[hughrr]

Make sure you read the "beware of clones" section carefully. There are some real shysters out there. Even the official UK reseller of the "lesser" sub 1GHz NanoVNA has been caught shipping cloned crap that doesn't even pass self test or work properly on multiple occasions.

On to more optimistic things: these are really good. My neighbour is fairly deaf and has her television obnoxiously loud watching snooker until gone midnight. I asked her politely to turn it down before and was told to fuck off. So as it's on digital terrestrial broadcast TV and we have a shared antenna, I looked up the channel and frequency and set up a fairly narrow band sweep across it and connected the NanoVNA to my TV feed line. She got fed up after about 5 minutes of it cutting out every couple of seconds and turned her TV off.

That's not what I bought it for but that has been my favourite use so far. I originally purchased it to test some 70cm HT antennas.

[CamperBob2]

The clone thing is more controversial than it appears at first. What actually happened was more like this:

1) The original NanoVNA developer publishes the design and quits the field.

2) OwoComm redesigns it for wider coverage, making extensive changes and substantial improvements. She releases the design under the GPL.

3) Some people in China start building clones such as the SAA-2N and making useful improvements of their own. They sell these clones at ridiculously low prices, which are only slightly profitable if at all.

4) OwoComm goes nonlinear and attacks the cloners with everything she has. (Un)fortunately she doesn't have much, because the GPL contains no anti-dumping provisions and the cloners did nothing to violate the extremely liberal license she used.

5) OwoComm does the only thing that makes sense, and returns to the drawing board to create an improved design of her own. Unfortunately the newer designs are closed, due to her previous negative experience with cloners.

It's more complicated than this, in that some of the recent clones have been accused of violating the GPL by failing to release their modified sources. But OwoComm has also not reacted in the most professional manner. The clone vendor hugen, in particular, has added quite a bit of value to the product and (as far as I can tell) has behaved in good faith, but he has been at the top of OwoComm's (s)hit list since the SAA-2N's release.

Kind of a bummer, because these are all some very talented engineers who have, collectively, delivered some amazing hardware to lots of people who would otherwise have been unable to afford anything like it. It's also true that there have been a lot of complete garbage clones released, but the one I mentioned is not one of them. It's a legitimately incredible piece of hardware. Painting all of the clones with the same brush does not capture the reality of the situation.

[dhdc]

Be careful, this isn't something you should talk about/admit in public at all. Feds really don't like it when people mess around licensed bands.

[MertsA]

That's on a shared antenna so no significant broadcast going on, just interfering on the local coax. Never heard of antennas being shared between homes before like that but if it is what he says then it'd be too low power to matter outside of what's directly connected.

[R0b0t1]

Interfering with her reception of broadcast TV is what is illegal. It doesn't need to impact more than one person. Cable is a different matter, you could try for civil damages but I see that as unlikely to get anywhere.

That said, being too loud is interfering with someone's life, so personally seems fair.

[MertsA]

>Interfering with her reception of broadcast TV is what is illegal. It doesn't need to impact more than one person.

That's not illegal, also this was in the U.K. Governments regulate the airwaves, that authority ends at the antenna. As the original poster already stated in a separate comment, he never transmitted anything that would have meaningfully broadcasted any interference on a licensed frequency band. This is no different than cable, especially considering back in the day cable networks were created to distribute broadcast channels from big antennas at their head end.

[hughrr]

This was after weeks of problems and disturbed sleep for a family of 4 and multiple neighbours. And she eventually got a written warning from the local council noise control officer. The immediate thing that follows that is an antisocial behaviour order, usually applied to violent teenagers and the like.

Being respectful of your neighbours is a little understood concept for some people and age and/or disability doesn't exclude your social responsibility to others.

[hughrr]

it's about -8dBm into the feed, which is quite lossy so basically nothing and the antenna is a yagi so directional with little gain as it's receive optimised. It mostly just overloads the AGC and preamp on the front end of the other television pushing the signal below the noise floor.

[hughrr]

We have Ofcom here. I have dealt with them before on behalf of someone else.

They didn’t even do anything to someone we located and identified and collected evidence for who was jamming amateur radio repeaters.

[MegaDeKay]

The advice to "beware of clones" is good advice that applies to the HackRF SDR as well. Despite HackRF being open source, it doesn't mean all clones are good clones.

https://greatscottgadgets.com/2021/12-07-testing-a-hackrf-cl...

[jacquesm]

Do you realize you just admitted to a crime?

[hughrr]

I try and commit at least one every day :)

[jacquesm]

Committing them is one thing, admitting to them in open fora is another.

[trhway]

as a crime it may a be a small one. As a totally lacking empathy a*hole who denied a hearing impacted grandma her favorite show he is definitely a big one though.

[hughrr]

For reference, the local council noise control officer eventually gave her a written warning. She's the asshole for knowingly not being respectful of multiple neighbours' basic requirements for sleep. Even when I approached her nicely about it, after taking her bins out for 5 years, the response was "fuck off" and the door slammed in my face.

Sometimes the only way to deal with an asshole is serve them their own medicine.

And in no way does age or disability excuse poor behaviour. I know that as a parent of a disabled child with mental health issues...

[jacquesm]

There's that.

[PhantomGremlin]

There's probably a market for a sub $1 "smart chip" that can be added to a design. Something that can be factory programmed with a unique serial number. To keep from being cloned, verification operation wouldn't be as simple as reading out the number. Instead, the chip would respond with some sort of hash. Similar to how Apple secures their SOCs.

The security wouldn't need to be perfect. Even something simple would be sufficient to deter an unscrupulous reseller.

[genmud]

There are a bunch of options out there for doing this. Many ICs have built in key storage, but there are a few that are separate. There are some pros to using on micro key management, but one of the big cons is that many times the auth can be bypassed if you can overwrite or glitch the firmware.

If I were concerned about counterfeit things, in an application like this, you would pre program each one with a unique key and everything would be tied to it. Firmware upgrades need to be validated, to download, you would need the key, run the software, key needs to sign something back… etc.

https://www.microchip.com/en-us/product/ATSHA204A

[myself248]

https://octopart.com/atsha204a-sshda-t-microchip-77761819?r=...

But the original would have to see it coming and put this in the design, AND maintain a registry of all the valid chip serials. No hobbyist wants that headache.

[triactual]

What if I buy one real device and clone the serial number? This has been solved more than a decade ago but it requires hardware with secure storage to maintain a private key. Some centralized service holds the public key and can verify the device by asking it to sign something with the private key. This is basically every cell phone, quality IoT device, etc. The private key is installed in the factory, maybe provided by a secure connection back to the centralized service. Hardware features lock that key in place preventing it from being read out without a ton of work (connections are literally burned open with overcurrent inside the IC).

Since the key is unique to the device, it can easily be disavowed in the central database if a device does become compromised. Anything less than this is probably a few hours from being completely broken. And this scheme can be broken by non-state actors, especially if the private key storage is naively or poorly implemented. Many MCUs have multiple levels of readout protection and it can be easy to misconfigure. A single mistake in memory mapping could expose information on external interfaces. And then you’re trying to do all of this in China, on the cheap. Pack a lunch.

[myself248]

Did you read the datasheet or are you responding to your imagination?

Anyway, there's a litany of similar devices to fill whatever requirements you wish. SIM cards, for instance, are available in WSON8 MFF2 chips that you can directly solder to a board.

[triactual]

Why are you so rude? I am a hardware engineer and I’m explaining how you establish trust with hardware devices. This information isn’t contained in a single data sheet, it spans an entire global supply chain.

A SIM card is just one way to do exactly what I described. It’s expensive and probable not a good choice for small, cheap devices. Not to mention brings along a whole host of associated security complexity.

[andi999]

1$ in component price is like 4$ in device sales price. It needs more to be in the 5 cents range.

[buescher]

They make ‘em for secure key storage. The kind of drm scheme you’re describing, though, is not going to be too challenging for someone to subvert who’s already willing to use any of a number of methods to have firmware read off a protected chip.

[R0b0t1]

It's not DRM but serial or secret registry. It allows you to voluntarily check the product you've received against a known list of vendor produced products to allow you to detect a counterfeit.

With the customer as a willing participant such things are hard to subvert.

[GrumpyYoungMan]

There are inexpensive RFID tags with anti-counterfeiting features meant for retail goods, since that's become an increasing problem. They're primarily intended for retailer use since ordinary people don't have a RFID reader but since RFID readers are getting cheaper all the time, there is talk about consumers being able to authenticate their goods as well sometime in the future.

[rsaxvc]

One challenge - authenticity checks need to be done end-to-end(where we that end may be)

If you had such a chip, who would check it for authenticity? That check would need to be well secured, so likely not the ARM firmware on the nanovna itself.

Possibly not nanoVNA-saver: the unscrupulous supplier might just include an unlabeled CDR with patched software.

[R0b0t1]

They have this, people just don't use them. A lot of MCUs have the functionality built in now.