Need help brainstorming...how to make lemonade out of lemons

[aaknitt]

Hello everyone,

I moved to a new state over a year ago and finally found the time to get involved with the local fire department. I was on a department in Wisconsin before I moved and we had a very decent VHF hi-band communications system. On my new department the radio communications for the entire county seem to be whacked beyond belief. From what I can tell so far there are four PSAPs in the county (I'll call them A, B, and C, and D), and there are four different VHF hi frequencies that fire departments are toned out on. However, there isn't one frequency per PSAP...it's a mix and match nightmare.

There are no VHF repeaters...everything is on simplex except for some remote dispatch links on UHF (see below). The frequency that my department uses is also used by another department adjacent to us and another department one township away, which is a full time department with a fairly heavy call volume. The full time department uses Dispatch center A.

The town I live in is a small little burg of 700 people. We're far enough away from our dispatch center (dispatch center B) that they can't reliably tone us out from there. Instead, they have a crossband repeater set up at our fire station. The dispatch center transmits on UHF and it gets repeated to VHF hi, where our pagers hear it. In order for us to talk to dispatch, we talk on our VHF frequency but transmit a PL tone. The PL tone activates the link the other way and the dispatch center hears us on UHF. Our normal traffic (traffic not intended for dispatch) is carrier squelch. Here are problems #1 and #2: #1 - when we're not talking to dispatch, dispatch doesn't hear us, and so may talk over one of our units unknowingly. In the same way, our dispatch doesn't hear the traffic of the other departments on the same frequency, and so may talk over them unknowingly. I've heard this happen. #2 - the cross band repeater is sitting on the desk in the radio room, and everyone has been trained that you pick up the top microphone to talk to dispatch (the UHF radio), and the bottom microphone to talk to our units (the VHF radio). Problem is that when someone sitting at that desk picks up the top mic to talk to dispatch, it only keys the top radio, so our units in the field don't hear the traffic. No one knew this was even happening until I saw the setup and questioned it. They swore up and down that when you talked on the top mic both dispatch and our units heard the traffic until I demonstrated that that wasn't the case (actually even after I showed them I had a hard time convincing them).

Since there is so much traffic on the VHF frequency we use (mostly from the full-time department), the other two departments (the full time and other volunteer) have added PL decode to their radios to "solve" the problem. In my opinion that's a very bad solution. While multiple PLs on a single frequency might be fine for taxi cabs and delivery trucks, I don't think it's appropriate in a public safety application. Too much risk of someone unintentionally talking over the top of someone else (which I've heard happen numerous times) at a very bad moment.

Now my department wants to add PL decode to our radios so we don't have to listen to the traffic from the full time department. I'm trying to think of an alternative that's not going to cost a ton of money, but that assures us safety (through lack of interference potential). I've created coverage plots using RadioMobile and confirmed my fears...the range of our units will be severely degraded when the other dispatch centers are talking, but we won't know they're talking if we are using PL decode.

Another problem with going to PL decode: I've been told that dispatch doesn't want to hear traffic that's not intended for them, so we don't want to bring up the cross band link unless we're talking to them. So, if we leave the link on PL tone A, but use PL tone B for our normal traffic, when one of our units goes to talk to dispatch the rest of our units won't hear that transmission because they're decoding PL B, not PL A!

I can't think of a good solution (to the problem of not wanting to listen to the full time department's heavy traffic), other than registering for a second frequency to use for our normal operations, and leave things the way they are for talking to dispatch. I've been told it costs $2500 to modify our FCC license, which is prohibitively expensive. That number seems high to me though...any insight on that figure?

What we really need is a unified county radio system. I'm not in a position to make that happen, though, so I have to work with what I have. The level of radio knowledge on my department is nill, so I need to think of something that's easy to understand, implement, and fund. Any ideas or thoughts would be appreciated. I'm somewhat afraid that I'm so new on the department that no one will listen to me and a bad situation will become worse (by going to full PL), so I need to figure out something simple and relatively soon. Sorry for the really long post!

Thanks in advance,

Andy

[nmfire10]

Everything you stated is right on the money. It's a mess and from what they are planning, it will get exponentially worse.

About the only 'free' thing you can do is use V-TAC channels for you on scene portable-to-portable work. You won't need a license for it and you'll probably be the only ones on it. It will at least give you fireground radio traffic that isn't being stepped on. Unfortunately, to talk to units not on scene or to dispatch, you would still need to use the pending-disaster channel. There isn't much I can think of that will make this problem go away for cheap. The best way to handle it is licensing another frequency and changing from the nightmare net to your own. That will cost money.

[aaknitt]

I was thinking something along the same lines. We are part of a mutual aid organization that holds a statewide license for a bunch of fireground frequencies, and I think I'm going to try to convince the powers that be to start utilizing them as standard procedure. That will take some doing, since right how they're convinced (incorrectly) that they're only allowed to use those channels on mutual aid calls. I hadn't thought of the V-TAC channels, and honestly I'm only vaguely familiar with them...I believe they're a relatively new development aren't they? I'll look into that, as that might be a good alternative, since as you mentioned, they're probably not being used at all. Do you know where I might find more info on the rules regarding these channels?

Other suggestions are welcome! I was hoping there was a silver bullet out there I hadn't thought of.

Thanks,

Andy

[CuriousGeorge]

You can't legally use VTAC for routine communications within your department. They are for inter-agency use. This is per the FCC rules for those channels.

Using your statewide channels may or may not be permissible -- depends on the specifics of the agreements that cover those channels.

As far as the cost to modify your license, how many sites and channels are you looking at? Assuming you stay VHF Highband, simplex, with a base station at your headquarters and everyone else is using mobiles or portables (i.e., no other base stations), I would think you would only have to pay APCO $210 for the frequency coordination and probably qualify for a fee exemption from the FCC.

http://www.apcointl.org/frequency/docum ... e1-03a.pdf

Assuming you have non-crystal radios, I don't see where the other $2000+ is coming from. We've been going through this for our department - our big cost is that we need to replace our UHF Minitor II pagers with something VHF highband - but we paid under $600 to coordinate the repeater pair at one site and nothing to file it. No extra cost for the mobiles, portables or control stations.

[aaknitt]

Thanks for the good information. I thought the $2500 figure seemed out of whack. I was told that it cost $2500 any time we touched the license. It may have cost them that last time they changed it because they were putting up a tower, etc. But just to add a frequency I thought, as you said, that it would just be the cost of coordination. I'll look into it further.

Thanks,

Andy