Is That Antenna Allowed? The Real Deal On The FCCs OTARD Rule

The Hackaday comments section is generally a lively place. At its best, it’s an endless wellspring of the combined engineering wisdom of millions of readers which serves to advance the state of the art in hardware hacking for all. At its worst — well, let’s just say that at least it’s not the YouTube comments section.

Unfortunately, there’s also a space between the best and the worst where things can be a bit confusing. A case in point is [Bryan Cockfield]’s recent article on a stealth antenna designed to skirt restrictions placed upon an amateur radio operator by the homeowners’ association (HOA) governing his neighborhood.

Hiding an antenna in plain sight.

Putting aside the general griping about the legal and moral hazards of living under an HOA, as well as the weirdly irrelevant side-quest into the relative combustibility of EVs and ICE cars, there appeared to be a persistent misapprehension about the reality of the US Federal Communications Commission’s “Over-the-Air Reception Devices” rules. Reader [Gamma Raymond] beseeched us to clarify the rules, lest misinformation lead any of our readers into the unforgiving clutches of the “golf cart people” who seem to run many HOAs.

According to the FCC’s own OTARD explainer, the rules of 47 CFR § 1.400 are intended only to prevent “governmental and nongovernmental restrictions on viewers’ ability to receive video programming signals” (emphasis added) from three distinct classes of service: direct satellite broadcasters, broadband radio service providers, and television broadcast services.

Specifically, OTARD prevents restrictions on the installation, maintenance, or use of antennas for these services within limits, such as dish antennas having to be less than a meter in diameter (except in Alaska, where dishes can be any size, because it’s Alaska) and restrictions on where antennas can be placed, for example common areas (such as condominium roofs) versus patios and balconies which are designated as for the exclusive use of a tenant or owner. But importantly, that’s it. There are no carve-outs, either explicit or implied, for any other kind of antennas — amateur radio, scanners, CB, WiFi, Meshtastic, whatever. If it’s not about getting TV into your house in some way, shape, or form, it’s not covered by OTARD.

It goes without saying that we are not lawyers, and this is not to be construed as legal advice. If you want to put a 40′ tower with a giant beam antenna on your condo balcony and take on your HOA by stretching the rules and claiming that slow-scan TV is a “video service,” you’re on your own. But a plain reading of OTARD makes it clear to us what is and is not allowed, and we’re sorry to say there’s no quarter for radio hobbyists in the rules. This just means you’re going to need to be clever about your antennas. Or, you know — move.

Wardriving Tools In The Modern Era

When WiFi first came out, it was a super exciting time. The technology was new, and quite a bit less secure back then—particularly if not configured properly. That gave rise to the practice of wardriving—driving around with a computer, looking for unsecured networks, often just for the fun of it. [Simon] has been examining this classic practice from a modern perspective. 

He’s been at the game for a long time—from back in the days when you might head out with a thick old laptop, a bunch of PCMCIA cards, and dangly antennas. It’s much more advanced these days, given we’ve got WiFi on all different bands and Bluetooth devices to consider to boot. Heck, even Zigbee, if you’re hunting down a rogue house full of Internet of Things gadgets.

Today, when he’s out researching the wireless landscape, he uses devices like the Flipper Zero, the Raspberry Pi, and a Google Pixel 5 running the WiGLE WiFi Wardriving app. [Simon] notes that the latter is the easiest way to get started if you’ve got an Android phone. Beyond that, there’s software and hardware out there these days that can do amazing things compared to the simple rigs of yesteryear.

If you’re out looking for free internet these days, wardriving might be a bit pointless given it’s available in practically every public building you visit. But if you’re a wireless security researcher, or just curious about what your own home setup is putting out, it might be worth looking at these tools! Happy hunting.

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Hackaday Links: August 18, 2024

They’re back! The San Francisco autonomous vehicle hijinks, that is, as Waymo’s fleet of driverless cars recently took up the fun new hobby of honking their horns in the wee hours of the morning. Meat-based neighbors of a Waymo parking lot in the South Market neighborhood took offense at the fleet of autonomous vehicles sounding off at 4:00 AM as they shuffled themselves around in the parking lot in a slow-motion ballet of undetermined purpose. The horn-honking is apparently by design, as the cars are programmed to tootle their horn trumpets melodiously if they detect another vehicle backing up into them. That’s understandable; we’ve tootled ourselves under these conditions, with vigor, even. But when the parking lot is full of cars that (presumably) can’t hear the honking and (also presumably) know where the other driverless vehicles are as well as their intent, what’s the point? Luckily, Waymo is on the case, as they issued a fix to keep the peace. Unfortunately, it sounds like the fix is just to geofence the lot and inhibit honking there, which seems like just a band-aid to us.

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A small, white thermal printer with a cartoon cat face above the paper outlet. It is sitting on a black mat on top of a pale wooden table. A Raspberry Pi sits nearby.

Bluetooth Printer Works With AppleTalk

For retrocomputing enthusiasts, getting old computers to work with newer peripherals can be an exciting challenge or horrible headache. If you need to print out receipts from an old Mac, you might just be in luck now that [Hamin Mousavi] has gotten AppleTalk to work with cat printers.

[Mousavi] uses a Raspberry Pi 4 here in his version of the hack, but any Bluetooth capable computer running Linux should work. His command line screenshots are from a Debian-based system, but you should be able to translate to other systems as needed.

Thanks to previous work on these thermal printers, drivers are available for them on many other systems, so the tricky part comes down to getting the web connection to the printer working through the Linux box and then getting the Mac (in this case an iMac G3) to recognize the printer as something to install.

We’ve seen people do some really interesting things with thermal printers like making them D&D tools, breaking their paper DRM, and even black and white “Polaroids.

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2024 Business Card Challenge: CardTunes Bluetooth Speaker

A business card form factor can be quite limiting, but that didn’t stop [Schwimmflugel] from creating CardTunes, an ESP32-based Bluetooth audio speaker that tried something innovative to deliver the output.

What’s very interesting about this design is the speaker itself. [Schwimmflugel] aimed to create a speaker out of two coils made from flexible circuit board material, driving them with opposite polarities to create a thin speaker without the need for a permanent magnet.

The concept is sound, but in practice, performance was poor. One could identify the song being played, but only if holding the speaker up to one’s ear. The output was improved considerably with the addition of a small permanent magnet behind the card, but of course this compromised the original vision.

Even though the concept of making a speaker from two flexible PCB panel coils had only mixed success, we love seeing this kind of effort and there’s a lot to learn from the results. Not to mention that it’s frankly fantastic to even have a Bluetooth speaker on a business card in the first place.

The 2024 Business Card Challenge is over, but judging by all the incredible entries we received, we’re thinking it probably won’t be too long before we come up with another sized-constrained challenge.

Continue reading “2024 Business Card Challenge: CardTunes Bluetooth Speaker”

Nine men of various ages and ethnicities stand in a very clean laboratory space. A number of large white cabinets with displays are on the left behind some white boards and there are wireless charging coils on a dark tablecloth in the foreground. In the back of the lab is a white Porsche Taycan.

Polyphase Wireless EV Fast Charging Moves Forward

While EV charging isn’t that tedious with a cable, for quick trips, being able to just park and have your car automatically charge would be more convenient. Researchers from Oak Ridge National Lab (ORNL) and VW have moved high-speed wireless EV charging one step closer to reality.

We’ve seen fast wireless EV chargers before, but what sets this system apart is the coil size (~0.2 m2 vs 2.0 m2) and the fact it was demonstrated on a functioning EV where previous attempts have been on the bench. According to the researchers, this was the first wireless transfer to a light duty vehicle at 270 kW. Industry standards currently only cover systems up to 20 kW.

The system uses a pair of polyphase electromagnetic coupling coils about 50 cm (19″) wide to transfer the power over a gap of approximately 13 cm (5″). Efficiency is stated at 95%, and that 270 kW would get most EVs capable of those charge rates a 50% bump in charge over ten minutes (assuming you’re in the lower part of your battery capacity where full speeds are available).

We’ve seen some in-road prototypes of wireless charging as well as some other interesting en route chargers like pantographs and slot car roads. We’ve got you covered if you’re wondering what the deal is with all those different plugs that EVs have too.

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Wireless All The Things!

Neither Tom Nardi nor I are exactly young anymore, and we can both remember a time when joysticks were actually connected with wires to the computer or console, for instance. Back then, even though wireless options were on the market, you’d still want the wired version if it was a reaction-speed game, because wireless links just used to be too slow.

Somehow, in the intervening years, and although we never even really noticed the transition as such, everything has become wireless. And that includes our own hacker projects. Sure, the ESP8266 and other WiFi-capable chips made a big difference, but I still have a soft spot in my heart for the nRF24 chipset, which made at least point-to-point wireless affordable and easy. Others will feel the same about ZigBee, but the point stands: nothing has wires anymore, except to charge back up.

The reason? As this experiment comparing the latency of many different wireless connections bears out, wireless data links have just gotten that good, to the point that the latency in the radio is on par with what you’d get over USB. And the relevant software ecosystems have made it easier to go wireless as well. Except for the extra power requirement, and for cases where you need to move a lot of data, there’s almost no reason that any of your devices need wires anymore.

Are you with us? Will you throw down your chains and go wireless?