PA & Narrowbanding

[cdavisjr]

I'm trying to better understand the required narrowbanding changes as I do an end of year re-verification of my scanners content, maybe someone could help clarify it a bit. If an agency of any kind adds one of the 2 narrowband emissions to their licenses are they most likely then staying with their current frequencies? Looked for a vhf conversion chart like there is everywhere for the railroads but kept coming up empty.

 

[GTR8000]

There is no requirement to change frequencies as a result of the narrowbanding process. You won't find any "conversion chart" because none exists. No one is being forced off their current frequencies, by and large they will remain exactly the same.

What needs to be changed is the amount of bandwidth the radios occupy in the spectrum when they transmit. They must occupy no greater than 12.5 kHz after the December 31st, 2012 narrowbanding deadline passes. Currently they are permitted to occupy up to 25 kHz worth of spectrum.

For the most part, you will simply see the agency add the 11K0F3E, 11K2F3E or 11K3F3E emission designators to their licenses to indicate they are narrowband compliant...on paper, at least. They still need to make sure the physical hardware is compliant.

By the way narrowbanding affects UHF also, not just VHF. All Part 90 frequencies between 150 MHz and 512 MHz are affected. Generally speaking, that means frequencies between 150 MHz through 162 MHz (excluding Railroad, Marine and Federal Government) as well as 450 MHz through 512 MHz (excluding GMRS).

 

[cdavisjr]

Thanks Chauffeur,

That pretty much clarified everything I was wondering. So as I am not looking for actual frequencies to be replaced, is it then smart persay as I go through my records to go ahead and make they NFM in my scanners, knowing they eventually will "physically" retune themselves?..and if I do that will I notice a big difference before they switch things?

 

[radioman2001]

Railroads have to narrow also, except they have jumped the gun by forcing any new licensees to 6.25 which means digital and NXDN. Old licensees just have to go 12.5 for now, the AAR (co-ordinator) has advised the FCC of this as a plan to implement 6.25 ahead of any FCC deadline.
Scanners by their nature and design will probably never be true narrow band. You might see a small decrease in their RX bandwidth crystals or design, but I doubt anything further. The only difference you will hear is lower audio.

 

[cdavisjr]

Thanks Radioman,

Not real versed in it but from what I've heard about NXDN and scanners I think we might be better off if they went to just regular digital.

 

[radioman2001]

If the story I heard is true, the AAR would not go with any digital system that Motorola would use in it's products due to them abandoning the Astro Spectra and the support for it.

 

[cdavisjr]

My original question was answewred by all and thank you for that but something I thought about editing and reverifying info for the end of year is if most guys wouldn't need to change their frequencies, just tune them how come the whole railroad frequency platform did have to change frequencies? is it because most guys went originally with a narrowband friendly frequency just not the right emission designator attached to it?....I hope I asked that right.

Carroll