[thangalin]

I develop radio transceiver software for FCC-compliant radios.

The FCC helps ensure that specific radio bands are allocated for emergency purposes. There are regulations based on numerous performance characteristics of radios that must be met before a radio transmitter can be sold and operated. The problem with pirates is that they either aren't aware of these considerations or don't care. Either way could lead to interference with firefighters, police, or ambulance dispatch in life-critical situations. (The P25 digital radio communications standard was written specifically to address interoperability between different manufacturers, as a direct result of the inability for first responders to coordinate efforts during 9/11, which led to more lives lost than would have happened otherwise.)

Beyond the FCC, counties need to stay within their allocated spectrum band, lest they interfere with neighbouring transceivers.

Yes, corporate radio is trash. In Canada, we have CBC Radio, which is free of advertisements. Allowing radio pirates to jam airwaves is neither a good idea nor a good solution to corporate crap.

[ctoth]

Okay, now, can you explain to me how an FM transmitter, transmitting somewhere between 87 MHz and 108 MHz will interfere with your emergency services? Potential harmonics? Can you point at one case of this ever happening, ever in real life where modern emergency communications were interrupted by a FM transmitter?

[rsaxvc]

> can you explain to me how an FM transmitter, transmitting somewhere between 87 MHz and 108 MHz will interfere with your emergency services

Jamming EAS(https://www.fcc.gov/emergency-alert-system). In the rural midwest, it's critical for distributing tornado warnings further from town than you can hear the sirens. Periodic tests are required, and there's a readiness report.

>Can you point at one case of this ever happening, ever in real life where modern emergency communications were interrupted by a FM transmitter?

EAS failures due to interference causing poor signal does happen. From the August 11, 2021 Nationwide EAS Test: "There were 78 test participants on receipt and 32 on retransmission that reported failure to receive the test message due to poor signal. Test participants attributed the poor signal to interference, a weak signal from their monitoring source, or a weather-related complication."

Also from https://www.govinfo.gov/content/pkg/CRPT-115hrpt843/html/CRP... ,

"Illegal pirate radio stations interfere with the Emergency Alert System (EAS). EAS is critically important to protect the public and national security. During national, regional, and local emergencies, the broadcast EAS system is essential to saving lives. Stations participating in the EAS system must be able to transmit and receive interference-free signals. Pirate stations do not participate in the EAS system and do not comply with FCC's EAS rules monitoring and broadcasting EAS alerts. Further, unlicensed illegal stations interfere with licensed radio stations. Such interference affects EAS alerts that are broadcast by licensed radio stations. Thus, consumers located near a pirate radio transmitter will not hear the legitimate station's EAS alert."

[bb88]

> Jamming EAS(https://www.fcc.gov/emergency-alert-system). In the rural midwest, it's critical for distributing tornado warnings further from town than you can hear the sirens. Periodic tests are required, and there's a readiness report.

Not just the midwest. Anywhere there is not cell service where there might be some kind of an alert that needs to be generated. AM, FM, and the weather bands are often the only reliable signals that can be received in some areas.

Flooding, tsunamis, avalanches, nuclear power plant warnings, civil defense warnings, etc all have SAME codes.

See page A-13 for all the codes that SAME provides. https://www.nws.noaa.gov/directives/sym/pd01017012curr.pdf

[brightlancer]

> EAS failures due to interference causing poor signal does happen. From the August 11, 2021 Nationwide EAS Test: "There were 78 test participants on receipt and 32 on retransmission that reported failure to receive the test message due to poor signal. Test participants attributed the poor signal to interference, a weak signal from their monitoring source, or a weather-related complication."

Out of how many test recipients? If I'm reading the report correctly, it was at least 19,302, which means interference caused failure for < 0.6% -- and the overall failure rate was slightly higher than 10%.

https://docs.fcc.gov/public/attachments/DOC-378861A1.txt

I understand that any interference could potentially cause loss of life, but I wonder how much illegal "pirate" broadcasts are really a factor.

[rsaxvc]

Dunno - they don't break it down any further.

This may have some amount of survivorship bias in that remediated interference won't count toward those failures.

[Gordonjcp]

Doing something like that on VHF is utterly idiotic if you need to cover a large area, unless it's as flat as a snooker table.

Do it on SW, around 6MHz, and you'll cover a 300-mile radius with 50 watts.

[RF_Savage]

But weather is more local. 6MHz might not get that good of a range with low powers like that thanks to the really high amounts of man made noise on HF bands.

So the inherently local nature of VHF complements the inherently local weather alerts. Floods and tornadoes are not an issue at a distance of 300 miles.

[rsaxvc]

That seems rather limited compared to EAS in practice, since some EAS stations will relay appropriate alerts, and since EAS runs over both broadcast FM, AM, and TV stations.

[jrockway]

Real life communications have been interrupted by faulty sump pump motors and bad LED drivers. Actually trying to build a radio is no guarantee of success.

A long time ago, we were acquiring the shadiest RF devices possible to test against our WiFi routers, which should avoid auto-selecting interfering frequencies. One device we got was an analog wireless security camera thingie bought right from Amazon. "2.4GHz" it declared, so it was the perfect test case. We turned it on and there was no WiFi interference whatsoever. We got out the test equipment and... its carrier frequency was right on the edge of the L1 GPS frequency. You turn the thing on, there goes GPS for the neighborhood. It was impressively disastrous and we did not test it any further!

That's a company trying to build a radio product, for sale to consumers in the US market. I don't have a lot more faith in random people trying to build FM radios. Sure, you'll know if it doesn't work, because you tune your car radio to it and you can't hear anything. But unless you're careful, you can radiate a lot of power in the sidebands and the harmonics. That will trash licensed spectrum users, which is Not Nice Of You. (As for "amateur radio" operators, how to build and test radios is part of the exam, so there are a lot of great homebuilt radios floating around out there. Also part of the test is knowing when you can use non-amateur frequencies, and what the punishment for doing so is. Needless to say, not a lot of trained hams are building pirate radio stations. So that brings the likelihood of doing a bad job even higher; by definition, only the unlicensed and untrained are even trying this.)

This comment is already too long but I want to relay another fun fact. Building a receiver can interfere with other users of the spectrum; a common design mixes the incoming radio signal by a higher frequency, filters it, and then mixes it down to audio frequencies. If you don't shield this well, then your receiver is actually a transmitter on some random other band. Be careful and test your design with a spectrum analyzer. It's not rocket science but it's not trivial either.

[JumpCrisscross]

> can you explain to me how an FM transmitter, transmitting somewhere between 87 MHz and 108 MHz will interfere with your emergency services

In isolation it’s a dice roll. Normalise it and the game becomes power: since nobody is coördinating spectrum, the loudest transmitter (noisily) wins. Waiting until that predictable point doesn’t make sense, particularly given the FCC seems to have warned this guy in the past without handing out a fine.

[lajupechere]

It’s not emergency, but i would consider an airport to qualify. The airport on Orcas Island, WA had harmonics issues from someone running an illicit FM transmitter in 2018.

[RF_Enthusiast]

Another one is in California: https://docs.fcc.gov/public/attachments/DOC-128793A1.pdf

More recently, a construction permit on 107.9 was cancelled after it was determined that it could not co-exist with an airport. (If I find the link, I'll edit this reply and post it)

[FL410]

The transmitters near John Tune airport in Nashville regularly interfere with avionics. Been that way for years, and no action....

[RF_Enthusiast]

John Tune airport should complain. Interference with air traffic is one of the highest enforcement priorities with the FCC. They'd probably show up as fast as they could drive there.

[Gordonjcp]

> Okay, now, can you explain to me how an FM transmitter, transmitting somewhere between 87 MHz and 108 MHz will interfere with your emergency services?

The fifth harmonic will land squarely in the chunk of band between about 435MHz and 500MHz, and being roughly 200kHz wide even assuming they're not overdeviating like hell it'll obliterate a huge chunk of the band. Given how poorly constructed many "pirate TXes are it's almost a given that they'll have ridiculous amounts of out-of-band radiation.

There's one very popular design available on the Internet which I won't link to but will leave as an exercise for the reader, which has a rather nasty sproggie that's only about 10dB down at around 156MHz when it's tuned for about 104MHz. Now, that chunk of the FM broadcast band is quiet around here, but the sproggie passes through the transmitter's largely untuned (at least, broad as a barn door) PA and out the antenna.

The whole thing is not terribly efficient at radiating something 200kHz wide all over the bottom end of the Marine VHF band, but it sure is noticeable.

Source: literally my day job.

[RF_Savage]

I have measured some cheap aliexpross specials and they ware remarkably dirty. A forest of spikes around the fundamental thanks to parts of the TX strip oscillating. I guess the manufacturers just pulled every last bit of gain and output power from their transistors with minimal amounts of additional parts. And the end result is something you cannot run even if you had a licensed FM broadcast band frequency.

[Anarch157a]

Some years ago, here in Brazil, I saw a news report on TV where they played a recording from an ATC tower where you could hear a pirate station talking over their transmissions. The pirate station was operated by a church.

[JKCalhoun]

You've made a good point regarding bad pirate transmitters.

I still contend that public-access radio ought to be a thing. It can be a certified station in the same way that cable-access in the 1980's was not "pirate cable".

[phire]

It's a thing in New Zealand.

Limited to a 1w transmitter, so it can only cover a small area. And only a few subranges within the FM band.

But no registration is required, you just need to use pre-approved equipment and anounce your contact details once an hour.

[RF_Enthusiast]

That's funny! I just mentioned that further down in the thread at about the same time as your post.

I think NZ started on FM later than many countries, so they saw the wisdom in reserving some frequencies specifically for that use. Unfortunately that wisdom was gained after the US (and most other countries) already allocated everything.

[phire]

Ah, during the 80s and 90s, they only allocated 89.0 to 101mhz for FM radio due to previous allocations.

When users of of those bands were moved elsewhere (to mobile phones) they expanded to the standard 88.0mhz to 108mhz range in 2000. Looks like they reserved the 1mhz "guardband" of the expanded range for these unlicensed, low power stations.

[kjellsbells]

Maybe LPFM fits your definition? Community FM radio authorized by the FCC. The restriction is that the range is limited, but then again, a tiny community of is not likely to be blasting a kilowatt anyway.

https://www.fcc.gov/media/radio/lpfm

[jrumbut]

I do think, since electronics have become cheaper and the AM/FM dial is becoming emptier these days, that we ought to look into what you're saying as a way to revitalize radio.

Although at this point I think it's on a one way path to being more bandwidth for the Internet (in one form or another).

[TylerE]

Difference is cable was, well, cable. By definition is cannot cause interference.

[finnthehuman]

The FCC has visited a friend because some hardware in their house was causing the cable TV signal to leak into the air and it was causing interference on some aircraft-related frequency.

[stemlord]

Don't all these issues exist BECAUSE fm/am radio has no public access to begin with? Illegal marijuana means no regulation of the supply chain, for example

[saalweachter]

A quick Googling shows that, in the US, at least up until 2013, you could obtain a LPFM (<100W) license from the FCC for free.

https://www.prometheusradio.org/startup_costs

So it kinda seems like it was a thing?

[hakfoo]

I suspect part of the problem is that since there's no "off-the-shelf" solution, and with the entire category being more-or-less off-limits for the hobbyist, pirate-style radio is going to be done with random mispurposed or home-made gear that almost certainly ignores ALL the rules, not just the inconvenient ones.

Is there a "turnkey" solution for someone who wants a broadcast radius bigger than the "talking real estate sign" with a 100-metre radius, but smaller than the smallest commercial/non-profit products? I know there was a lot of talk about low-power FM a few years back, but I think that was still at a level of cost, complexity and licensing far above a lot of the potential audience.

If we had a few nationally allocated free-for-all spots on the FM and TV bands, I'd expect to see such products appear very quickly. Since they'd be made by legitimate manufacturers with the desire to stay in business, they'd generally be well-behaved and have controls limited to stay within bounds, but that would probably be enough to satisfy the niche of "I want to control what's on the radio." Yeah, the channels would be a complete noise mess, but we already did that with CB and the various bands we allocated for Wi-Fi.

[RF_Enthusiast]

Re: Turnkey Solution

Bluetooth Auracast still has a chance at becoming a thing, and is a one-to-many terrestrial broadcast solution that, if implemented by manufacturers, will be available on almost any mobile device. It allows for 4 watts EIRP and it's one-way (no pairing). I could imagine success in a pedestrian-heavy environment.

Re: "...a few nationally allocated free-for-all spots on the FM and TV bands"

The bandwidth unfortunately does not exist for a nation-wide channel in the USA.

[hakfoo]

It seems like we had no problems bumping broadcasters off of the higher UHF channels to open up space to sell to telecom companies, so how hard would it be to reallocate, say, channels 5 and 6 to public use?

I'd expect that a lot of broadcasters left VHF after the ATSC transition, because it seems like most modern TV antennas are UHF-centric designs, and channel 6 is already known for reaching into the bottom of the FM band, so it kills two birds with one stone.

The problem with anything new is that it's like the current appeal of ham radio products in general: the only community it reaches is people who already went out of their way to buy a compatible receiver. You can be relatively sure a "general" audience has standard FM and TV capabilities already.

[RF_Enthusiast]

Channel 5 and 6 LPTV stations are being given the opportunity to upgrade from secondary spectrum user (that could be forced off their frequency) to primary spectrum user (that can't be forced off their frequency). So the option to use channels 5 and 6 just closed, as those frequencies are now used in most markets.

I can't think of one major US market off hand that does not have a channel 5 or 6 station.

[hakfoo]

Phoenix has a nominal channel 5, but it's on RF 17. There's only two notable broadcasters on VHF, both above the FM band (8 and 10).

https://www.rabbitears.info/searchmap.php?request=result&stu...

[RF_Enthusiast]

I checked another source just to be sure, but you're right! Phoenix has an empty lower-VHF dial!

Prescott (Ch 6), Yuma (Ch. 2) and Tucson (Ch 4) have the lower-VHF stations in that region.

[porkbeer]

There are plenty of quality turnkey sokutions, but the price and legal encumberances make them rare in the pirate space.

[sillysaurusx]

Can you help us understand how realistic the concern is that a pirate might interfere with emergency services? Is it that easy?

[RF_Enthusiast]

Broadcast transmitters need certification or other forms of verification as a way to certify that they do not put out spurious emissions. Many uncertified transmitters put out emissions at 10.6 and 21.2 MHz above the operating frequency. 90.5 MHz plus 21.2 equals 111.7 MHz, which is in middle of a band of frequencies used for aircraft navigational aids. You can easily imagine how that can be a danger.

Pirate stations generally don't fork out the extra cash to get a certified or verified transmitter. And uncertified/unverified transmitter manufacturers generally don't test for compliance regarding interference to public safety bands.

[TechBro8615]

Should we be worried about hostile powers building radio transmitters to interfere with emergency broadcasts, but only turning them on before they launch a nuke at us?

[Dalewyn]

This desperate grasping for straw to try and justify illegal use of radio is sad to witness.

Radio is available for use for everyone with proper licensing and certification; there's even a block of frequencies reserved for amateur use (read: ham radio).

The US is a country based on rule of law, your anarchist arguments aren't providing useful discussion.

[TechBro8615]

My comment wasn't attempting to justify use of illegal radio, and your comment was unnecessarily rude, but I'll ignore that (and I won't call you an authoritarian statist).

My comment was questioning the efficacy of FCC regulations against protecting from a "real" threat, i.e. same kind of argument as "gun free zones only stop good guys with a gun while not stopping bad guys with a gun."

If anything, I was asking if there should be more regulations to protect against threats that attempt to obfuscate their presence.

[Dalewyn]

The FCC is, admittedly, reactionary in general because of geographical reality; generally they receive a complaint and then they investigate in response.

Any incidents that go beyond just interference will likely involve other regulatory and law enforcement agencies anyway, so it's unlikely the FCC itself needs more powers for now.

[factormeta]

>Radio is available for use for everyone with proper licensing and certification; there's even a block of frequencies reserved for amateur use (read: ham radio).

yeah, but it is not legal to encrypt the ham radio traffic, kinda defeats the whole point of having a frequency for DIY usage.

[KyeRussell]

No it doesn’t.

[TallGuyShort]

I come across a lot of digital signals and there are people who like to experiment with different digital modes. In practice, it's hard to distinguish this from encryption.

[nuclearnice3]

How would "hostile powers building radio transmitters to interfere" justify pirate radio?

[brightlancer]

I think they meant that if illegal broadcasts are such a danger, should we be worried about hostile powers deliberately exploiting that?

Conversely, if we're not worried, are illegal broadcasts such a danger?

[kmeisthax]

I don't the parent comment you replied to is saying "if Russia hasn't killed our radios yet than pirate radio is fine". They're wondering if it's a potential attack at all - and if you don't know much about radio then that's a perfectly reasonable thing to think. It's only after you learn about energy dissipation and so on that you realize that the hostile power needs to be pretty close to the actual thing they want to jam.

Though it's not like Russia hasn't already tried anyway[0].

I'm pretty sure most people here are going to at least know what ham radio is. That's not the reason why people here are sympathetic to pirate AM/FM radio broadcasters. It's moreso because the AM and FM radio bands are basically a cultural dead zone: ClearChannel and friends bought them all up in decades past and turned them into garbage. This is the sort of misallocation of resources that economists tend to have a blind spot for. According to them, efficient markets[1] are perfect allocators and anyone not having their tastes satisfied are just harbingers of failure[2] angry that their Crystal Pepsi got discontinued. The reality is that there's literally no reason to have eight stations all playing the same mainstream format in one market, and the FCC has dropped the ball on maximizing public utility of the spectrum.

'Cause here's the thing: yes, radio is "available for use" with proper licensing and certification, but that's basically an elaborated no. It's sort of like saying "copyrighted material is available with proper licensing". Nobody is going to be able to afford the licenses, if they're even offered, because the FCC runs on an auction system. And it turns out that that the mainstream station formats are really, really profitable to the point where you can outbid everything else. Is this an actually worthwhile use of the AM/FM bands to have what are effectively duplicates of the same station on every band in every market?

[0] Ok, it was a radar system, not a jamming system, but that's just a difference of intent. See https://www.youtube.com/watch?v=xbi6eoh63ZQ

[1] Fun fact: did you know the Efficient Markets Hypothesis implies P = NP? It's true - if markets are perfectly efficient then they can solve boolean satisfiability problems, which are NP-complete, and thus you can break all crypto.

On the other hand, inefficient markets also imply all those finance soothsayers with their technical analysis can actually beat the market.

[2] "Harbingers of failure" are people who are unusually good at buying doomed products. See https://news.mit.edu/2015/harbinger-failure-consumers-unpopu...

[RF_Enthusiast]

I don't think so. The amount of infrastructure (most notably, power) needed to operate such a transmitter that would make a meaningful impact to emergency broadcasts would raise red flags on the local level well in advance.

[stevenhubertron]

Look at Ringway Manchester on YouTube. Goes deep on this.

[GravitasFailure]

I've had severe radio interference from Mexico while I was about 600 miles from the border and less than 50 from the US station's 5KW transmitter, and I have no idea how much further from the border the Mexican station was. Handheld radios from a business illegally operating on the wrong frequency rendered radio comms at a job site I was working at completely unusable, and those transmitters are less than 1 watt. Your received power is miniscule compared to what even small transmitters are throwing out, so it really doesn't take much to degrade the signal to the point of uselessness, and those are with properly built transmitters and receivers on the wrong channels, forget some amateur station that's blasting noise all over the spectrum.

[salad-tycoon]

What about those little Bluetooth fm transmitters in cars to hook phone up to?

[GravitasFailure]

You mean the FM transmitters so that you can play your music on an empty station? I've had interference from them, too, but they're usually very low power and most useful when not stepping on another station, so there's some incentive to not mess with other stations.

[darepublic]

College radio stations are usually pretty good. i.e in Toronto CIUT 89.5. I occasionally listen to CBC radio but on the whole I find it pretty vapid.

[RF_Savage]

I thought P25 predates 9/11? All those Astro Spectras and Astro Sabers surely predate 9/11?

But 9/11 likely put in much more work into it and multi-band radios that can more easily interoperate.

[thangalin]

You're correct, and I should have fact-checked that rather than relying on my memory of what co-workers have said. Project 25 (P25) was started in 1988/1989; the first compliant radios came out in 2012. At some point after 9/11, it was mandated that all government radios purchased must support P25 (for interoperability), likely as a 9/11 Commission recommendation[1].

[1]: https://majorcitieschiefs.com/wp-content/uploads/2021/10/MCC...

[phpisthebest]

The FCC's primary job is to protect the corporate profits after they pillaged a public good and auctioned it off for peanuts to preferred corporate buyers depriving the public the use of that resource using the false narrative of "public safety" and "public good" as justification for this....

it is shameful people buy into, and believe the FCC method of "allocation" is either good, or designed to "save lives" when clearly that is NOT the primary purpose of the allocation plan

[RF_Enthusiast]

I've purchased bandwidth in a competitive FCC auction and I'm in no way a preferred corporate buyer.

If you replace "preferred corporate buyer" with "highest bidder", that would be more accurate in my experience.

Otherwise, I agree-- "highest bidder" is not a great way to determine what is best for the public.

[hellojesus]

Radio frequencies are not public goods. Public goods must be nonrivalous and nonexcludable. But only one entity can effectively transmit on a given frequency at a time, so it is definitely rivalrous.

Seems the argument should be more that it is a merit good, but even then some determination must be made as to how to allocate each frequency resource. Auctions are a decent way to do that; supply and demand. So long as they are public and truly go to the highest bidder, I'm not sure there is much to be dissatisfied about.

Thankfully the internet exists to allow people to transmit whatever they want; granted it's still limited to the internet so not the same.

[hakfoo]

The idea of "only one transmitter" might have made sense in 1950 for analog signals with no chance of replay, but I have to think we've learned a lot about multiplexing and collision detection.

If we allocated broadcast bands today, would we have a hundred narrow channels, or would we have a smaller number of channels and use a TDMA or CDMA style system to expand the number of available slots? I could even imagine packetized broadcasts-- rather than "KXYZ-FM" being on 98.6, your receiver would just scan the entire band for packets tagged KXYZ, and they could dynamically reallocate based on local noise levels or atmospheric conditions.

[RF_Savage]

That sounds a bit like DAB multiplexes. Except that there is a single transmitter and you buy a slot in it. Cognitive radio with dynamic frequency selection was all the hype along with TV white space radio. But the only actual service that has materialized was the 3.65GHz CBRS one. And that seems to only have been successful thanks to it sharing frequencies with the 3.5GHz 5G bands, making equipment available and affordable.

[phpisthebest]

>>Public goods must be nonrivalous and nonexcludable.

Says who?

>> Auctions are a decent way to do that;

Clearly they are not, nor it is how that is done, as entire segments are portioned off for a use, then auctioned off for that use.

>So long as they are public and truly go to the highest bidder, I'm not sure there is much to be dissatisfied about.

Lots. for one the fact that companies can buy up huge parts of the spectrum for "future use" and sit on it for decades denying access for innovation.

[ilyt]

But that's entirely different issue.

The way to "curb" it would be to just give part of the band as "free for all".

Then they can chase people running shittily designed transmitters separately

[ipaddr]

CBC radio is an advertisement.

What emergency services are operating under its Steeple in this case?

[RF_Enthusiast]

In this case, they're blocking out the Emergency Alert System of KBOO. Since KBOO is operating in HD mode, both stations were occupying the bandwidth between 90.5 and 90.6 MHz. KBOO is charged with providing emergency alerts for the immediate vicinity of the 90.5 pirate, but was compromised there.

EAS is expanding to provide visual alerts as well, which the 90.5 pirate fully blocked.

[djur]

Worth pointing out here that KBOO is a non-profit community radio station, pretty close to the "public access" radio that people here are wanting.

[RF_Enthusiast]

Yes, I think a lot of people don't know what's available (or, at least possible) on their local dial.

It's hard to draw an exact parallel between public access on cable and public access on FM/AM.

Public access on cable is using infrastructure that cable TV companies were required to provide, as a cost for the privilege of using public right-of-ways to run their cables. All costs paid by the cable company.

None of that is in place in the US for radio. Each station has it's own transmitter and must obtain it's own tower space. There's no one to pay for the transmitter, tower and related infrastructure for a public access radio station.

The closest is the currently existing Low Power FM service, and the Non Commercial FM Service, but it's not free, like public access cable is/was.