Narrowbanding / Refarming Help...

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radio230
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Joined: Tue Dec 12, 2006 12:14 am

Narrowbanding / Refarming Help...

Post by radio230 »

First of all, Happy Thanksgiving to everyone!!!

Now down to buisness. I have just recently taken over as the radio equipment coordinator for my local fire department. We are located in Illinois and currently using the Statewide P25 Starcom21 radio system for all primary radio communications, however we use our old analog VHF repeater system in wideband mode for paging, which we share with 3 other nearby departments. The paging channel is patched into the Starcom21 system to provide radio information to firefighters responding that only have pagers. We also still maintain all our previous VHF equipment to use as a backup in case this new fancy radio system goes down completely (it has happened a couple times) not to mention that two of our trucks potentially could get called to respond mutual aid quite a long distance through MABAS. I have a decent working knowledge of radio equipment and what is required to come into complaince with the new narrowbanding rules, but have a few questions.

First, we plan on using the same frequencies we currently use, just changing them over to narrowband mode. All our radio equipment is capable of this except a couple MT1000 portables that we will take out of service. My question is can we change individual radios over a couple at a time and still have them work properly. Money is an issue so having techs come out to both our engine houses and reprogram ever piece of radio equipment at once is difficult. What I want to do is starting with the repeater itself, have radios reprogrammed systematically. Basically can a radio set for wideband hear and talk with a radio set for narrowband and vice versa. And we (and the otehr departments) carry Minitor V pagers, do they have a programming setting for wideband or narrowband.

Any advice anyone can offer would be greatly appreciated :)
Dan Collins
Telecommunicator - Cahokia, IL Police Department
Firefighter - Cahokia Volunteer Fire Department
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The Pager Geek
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Re: Narrowbanding / Refarming Help...

Post by The Pager Geek »

After just living through this myself... here's what I can tell you...

Here's the short answers:
A Narrowband transmitter can be heard by a Wideband receiver
A Wideband transmitter will be over-deviated and distorted, possibly not even heard to a narrowband receiver.

Minitor V pagers have a tick-box to change from Wideband to narrowband, although a pager set as wideband will still funtion with a narrowband transmitter. Even Minitor 2,3, and 4 do...

The EASIEST way to do this is either double programming or zones.

Step 1: Program the new narrowband configuration into the existing subscriber equipment
Step 2: On a scheduled day, reprogram the repeater for the new narrowband equipment, then have the subscribers change to the "new" channel with narrowband
Step 3: Reprogram the subscribers to take out the wideband channels.

That's a high-level overview in simplest terms.

Hope that helps,
tpg
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escomm
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Re: Narrowbanding / Refarming Help...

Post by escomm »

OP: Research your FCC license. If your authorization is granted under Part 22, then you are in all likelihood exempt from narrowbanding and can continue operating wideband for the foreseeable future. If it's granted under Part 90 then disregard my post.
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The Pager Geek
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Re: Narrowbanding / Refarming Help...

Post by The Pager Geek »

escomm wrote:OP: Research your FCC license. If your authorization is granted under Part 22, then you are in all likelihood exempt from narrowbanding and can continue operating wideband for the foreseeable future. If it's granted under Part 90 then disregard my post.
Good call...

If this is his license http://wireless2.fcc.gov/UlsApp/UlsSear ... ey=1288502 then it falls under Part 90. BUT, OP will need to modify the license for narrowband.

tpg
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radio230
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Re: Narrowbanding / Refarming Help...

Post by radio230 »

Pager Geek, that is indeed our current license and the freqs we need in narrowband. Thank you and escomm for your advice. I can see now this is going to be more difficult that I hoped. I have another question though.

I know we need to change our emmision designator to 11K0F30 I think it is and that does not need a freq coordinator, but we are also consideeing dropping a freq we no longer use off our license. How difficult is that to get done?

Also since we are switching to narrowband, will that increase the ERP on those channels? I would like to bump up our repeater output higher than the 50 watts it is currently at. If not, how we would we go about trying to get that increased as we extended or residency boindaries and some of our members sometimes have trouble receiving pages at their houses.

I hope I do not sound like an idiot here, but these are things I have never encountered or dealt with. I figured easier to get answer here than from the FCC itself. :-)
Dan Collins
Telecommunicator - Cahokia, IL Police Department
Firefighter - Cahokia Volunteer Fire Department
radio230
Posts: 39
Joined: Tue Dec 12, 2006 12:14 am

Re: Narrowbanding / Refarming Help...

Post by radio230 »

I should have added, the freq I want to bump up is 154.340. If that helps you any if you are looking at the license.
Dan Collins
Telecommunicator - Cahokia, IL Police Department
Firefighter - Cahokia Volunteer Fire Department
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The Pager Geek
Posts: 1250
Joined: Fri Jun 21, 2002 10:31 pm
What radios do you own?: Disney FRS

Re: Narrowbanding / Refarming Help...

Post by The Pager Geek »

radio230 wrote: I know we need to change our emmision designator to 11K0F30 I think it is and that does not need a freq coordinator, but we are also consideeing dropping a freq we no longer use off our license. How difficult is that to get done?

Also since we are switching to narrowband, will that increase the ERP on those channels? I would like to bump up our repeater output higher than the 50 watts it is currently at. If not, how we would we go about trying to get that increased as we extended or residency boindaries and some of our members sometimes have trouble receiving pages at their houses.
I would enlist a coordinator since you are looking at doing multiple things to the license, some of which require a coordinator. You can do everything in one shot. Since you are well below Line A, it makes it a LOT easier.

Just by changing to narrowband doesn't increase your ERP, however, going to narrowband DOES DECREASE your coverage by 15ish percent. You stated that you are trying to extend coverage... changing to narrowband will only make it worse.

Coverage studies and options to solve deficiencies are very in depth. Single site vs multi-site, etc.

This is where I defer you to a radio vendor in the area capable of providing these coverage studies and solutions that fit your department and budget.

Good luck!

tpg
Experienced Provider of Useless Information
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