FCC warns Portland church to shut down pirate FM operating under its steeple

So obviously fans don’t have speakers or Alexa in them, I think.

How does this work for things without speakers to produce sounds? You hear sounds from the motor/wiring?

I never even imagined this was a thing.

> The gold and amalgam tooth fillings did not act as an antenna or point-contact transistor when placed in a real human skull. Explanations for the supposed Morse code pickup included a Galvanic cell reaction between two teeth fillings and saliva.

> This myth was first claimed by Lucille Ball in an interview on The Dick Cavett Show, with the fillings explanation offered by Buster Keaton.

Back when I was really active in HF, this thing was nuts.

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

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.

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.

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."

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.

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.

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.

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).

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

https://www.prometheusradio.org/startup_costs

So it kinda seems like it was a thing?

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.

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.

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.

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

If it's line-of-sight on a frequency with no interference and stays at the legal limit of 250 microvolts per meter measured at 3 meters, and there's a good receiver with a good antenna, it's possible.

You may think the radio stations are still awful, but it's an entirely different company.

Two wrongs do not make a right.

In this case, KBOO on 90.7 is running HD format, which puts the lower digital shoulder at 90.5 MHz. So this station was operating on top of KBOO, compromising the KBOO signal. 90.5 - 90.6 MHz contained two signals, although the pirate operator didn't know that, as the digital hash sounds like static to the untrained ear.

KBOO did not purchase spectrum as they are a noncommercial station, and those stations are not subject to application or regulatory fees. KBOO has the same rights to the 200 kHz for analog and the additional digital bandwidth on either side, as any licensed FM station in the US has (expect for perhaps some FM translators).

As for analog vs. analog on adjacent frequencies, they interfere with each other, because there's a little bit of overlap. Analog signals don't have that "cliff" that the band edge that digital signals have. Analog FM can fit right next to digital, because the digital signal stops right at the edge. But the little bit of overlap of a 101.3 signal onto 101.5 is doubled when you consider the little bit of overlap from 101.5 to 101.3. It's significant interference on a receiver.

If you look at the lineup of licensed stations in any one location, you'll notice that stations are spaced by at least one vacant channel. For example, in most cities you'll see an alignment like this: 101.3 (full power), 101.7 (low power or distant), 102.1 (full power), 102.5 (low power or distant).

A full power station can't be in the same vicinity as another full power station for 3 adjacent channels. That is probably overkill, as it's made with consideration for receivers made decades ago that are no longer in use.

Pretty much, yes. There are always guard bands allocated, plus careful calculations to avoid harmonics, intermodulation products, images, etc, which could interfere with other services.