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[-] vk6flab@lemmy.radio 15 points 1 hour ago

For those wondering why. vim is the name of a popular text editor.

[-] vk6flab@lemmy.radio 33 points 12 hours ago

.. cue surprised Pikachu face in November when the GOP candidate wins ..

11

Over the years you've heard me utter the phrase: "Get on air and make some noise!". It's not an idle thought. The intent behind it is to start, to do something, anything, and find yourself a place within the hobby of amateur radio and the community surrounding it.

Since starting my weekly contribution to this community, thirteen years ago, almost to the day, I promise, this wasn't planned, you'll see why in a moment, I've been working my way through the things that take my fancy, things that are of interest to me, and hopefully you. From time-to-time I don't know where the next words are going to come from. Today they came to me five minutes ago when a good friend, Colin, VK6ETE, asked me what inspires me, after I revealed to him that I didn't know what I was going to talk about.

That's all it took to get me rolling.

There are times when getting to that point takes weeks, I do research, figure out how something works, explore how it might have been tackled before, if at all, and only then I might start putting my thoughts together, often I'll have multiple stabs at it and if I'm lucky, sometimes, something emerges that I'm astonished by. Today is much simpler than all that, since the only research required is to remember the people I've interacted with.

Last week I met an amateur, Jess M7WOM, who was in town. Until last week, we'd never met and interacted only online. We discovered that we have a great many things in common. A joy for curiosity, exploration, technology, computers and a shared belief that we can figure out how to make things work. That interaction, over the course of a day, continues to fuel my imagination and provides encouragement to try new things.

The same is true for a friend, Eric VK6BJW, who asked what they should do with the hobby after having been away for a long time with family, children, commitments and work. Just asking a few simple questions got the juices going and provided inspiration to start playing again.

Another amateur was bored and claimed to have run out of things to do. A few of us started asking questions about their exposure to the hobby. Had they tried a digital mode, had they built an antenna, had they tried to activate a park, or as I have said in the past, any of the other 1,000 hobbies that are embedded within the umbrella that we call amateur radio.

Right now I'm in the midst of working through, actually truth be told, I'm starting, Okay, actually, I've yet to start, reading the online book published at PySDR.org. Prompted by a discussion with Jess last week, I started exploring a known gap in my knowledge. I likened it to having a lamp-post in front of my face, I can see to either side, but in-between is this post, obscuring an essential piece of knowledge, how one side is connected to the other. In my case, on one side, I can see the antenna, how it connects to an ADC, or an Analogue to Digital Converter. On the other, I can also see how you have a series of bytes coming into your program that you can compare against what you're looking for, but the two are not quite connected, obscured by that .. post. I know there's a Fourier Transform in there, but I don't yet grok how it's connected.

Recently I discussed using an RDS, or Radio Data Systems decoder, called 'redsea', connected to 'rtl_fm', in turn connected to an RTL-SDR dongle, that is, you connect an antenna to a cheap Digital TV decoder, tune to an FM broadcast station and use some software to decode a digital signal. It turns out that the PySDR book serendipitously uses this signal path as an end-to-end tutorial, complete with all the code and example files to make this happen. I actually read the chapter, but it's assuming some knowledge that I don't yet have, so I'm going to start on page one .. again.

So, what has this got to do with Inspiration, you ask. Well, everything and nothing. Inspiration doesn't occur in a vacuum. It needs input. You cannot see light without it hitting something, radio waves don't exist and cannot be detected until it hits an antenna, the same is true for inspiration. It needs to hit something. You need to react, it needs to connect.

That is why I keep telling you to get on air and make some noise.

I'm Onno VK6FLAB

[-] vk6flab@lemmy.radio 27 points 3 days ago

Spare ribs.

[-] vk6flab@lemmy.radio 26 points 3 days ago

The Romans used bread and games to entertain the masses. Looks to me that this has been fine tuned for the past 2,000 years, only now we call it takeaway and surfing the net.

[-] vk6flab@lemmy.radio 1 points 3 days ago

Okay. I'll bite.

Why does it need to be implemented by Proton, why specifically on Ubuntu Touch, why a VPN?

I realise that the last question might seem odd, but then so does this research: "Novel attack against virtually all VPN apps neuters their entire purpose"

https://arstechnica.com/security/2024/05/novel-attack-against-virtually-all-vpn-apps-neuters-their-entire-purpose/

I might add that this affects most VPN implications since 2002, so, 22 years of oops...

So, I'll ask again, Why?

[-] vk6flab@lemmy.radio 1 points 3 days ago

I don't know what your specific antenna looks like.

Generally you connect close to the centre of the antenna, where the two elements are closest together, again without touching each other.

That said, there are antenna designs where this is not true.

[-] vk6flab@lemmy.radio 2 points 3 days ago

That's understandable, perhaps even desirable, but OP didn't include that in their requirements.

[-] vk6flab@lemmy.radio 4 points 4 days ago

In trying to understand "the rules", you are attempting to understand human nature. In the fediverse there are no "rules", there isn't a governing body, instance owners and moderators essentially have "root" permissions.

Some use those for the greater good, some don't. Some react in ways that are unexpected and unfamiliar.

In other words, be kind to your community and find a place where you can enjoy yourself. Don't fret about the things that you cannot control.

If you absolutely need an answer, set up your own instance and be your own boss.

In the meantime, have fun.

[-] vk6flab@lemmy.radio 5 points 4 days ago

Give us a link instead. That said, read on.

In general, antennas are not like a "normal" circuit where things need to connect to each other to work.

Most antennas are made of two halves or poles, hence the name, dipole.

A Yagi antenna is a dipole with separate elements to focus and reflect the radio waves. These elements are normally not connected to each other.

In a typical Yagi only one pair, the dipole, is the driven element. The many (shorter) elements are directors, the one (or two) behind the driven element is the reflector.

A coaxial cable has two conductive elements, the core (the middle bit of metal) and the shield (the outer braid). These should normally not connect to each other.

You connect each coax conductor to its own dipole element. It generally doesn't matter which coax conductor connects to which dipole element.

Source: I'm a licensed radio amateur.

[-] vk6flab@lemmy.radio 2 points 4 days ago

AFAIK Google is the biggest advertising platform on the planet and the idea that anyone could delete all their content from that platform is not one that I'd consider likely.

I'm happy to be proven wrong, in fact I'd be delighted to be wrong.

[-] vk6flab@lemmy.radio 6 points 4 days ago

Manufacturer warranty?

13

Much is made in our hobby about working DX, that is sending and receiving distant radio signals. How distant is up for debate. Depending on where you are, DX might be outside the continent, outside the country, or in my case you could easily say, anything outside of my state, since the nearest border is about 1,240 km away from here. For giggles, the distance between Albany in the South West and Wyndham in the North East of the state is 2,400 km and that's via radio wave. By car it's 3,570 km. To be clear, we're still inside VK6.

All that to say, DX is in the ear of the beholder.

If that's not enough, there's a group of amateurs who are of the strident opinion that for DX to count it must be a two-way contact. That is, both stations need to hear each other and as such, those amateurs believe that a mode like WSPR, the Weak Signal Propagation Reporter can't possibly be considered DX, even if you can discover that your station was heard on the other side of the planet.

I'm going to skip right over those who tell anyone who will listen that FT8 isn't real radio because it's just computers talking to each other.

This to give you some context when I introduce the next idea, namely FM Broadcast DX. I'm acutely aware that this isn't amateur radio, there's no two-way communication, it's probably not DX and besides, it's computers. That out of the way, let me tell you about something I discovered.

Many, but not all, FM broadcasters transmit multiple signals when you tune to their station. One of those is a signal called RDS, or Radio Data Systems. It's used to show you the name of the station, sometimes what song is playing, what style of station it is and other information like road traffic alerts and emergencies. You can decode this using an RDS decoder.

Recently I was browsing YouTube. I came across a video on the Broken Signal channel that digs into the world of FM-scanning to log any RDS information for the purpose of finding DX stations. The video goes into great detail on how to set this up with Windows, by copying files into various places, updating XML files, configuring sample rates, connecting virtual audio cables, running several tools simultaneously and it goes on to demonstrate how this all hangs together.

While I was impressed with the idea, the implementation didn't speak to me, since I wince at the notion of copying random files into an application installation directory and besides I'm a Linux user.

So, I went hunting.

Turns out that there is an RDS decoder for Linux, called "redsea", written by Oona OH2EIQ. It's on GitHub. Compiling it is pretty straightforward, follow the instructions and it should work as advertised. You'll also need to have "rtl-sdr" installed so you can run a tool called "rtl_fm". Again Oona's instructions should help you out. I will add that I'm assuming that you have a so-called RTL-SDR dongle, it's a cheap USB device that can be coerced into pretending to be a software defined receiver with about 2.2 MHz of bandwidth.

Based on the example shown, I immediately tuned to a local station and RDS information started filling my screen. To let you know how simple this is, you run the "rtl_fm" tool and send its output to "redsea" which decodes the information and displays it on the screen. That's it. No more moving parts, no XML files, no shenanigans with virtual audio cables and the like.

Stage one complete, on to stage two, scanning.

The "rtl_fm" tool has the capability to scan a range of frequencies. I tried this, but didn't really get anywhere, since for the scanner to work you need to set the squelch in order to switch between frequencies, but if you're aiming for a weak signal, it will never be heard if your local FM broadcasters are belting away 24 hours a day.

So, instead I'm scanning each frequency between 87 MHz and 109 MHz, every 10 kHz, for 10 seconds, to see if there's any RDS data to be heard. I send that to a file and when I feel the urge, I can go check to see what I've heard.

I haven't yet put this up on GitHub because I'm considering making it a contribution to the "redsea" project instead of a project of my own.

Now, at this point you might wonder what all the fuss is about. Well, the same method could be used to decode your local amateur repeater idents, or the NCDXF beacons, or any other kind of interesting information. I saw one user link "rtl_fm" to "multimon-ng", a tool I've spoken about before.

You should also check out Oona's website, windytan.com, there's a whole range of signal processing stories to be found, including dealing with flutter distortion on Steamboat Willie and a very cool spiral spectrogram.

I'll leave you with one question. Why haven't you installed Linux yet?

I'm Onno VK6FLAB

-5

Now here's some serious signal processing happening!

15
15
submitted 2 weeks ago by vk6flab@lemmy.radio to c/opensource@lemmy.ml

Anyone know of any scriptable asynchronous communication tools?

The closest so-far appears to be Kermit. It's been around since CP/M, but apparently there's still no centralised language reference and the syntax predates Perl.

-1

Some life lessons require additional reinforcement from time to time. This week I was strongly encouraged to remember a lesson that can be summarised as: "A place for everything and everything in its place." It was first uttered like that to me a quarter of a century ago by a client who used it frequently around their staff.

It means that all the stuff that fills up the space around you, in this case, physical stuff, needs to have a specific home and if you're not actively using it, that is where it should be. This is useful in a context where you have lots of little things that you need from time-to-time, or if you have several people dependent on the availability of a single thing, like say the labelling machine used to tag equipment.

The other day an incident involving a tiny tablet that went flying across the kitchen bench, bounced over the edge and vanished, not helped by the fact that taking the tablet was time sensitive and the fact that the vacuum cleaner was right there - no the tablet was not inside, I checked. I walked around the bench to the other side and started rolling on the ground with the aid of the torch on my phone. Ten minutes in, still nothing. I remembered that my go-bag has a torch, so I went to get it from its place.

One problem, it wasn't there. I turned the bag upside down and went through it. Nope, no torch. That's two things that vanished. Neither has resurfaced at this point. I went to the chemist to get another tablet and took it 40 minutes late.

The torch however was not so easy to resolve.

My, what I call go-bag, has a bunch of life affirming essentials. It started pretty soon after becoming a radio amateur. It has two jumpers, long-leg underwear, an under shirt, a towel and a microfibre cloth, leather gloves, mosquito net, medication, band-aids, toilet paper, soap and some empty bags. It also has a torch, well, not right now it doesn't.

After failing on my mission to locate the torch, I started stuffing the contents of my go-bag, straight back into its bag, only to realise that I wasn't helping future me. I stopped, pulled everything back out and started folding everything neatly. Then I repacked the bag.

I've put in a stand-by torch, in Dutch they're called a "knijpkat", or a mechanically operated torch. You squeeze it in your hand and in doing so you move a dynamo that charges either a battery or a capacitor. It's called a "pinch cat" because it sounds a little like that. The light is fine for getting around in the dark, but you wouldn't mistake it for a super bright, eyeball burning, LED torch.

In case you're wondering why I'm going into such detail about this, it's because you never know when you need something. It might be urgent, or it might not be. Having your stuff organised in such a way that you can find it, can sometimes be the difference between life and death.

Now I get it. Not everyone works like this. I have for decades had a system on my desk where I know where all the bits of paper are and it's not helpful if someone cleans it up, because at that point I have no reference to anything and I will have to go through the whole box of things to find what I need.

When my partner and I travelled around Australia in an Iveco Daily stuffed to the gunnels with electronics equipment, clothes, food, camping gear, a two metre satellite dish and plenty of other things, I had a system that involved four filing cabinets bolted into the van, combined with a dozen or more crates, metal hooks, straps and a safe. I was forever putting things away in the exact same place, each time.

It's not a process that comes naturally to everyone and so we settled on a process where I would pack the van so I could lay my hands on anything within seconds, from the socket set to the satellite signal finder, from a clean pair of shorts to a raincoat, from a fuel funnel to a water funnel. Pro-tip, don't mix the two. Tools aside, of course this system also applies to the first aid kit and the fire extinguisher, the fire blanket, band-aids and medication, and in this case a torch.

You might ask how this could apply to amateur radio. Go-bag aside, looking around my radio shack, it has lots of little things, like adaptors, measuring gadgets, chargers, fly leads, microphone clips, coax switches and plenty of other stuff.

If everything in your shack is in use, this isn't an issue, but if you're like me and don't have your NanoVNA, and all the SMA to something adaptors, or plenty of other things lying around for that "just in case" time, then having a place for everything and everything in its place is a very productive way to keep things organised so you don't spend half your life looking for things.

Similarly, if you know where your portable shack is, your battery charger, an emergency antenna, or some other essential item, you'll discover that when it comes down to the pointy end of a situation, this might make a difference.

So, how do you keep your life, and shack, organised and what other processes and methods have you tried?

I'm Onno VK6FLAB

25
submitted 1 month ago* (last edited 1 month ago) by vk6flab@lemmy.radio to c/privacy@lemmy.ml

U2F keys can be purchased online for the price of a cup of coffee. They're being touted as the next best thing in online security authentication.

How do you know that the key that arrives at your doorstep is unique and doesn't produce predictable or known output?

There's plenty of opportunities for this to occur with online repositories with source code and build instructions.

Price of manufacturing is so low that anyone can make a key for a couple of dollars. Sending out the same key to everyone seems like a viable attack vector for anyone who wants to spend some effort into getting access to places protected by a U2F key.

Why, or how, do you trust such a key?

The recent XZ experience shows us that the long game is clearly not an issue for some of this activity.

27
submitted 1 month ago by vk6flab@lemmy.radio to c/jokes@lemmy.world

Genie: There are 3 rules... no wishing for death, no falling in love, no bringing back dead people.

Me: I wish envelopes would moan when you lick them.

Genie: There are 4 rules...

1

By Onno VK6FLAB

Did you know that on the 18th of April, 1925 a group of radio amateurs had a meeting in Paris? During that meeting they formed an organisation that still exists today. Before I get into that, let me share a list of names.

  • Wireless Institute of Australia - Radio Amateurs of Canada - Radio Society of Great Britain - Vereniging voor Experimenteel Radio Onderzoek in Nederland or if you don't speak Dutch, can't imagine why, the Association for Experimental Radio Research in the Netherlands, - Deutscher Amateur Radio Club, I'll let you figure out what that translates to, - American Radio Relay League

Language aside, one of these is not like the other.

Once upon a time, in a land far, far away, at a moment likely before either of us was born, Hiram, wanted to send a message from his amateur station in Hartford to a friend in Springfield. That's 26 miles, or less than half an hour up the road via I-91.

One minor problem.

At the time, in 1914, using amateur radio for anything beyond 20 miles or so was considered a miracle, so Hiram asked a mate at the halfway point in Windsor Locks to relay a message on his behalf. Soon after he convinced his local radio club in Hartford that building an organised network of stations to relay amateur radio messages was worth doing and the American Radio Relay League was born. Co-founded with radio experimenter Clarence Tuska, Hiram Percy Maxim became its first President. He held many callsigns, most recently W1AW.

At the time, longwave, the longer the better, was considered the pinnacle of communication technology. The airwaves were becoming crowded, so amateurs, in search of more space and always up for a challenge, started experimenting at the edges. The shortest wavelength available to amateurs at the time was the 200m band, or 1,500 kHz. In December 1921 the first successful transatlantic transmissions were achieved. Hundreds of North American amateurs were heard across Europe on 200m and several were heard in reply.

In a dance that continues to this day, new technology replacing old, spark gap transmitters were replaced by vacuum tubes and using those amateurs were able to use even shorter wavelengths. While technically illegal to operate on higher frequencies, the authorities put their fingers in their ears and let those crazy amateurs play on those useless bands.

This is a world without international prefixes, no VK, PA or G stations, so amateurs were forced to come up with their own system to indicate the continent and country.

This was clearly organised chaos at the edges of legality, in many countries amateur radio operation was actively discouraged or even illegal. Soon the same person who came up with the notion of the ARRL led the way and organised a meeting in Paris. That meeting, on the 18th of April, 1925 marks the forming of the IARU, the International Amateur Radio Union and as I said, it exists today.

That date, the 18th of April is globally, well at least in the amateur radio community, uh, well, small pockets of the amateur radio community, known as World Amateur Radio Day.

2024 marks the beginning of a year of celebration for the centenary of the organisation that brought together this global rag-tag group of enthusiast experimenters that we fondly refer to as our community.

The IARU theme for this year is: "A Century of Connections: Celebrating 100 years of Amateur Radio Innovation, Community, and Advocacy" and you're invited.

So, what types of activities are you planning, what kind of celebration do you have in mind, and who is bringing the birthday cake?

I'm Onno VK6FLAB

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