Needing help for County radio coverage

[tcash158]

We have a large County and have had trouble covering it for years we recently went to a repeater from a different tower location and there are still 2 areas of our County 1 north and 1 south that have trouble with their pagers going off and talking back to dispatch. This is all on a vhf hight 154 range and we have been told they can put in repeaters in those locations but we would we have to change channels for PL reasons depending on what area we go to. This was so the repeaters wont squeal and give feedback on the radios. In all of this no one in the County wants to switch channels depending on where we go and we want County wide coverage for a large County and we want to stay on the vhf high so we dont have to buy all new radios and pagers. Can anyone help me with this of what to do? We all have Motorola radios and pagers to.

[The Pager Geek]

Sounds like you need simulcast transmitters with voted receivers.

Very common.

tpg

[kb9suy]

2 repeater talk outs one north and one south simulcasted.

[john9912]

A lot of variables and unknowns. I would suggest getting proposals from local radio vendors or a contract a consultant. Have computer generated radio propagation studies done. Using propagation software to see if a new tower location will improve coverage is easier than actually erecting a new tower. There are limitations of software but it should provide you with a good idea. Depending on size of the county, terrain, and building construction, you may find that there is no one site that will effectively provide the coverage you are looking for.

Suggestions.... different location, higher antenna, different type of antenna, higher tower, increased power output, multiple locations w/simulcast transmitters + voting receivers, secondary notification services (like text messaging), combinations of the suggestions, or maybe even ALL of the suggestions. Check with the local ham radio operators. Do they have any repeaters that cover the whole county? There are probably other suggestions that might help, but it is almost 4am here and can't think of anything else right now

Good luck

[tcash158]

What kind of cost is there for 3 sites and will any of the portables or mobiles in the County have to changed? They are on a repeater now so can you just use the same frequecies input and output and the same PL and put up the 3 sights and the voters?

[psapengineer]

Check out these two links:

Our system is described here: http://www.kittcom.org/geninfo.htm

See this for more information: http://www.simulcastsolutions.com/case-studies.htm

Truly, for wide area coverage you need some very experienced technical engineering and support.

[john9912]

Still WAY too many unknowns. There are many qualified people here but, I don't think anyone here can tell provide you with the information you are looking for without taking an in depth look at the specifics in your county. A local professional engineer or radio vendor can look at your system in depth and can recommend a system that will work for you.

What kind of cost is there for 3 sites

Could range from a few thousand dollars to well over a two hundred thousand dollars per site. Do you own land at the perspective sites? Are there a towers there? Tower shelters? How tall do the towers need to be to provide the coverage you are looking for. How can the sites be linked to each other? Tie Line? Microwave? x-band links? IP? Will the sites have a clear microwave path between each other? Backup batteries? Generators? Recurring monthly fees? Rent payments? etc. etc etc. Too many questions, too many things to look at.

will any of the portables or mobiles in the County have to changed? They are on a repeater now so can you just use the same frequecies input and output and the same PL and put up the 3 sights and the voters?

Again WAY too many unknowns to give you a good answer. You will need to check with your frequency coordinator. Your repeater is usually licensed at one site only. It cannot be moved or simulcast without getting new frequency coordination for the new sites. Example... You may find out the frequency can not be relicensed in the north part of town because that transmitter will be too close to an adjacent channel or co-channel user in another county.

John Liguori
All Technical Services, LLC
Franklin, NJ

[psapengineer]

It's expensive but worth it. Now, assuming that a design is even possible...............

Yes, there are too many unknown's to give a good answer, but for a starting ball park, it's north of probably 85K/site and maybe south of 160K/site, plus 35k at the dispatch center. It can be done cheaper but it wouldn't have the reliability needed by public safety. The second channel is incrementally way cheaper................

This assumes that all sites can see each other or see dispatch, the towers can support dishes, and the buildings and generators can support the new load.

See this for cost justification comments; it tells why we changed to voted simulcast:

http://urgentcomm.com/mag/radio_jps_com ... ions_case/

Regards, Bob

[firefighter13669]

We have the same problem.

The solution they came up with for us is to stick 8 repeaters on the same feq with diffrent pl tones.This is a mess and does not work well at all.The also have a rebroadcast system over the same repeater.I myself would go with a voting system .

You can thank our local Moto dealer for our current mess.

[Jim202]

Before you say it is a mess, you need to explain that position in more detail.

The state of New Hampshire for years had the fish cops on a common pair of RF
channels at multiple repeater sites to cover the state. They selected the site
from the mobile via different CTCSS tones. The main dispatch center could
select which repeater to use in talking to the mobiles.

This single channel pair and multi site system works very well for a low traffic
system. However if you expect to see any high volume traffic, then a better
solution is needed.

Jim

We have the same problem.

The solution they came up with for us is to stick 8 repeaters on the same feq with diffrent pl tones.This is a mess and does not work well at all.The also have a rebroadcast system over the same repeater.I myself would go with a voting system .

You can thank our local Moto dealer for our current mess.

[firefighter13669]

The System I am talking about works like this

Their are 8 Fire Repeaters some repeaters we put up because depts complained about their pagers not going off.

The repeaters all have a long hang time and all the you could have 2 depts that boarder each other how ever one uses rpt 1 and one uses rpt 6 .With the long hang time agencies dont know enough to wait so you you loose half of the transmissions.Depts choose wich ever rpt they want to use its not based on location as it should.Some of the rpts have dupluxer problems when dispatch uses the you get about 10 mins of static and other noice at the end of transmissions.

They are not using any RF links ect here