Help identifying digital...

[oregontreehugger]

I noticed some listings in my area with a "20K0F1E" designator. Does this mean those frequencies are digital?

On some frequencies there is the above designator as well as a "20K0F3E" designator. Does this mean they are dual-licensed for digital and analog?

For example, an FD used to page via regular tones -- now there's a squelch break for a brief millisecond (no buzzing or funny data noise, though, just sounds like someone keyed the mike without talking) and then the dispatcher gives out the call information. You never even hear the tone page.

Is it possible to use page-out tones briefly with digital and then switch to analog mode to give the details? Backwards compatible or something like that? Maybe they are testing the new digital stuff?

Shucks. I hope I don't have to cough up for a digital scanner!

Thanks for any insight... I am new to the digital stuff.

 

[pfish]

This page should explain all of your questions: http://wireless.fcc.gov/services/ind&bus/licensing/emission.html

 

[digitaljim6]

Or even this spreadsheet:

http://www.radioreference.com/modules.php?name=Downloads&d_op=getit&lid=11

 

[digitaljim6]

So the 20K0F3E is a 20.0 KHz wide frequency-modulated (FM) analog voice channel and the 20K0F1E is a 20.0 KHz wide frequency-modulated (FM) digital voice channel.

For digital voice usage like the 20K0F1E listing, the type of voice encoding used and the type of encryption, if any, is not part of the emission designator.

 

[N_Jay]

So the 20K0F3E is a 20.0 KHz wide frequency-modulated (FM) analog voice channel and the 20K0F1E is a 20.0 KHz wide frequency-modulated (FM) digital voice channel.

For digital voice usage like the 20K0F1E listing, the type of voice encoding used and the type of encryption, if any, is not part of the emission designator.

Was goingto say something but checked and I was WRONG!

 

[RyltnVFD]

Was goingto say something but checked and I was WRONG!

Whoa, a pig just flew over the moon, and Satan put on a winter coat!

 

[Thayne]

Pretty mellow, I must say--this is hard to believe!

 

[DaveNF2G]

Regarding the situation described at the beginning of the thread ....

Did the local service change frequencies when putting in the new system? Analog audio tones might still be sent over the original alerting frequency. You might check the old channels for activity.

Here in upstate NY, the Town of Colonie (Albany County) uses a Motorola 800 MHz trunked system for all two-way communications. Paging or home alert tones and voice announcements are sent over the old fire dispatch channel on VHF high band, and the station sirens are activated using QuikCall 2+2 tones on VHF low band. The voice announcements are simulcast on the trunked system, but not any of the tones.

 

[digitaljim6]

To answer another of the initial post's questions:

Yes, the "dual" emission designation of 20K0F3E along with 20K0F1E would describe a channel that is licensed for both analog voice and digital voice. The reason, as you speculated, could be transition, interoperability, compatibility, testing, or they just want to be able to do either as they see fit.

It may or may not have anything to do with alerting tones. As is stated elsewhere in this thread about the system upgrade/replacement situation, it is common to send the alert tones on the "old" analog channel and give the voice dispatch on both old and new. This satisfies the pager users as well as radio users who are listening to an old radio or a new radio.

 

[oregontreehugger]

Thanks for the information and tips!

It appears that digital might be in store for the future. Many other frequencies appear to be dual licensed for analog/digital.

I will have to keep my eyes on the local papers and see what kind of details, if any, pop up.

As far as 800MHz, hardly any here, and none for government use. And strangely enough, no change in local frequencies, either. Just that new dual analog/digital licensing I noticed. Unless someone is operating without an FCC license!