1. #1
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    Default 800 radio problems

    I was talking with some of the local police and they were saying that there are problems with trying to talk from inside a building to the outside and vice-versa. They were saying that you will need to go to a talk a round channel and use like the old portables. The main problem they said was reaching the repeater and geting back to the inside crews. They felt it was important that the fire company know this problem exist. Has anyone else had problems or heard of anything like this. We currently are running 80oHZ radios and have not had a problem.
    Last edited by asst102; 08-15-2005 at 11:06 AM. Reason: spelling
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    It has nothing to do with 800Mhz really. It is simply a matter of SYSTEM design. If you are operating through a repeater on a radio tower, you need to be within range of that radio tower for it to work. The portable might be able to reach the tower from outside the building just fine. However, inside the building you have all kinds of obstacles. You lose a lot of you signal to the walls and roof of the building and therefore it is not going to go as far. In their case, it is not making it to the radio tower. It does however make out of the building far enough to talk on direct from inside to units outside in close proximity.

    This is not the fault of the radio, the user, or the frequency it's on. This simply a matter of the radio's infrastructure not being built to have in-building talkback. Yell and scream at the ******* who designed the radio system and the *******s who penny pinched it. It's a common problem. Having complete in-building talkback is really expensive and for some reason, the budget people think that having a radio that only works half the time is acceptable.

    Now, in the fire service you should always be doing your interior operations on direct anyway. You never want to rely on a repeater or a trunking talkgroup when you are inside a burning building. There is nothing to get in the way or malfunction if you are on direct.
    Even the burger-flippers at McDonald's probably have some McWackers.

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    I agree with nmfire. We have the same issues here. Our city is about 55 square miles and for the majority of the city we don't have any issues. We do run into problems inside some of our buildings with basements and in a part of our city that has a 'dead zone'. I don't know if you guys do fire inspections or prefire plans, but when your inside some of your bigger buildings or ones with basements you might try doing a radio check.

    Also, I agree with nmfire that fireground ops should be on a direct channel. Unfortunately, ours are not. We have 10 ops channel...all of which go through the repeater.

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    If you have a repeater, then you have a direct channel. It's a matter of programming the portable radios to do it at that point.
    Even the burger-flippers at McDonald's probably have some McWackers.

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    I am a radio man in my side job. For 800 MHz all other things being equal, you will need a lot more repeater sites to get the same coverage. Typically what happens is the big "M" will lowball the bid in order to get the job and put in the minimum number of sites to meet the terms of the contract. Then the users come back and say the coverage sucks, and the big "M" will say sure we can fill in those holes, we will just need to put another site here and here and here $$$$$

    It is a real racket they've got going there and it keeps repeating over and over and over again.

    Birken

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    Prior to any trunking system being installed the "user" will approve the coverage map provided by the vendor. If the "user" approves the coverage map then they are the one who are at fault for not having proper coverage. When we went to a trunked system we looked at every angle and possible dead spot. With this in mind we came out with a system that has no problems. We have built in back-ups and have not experienced any difficulties. As for the big "M" they have the market in our area. Another jurisdiction tried the big "G" and could not even talk face-to-face wheather it was repeated or not. Entire system was removed. Same for another large metopolitan department, system was removed and trashed. That department went back to a duplex system with simplex system as a back-up.

    Try not to blame the vendor. They are given the dollar amount to work with and that is all they can do.
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    I believe existing NFPA 1221 or changes that are being proposed mandate (reccommend?) that fireground channels be direct channels.

    Motorola builds to spec. Blaming them or GE or MA/Com or any of the others is a cop out. Get serious bid specs, get a good purchase agreement, talk about coverage requirements and not just "theoritical" get real performance based testing included in your system acceptance and you will better off.

    I don't like the idea of these systems being sold to politicians. No one gives the the techies the power to make the best decisions. Here in Colorado, there is little coverage mapping done of the state 800mhz system after a site is built. Pretty sad to spend 300,000 and not know what it does.

    With large new buildings, require in building repeaters (pay for by the developer) if you think that it will fly.

    Don't the system (pay for it) until YOUR coverage demands are met.

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    there is a great ariticle in this months http://www.jems.com/firerescue/ by Nick Brunacini.
    IACOJ both divisions and PROUD OF IT !
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    http://www.firehouse.com/forums/show...60#post1137060post 115

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    We're having these same problems here in Austin.

    Here's another twist. One of our recent post 9-11 hi rise projects consisted of thicker concrete construction etc... Our radios don't transmit out of the building.

    The builders installed an internal antenna which allows for transmissions in and out of the building. They have private hand sets we have to pick up in the fire control room.

    During our walk threw with the engineer he explained that fire frequencies where not operable on the system. Sounded like it was possible but the financiers didn't want to fund it.

    Not as familiar with this system as some posting.

    I thought this was odd.

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    We have the same problem with our 800 system. A vendor from the big M said with coverage studies and his word that if we did not have 100% coverage he would do what it took to make it work. Forgetting to add that it would be at our cost. Never worked never will. We will be replacing the 800 soon with all that money thrown away.

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    In building coverage is not easy to obtain in a high rise. It is VERY expensive in a building like that since you have such a large area to cover. You have to run leaky coax from the roof to the basement, power deviders, bi-directional amplifiers, filtering, etc.

    When the dealer says 100% coverage, they are usually talking about either MOBILE coverage or portables standing outside. No dealer in their right mind would ever tell someone they'd have 100% portable in building coverage because it is hardly practical.
    Even the burger-flippers at McDonald's probably have some McWackers.

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    This was mobile coverage outside. Portables are almost useless on our 800 unless you can see the tower. It is clearer and sounds great if your close enough to the repeater to throw a rock at it. Our terrain is so hilly that it blocks the signals much like buildings do in town. We have been stuck with this system but will be replacing it with a vhf system that works.

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    Maybe my comments about the big M were a little exaggerated, like the Chief says it might just be their vendors. Used to be they owned a lot of shops but lately they have spun those off to be independent. Nevertheless they do a lot of bait and switch and if it isn't in writing it never happened. Make sure you have an ironclad contract even buying a pickup truck.

    That being said the comment about not working unless you can see the tower. What is happening here is the 800 system is basically the same as a cell phone. Think of how well a cell phone works and then ask if you want your fire radio to work that well. Now think if you want to be responsible for installing and maintaining what basically amounts to a cell phone network, yourself. For some cities that are flat and have lots of public agencies on the system it makes sense. However they must be sure that garbage trucks, school buses, etc. get bumped off the system in favor of police and fire, that was an issue with a lot of the early systems, and that there is enough system capacity that this doesn't happen very often. And the solution to the buildings is as mentioned to make the building owner responsible for radio retransmission inside the building. This can get really expensive, I have installed a few bidirectional systems now and every step of the way costs.

    Nevertheless I still think VHF-high band is the way to go for public safety. It is a short enough wavelength that portables work, yet long enough that trees and hills are not always a killer. Redundancy is key, we have two repeaters manually switched that cover our 92 square mile district and a third that also covers it, as well the surrounding fire districts. The entire west half of the county is covered by three repeaters on high mountains and their average age is probably 20 years or so. I wonder if these 800 systems will still be around in 20 years.

    Birken

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    We had simillar problems with our 800mhz system.

    Most of the problems have been fixed. ( took quite awhile though)

    The biggest improvement has been the addition of repeaters on every Engine and Ladder.

    Now at a "Box" call with 3 Engines 3 Ladders and a Heavy Rescue we end up with 7 repeaters onscene. ( Not including any close towers )

    With a large building we can position truck around the building to get the best coverage.

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    My volunteer departments is part of a East County 800Mhz system (1 of 2 in the County). Since its inception about 14 years ago the system has performed far better than anyone could have hoped. In that time frame we have been "off line" unscheduled on no more than 12-14 occasions with the longest period of time being 2 hours. During that time we switched to our back-up channels on the other county 800Mhz system and went on as usual.

    In the past 30 days we have upgraded from the Smart Net system to the Smart Zone system which increases our range greatly and offers the ability to switch to a more appropriate repeater site automatically (No manual changes) based upon the signal strength from the repeater sites it is sensing. This is all based upon the location of the specific radio being "keyed up", not all of them since all of them may not be in the same location. All in all, been a damn fine system and I wouldn't want to switch back to anything else.

    Just a thought.
    Last edited by STATION2; 08-16-2005 at 06:21 PM.
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    nmfire,

    In building coverage is not easy to obtain in a high rise. It is VERY expensive in a building like that since you have such a large area to cover. You have to run leaky coax from the roof to the basement, power deviders, bi-directional amplifiers, filtering, etc.

    When the dealer says 100% coverage, they are usually talking about either MOBILE coverage or portables standing outside. No dealer in their right mind would ever tell someone they'd have 100% portable in building coverage because it is hardly practical
    I think this was a response to my post about the internal hi rise antenna.

    I'm going to get some more info on this one. I'd like to get your take on it.



    Our system is working out OK in normal use.

    This system was designed to operate when the S##t hits the fan. We have had issues with overloading the system during big events with unusually high traffic volumes. This basically puts us back to the good old days.

    We have had issues with combining police, fire, and ems on this system.

    The high volume of police traffic was overloading the system.

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    WE have problems with our less than 1 year old 800 system. Whether they will ever be fixed or not I can't say. What I can say is our old VHF radios, with all of their faults, gave better coverage than these 800 radios do.

    My comment on vendors and the manufacturer is simple. If they sold a city a system they knew wouldn't work, regardless of whether it was what the city specified or not, I believe it is fraud at worst and at the very least a horrible business practice. There is no law that says the customer is always right. If the system they spec won't work and you know it going in then tell them and don't bid it. If you do your ethics are in question. It certainly does not build customer satisfaction to have a vendor or a manufacturer install something they know won't work and then tell the purchasing agency they need to install hundreds of thousands of dollars more in upgrades to make it work.

    FyredUp

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    Well it happened, We had a automatic fire alarm on Tuesday, Bldg was on generator power and lights were flickering on and off. Bulilding security was there and we entered the building threw a shop area to access the main office to reset alarm. I tried to call dispatch, when my capt. came over and said all that came from my transmission was beeps and a few words. We are now educating our members of the problem and looking for a solution. Luckly it was a false alarm and was not an emergency.
    ASST.102
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    That is why interior crews need to be on a simplex channel!! Case and point!
    Even the burger-flippers at McDonald's probably have some McWackers.

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