you'll need an inband system to do it with the equipment you have now. That will require licensing changes. You'll need a mobile repeater input frequency well above 453MHz to get the spacing for the filters to work correctly. Antennas will need some good separation, also, to prevent desense of the system when it's working. A good shop can do this for you.

You could save some money by going to a split system (VHF/UHF), but then you'd be carrying portable radios that would -only- be able to talk to your dispatch through the mobile repeaters. Doesn't do you much good to go that route.

There are also some "wireless mic" type systems that would give you a few hundred foot range, basically it's a microphone that connects back to the mobile wirelessly. They won't be rated for what your guys would need inside a structure fire, but they'd give you a bit additional reach back to the truck for medical calls, etc. They are more designed for a police officer getting out of the car during a traffic stop. Cheaper solution, but I doubt it's what you'd be looking for.

I will reach out to the shop and see what they have to offer. It may take a while for me to get a response, but in the end they built the system and know the most about it. I also want to add, we do not "hate" out local shop and they do seem to do good work, but again we are not a top priority for them at this time. We do see that they have a lot more and bigger projects that are time sensitive so they do favor those jobs more.

Yep, and until you show up with money in hand, it's going to be a low priority for them. They are a business and they need to make a profit. Profit is not a four letter word. Working with small agencies can be hard, it takes a lot of work to support them, and often the profit margins are small.

Lastly, there is not another shop locally that deals in Kenwood (that we can find) and we do not plan to go to the TACN Motorola system at this time. We find Motorola equipment to be much more costly and we have a surplus of great Kenwood equipment that we have purchased from other local department that have moved to the 800MHZ TACN system.

Yeah, Motorola tends to price themselves out of the small agency market.

Have you tried this Kenwood dealer locator tool? COMMUNICATIONS Dealer Locator - KENWOOD USA That might help you find another dealer local to you.

 

[WB9YBM]

"Does anyone have any guidance on how we can go about doing this our-self? "

If this were the ham radio community the DIY approach would be a piece of cake. Unfortunately the FCC does not really look favorably on the "home-made" approach on the commercial side (probably because if something goes wrong lawsuits would be flying all over the place). The best thing I could suggest might be to take one of these mobile repeaters (or "mobile extenders" as they're sometimes referred to) from the police service--prices should be a bit more reasonable on the used/surplus market--and have a radio shop (or somebody with a commercial FCC license) put them on your frequency.

 

[buddrousa]

Again look at my other post if the county attorney will not sign off on this project and you do not have training and experience and equipment then the risk is all on the installer for life or property. We live in a sue happy world and the installer will be the scapegoat.

 

[kayn1n32008]

If your system coverage is inadequate, hire a consultant to model existing coverage, and find the ideal locations to either redeploy your existing infrastructure and/or add infrastructure to provide the coverage you need. Maybe deploying mobile repeaters can solve your issue. There are far too many unknown variables to give you a divinities answer as to what direction to go.

You really need to bring in some independent expertise to assess what exists, and propose solutions.

If you want to stay analogue, make it a requirementin any future RFP. Your department is the ones spending the money, you drive the project.

The radio company that told you your existing system is ‘maxed out’ needs to be avoided like COVID-19.