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I’m super new to radio with nobody I know knowing it, so noob alert - plus some extraneous details in case you can comment on any of those.

I got a pair of BaoFeng BF-F8HP radios with recommended antenna upgrades with the idea that my brother and I can eventually get licensed and talk over the 5 miles between our houses in dense suburbs. Seems plausible from the reviews, but haven’t tested yet.

Anyway, we’re just listening for now and there are a few emergency services I found through radioreference. Most in my area are encrypted and some are at like 700+Mhz that are beyond this radio’s uhf & vhf bands. (I think I can pick up P25 and FM, but not other modes). I was able reach more stations by decreasing the Freq Step size to the minimum 2.5khz, and also going to Narrowband mode for easier scanning (although scanning has been fruitless). Infrequently I hear morse go out on the otherwise vox channel. Perhaps they’re different bands and my narrow-band is still too wide? I haven’t found any broadcasts that sound like anything but regular old walkie talkies.

Main question: Why don’t these unencrypted FM emergency services seem to use any call signs or ham codes? Are they not required to because they aren’t operating as “amateur”s? And if not, why wouldn’t that type of activity get isolated bands instead of mixing two different vocal protocols in the same bands? And if I broadcast on any of the vast empty areas of the spectrum as a range test, who would know I wasn’t just some emergency/government service?

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… Why don’t these unencrypted FM emergency services seem to use any call signs … ?

They aren't required to and don't find it useful in their procedures. Also, they don't have call signs in the sense amateurs do — they may have names for different groups in a transmission ("Car #3" or whatever) which are call signs in the sense that they play the same role in radio procedure, but they're not related to radio licensing at all — they're made up for the organization's purposes.

Are they not required to because they aren’t operating as “amateur”s?

Yes. Amateur licensing is completely unrelated to licensing for commercial or government two-way radio.

Amateur radio licenses are granted to a person for their operations, with whatever equipment they like. Commercial and government licenses (in the US, and I would expect similarly elsewhere) are granted to an organization — the individual users do not use any license of their own in order to participate. The organization purchases or rents radios and, usually, "programs" them to operate only on the frequencies they have a license to (so the individual users cannot violate the license and don't have to think about frequencies, just a small list of preset channels).

And if not, why wouldn’t that type of activity get isolated bands instead of mixing two different vocal protocols in the same bands?

They are isolated. The transmissions you are listening to are not in the amateur frequency allocations (bands). Your local radio licensing authority keeps track of the licenses/allocations. (For the FCC in the US: here's the table of allocations and the search engine for individual licenses — including by frequency.)

And if I broadcast on any of the vast empty areas of the spectrum as a range test, who would know I wasn’t just some emergency/government service?

Whatever frequency you pick probably belongs to somebody. They'll have expectations about how their licensed allocation is used, and possibly recognize you as not anyone they know and not following any procedures they have. Or, it could be that the allocation in question is used for an incompatible mode (digital something-or-other) in which case you're just another source of RFI.

Would you "get caught"? Often not, but think of it like trespassing on someone's land — they often might not notice, and they often might not care — or they might care a whole lot. And it's rude, too.

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    $\begingroup$ Whatever frequency you pick [...] belongs to somebody. $\endgroup$ – Mike Waters Aug 10 at 20:06
  • $\begingroup$ Emergency FM systems as I'm used to do have specific callsign conventions, but it's not user-specific (or even station-specific, necessarily), but role-specific. Something like "I'm the leadership crew vehicle machinist of the Karlsruhe branch of the German technical civil protection agency", encoded in numbers. $\endgroup$ – Marcus Müller Aug 10 at 20:32
  • $\begingroup$ @MarcusMüller I meant to specify that, but I've edited the paragraph to make it clearer. $\endgroup$ – Kevin Reid AG6YO Aug 10 at 20:46
  • $\begingroup$ @KevinReidAG6YO thanks! I like this answer. $\endgroup$ – Marcus Müller Aug 10 at 20:47
  • $\begingroup$ I’m getting it. This radio works for multiple use cases including ham, but not limited to ham. $\endgroup$ – Jason Kleban Aug 10 at 21:26
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Why don’t these unencrypted FM emergency services seem to use any call signs or ham codes?

They are required to identify periodically and they do. That is the Morse code you heard.

Emergency services (police, fire, EMS) along with taxicabs, tow trucks, anything else that moves on land, is licensed under part 90, Private Land Mobile Service, of the FCC regulations (in the US, other countries similar). The FCC issues a station license with a call sign to the agency. The license generally covers one (or more) base station and some number of mobile units.

In the past operation was simplex, base station to mobile, and the base station operator would periodically announce the call sign by voice. Now, most operation in via repeater. The repeater will automatically send the station ID by Morse code so the human operator does not have to bother with it. Only the base station has to identify.

Most FM systems will use CTCSS. They leave the tone off when identifying so anyone monitoring the channel with tone squelch enabled will not be bothered by the ID. I don't really know how P25 systems identify.

Note: CTCSS = "Continuous Tone Coded Squelch System" = PL (a trade mark). A system that adds a low frequency audio tone to a transmission. Receivers may enable tone access so they will only hear transmissions with the proper tone.

Addendum: I can see some potential for confusion between answers. Just keep in mind that a land mobile system (e.g. county fire/EMS dispatch) operates as a isolated system. The FCC license and callsign applies to the entire system. Units within the system only talk between units in that system. They don't make random contacts like hams do nor travel outside their jurisdiction. Identifiers for individual units (or people) are assigned by the agency (e.g. "Engine 27", "Chief 15", "Ambulance 498"). That is what they use when communicating within the system. (Then there are some variations such as mutual aid, but let's not get any more complicated).

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  • $\begingroup$ P25 is digital. The amount of data in an identifier (say, if you want to be really generous, say, 64bit) is vastly outswamped by the amount of data you need to convey voice (say, 4400 bit/s for voice in the old P25 phase 1). So, sending an ID for a digital system within a frame is practically "free". Also, P25 supports point-to-point cryptography. If nothing else, handsets can be identified using the cryptographic keys they use. $\endgroup$ – Marcus Müller Aug 10 at 23:14
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who would know I wasn’t just some emergency/government service?

There's national regulations agencies that monitor the spectrum, and come when someone notifies them of an interference. They can fine you! (And: Typically will fine you if they find you in intentional abuse of spectrum.)

Also, be a bit careful about not accidentally using a military allotment. Depending on the service, your country's attitude towards that and the mood of whoever is in charge of the military devices you're interfering with: Visits by these guys will probably not be overly pleasant.

Location of a radio emitter is a lot easier than you might think, especially if you're an agency not afraid of spending a couple dozen kilodollar on radiolocation systems (which are commercially available).

I fully agree with everything Kevin wrote: don't test your luck, and don't interefere with someone's potentially life-critical systems. It's plain rude and inconsiderate!

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    $\begingroup$ Yes! And would you enjoy being behind bars in a prison? Think it over very carefully. ;-) $\endgroup$ – Mike Waters Aug 10 at 21:09
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    $\begingroup$ to be honest, in most places you'd have to interfere pretty hard to end up in jail ;) But then again, on electronics.SE there are people asking about how to set up pirate TV transmitters in civil war zones. That's an easy way to end up worse than in prison :( $\endgroup$ – Marcus Müller Aug 10 at 21:33

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