vk6flab

Building a shack makes a number of assumptions about your situation and to make it abundantly clear, it's not the only way to enjoy the hobby of amateur radio. Visiting clubs locally and remotely, being a member of a club, visiting other amateurs, setting up your station in a suitcase or a backpack, on a bicycle, in a car, on a bus, or in a boat are some of the many other avenues open to you.

That said, there is something magical about building your own shack. It has the ability to transform your hobby and if you have the opportunity, I can highly recommend it and I'd like to encourage you to consider the notion.

As I've said previously, there is plenty of exploration and learning associated with putting one together. After you've spent some time reflecting, planning, designing, sourcing, building and testing the environment where you do amateur radio, you're likely to reach a point where you'll refer to that space as "your shack". You might even come to think of it as your shack, rather than a collection of trade offs that you've constructed in the best way you know how.

Inevitably, you'll wonder what to do next.

Several things come to mind. Creature comforts is probably the most obvious, a push to talk foot pedal, or a desk microphone, either on a stand or hanging from a boom, an audio mixer, a couch, a soldering station, a microwave oven, a fan, or air conditioning, in other words, plenty of opportunities for improvement and enhancement.

Then there's computing, something that might interest you, or not. It offers the ability to explore a whole different side of amateur radio, from logging through to digital modes, from weak signal propagation to tracking satellites, the possibilities are endless.

Your shack is also potentially a communal place where you can meet with your friends to share the experience.

It's a place for contemplation, for relaxation, for "being" an amateur. All of it is open to you as possibility, an excuse to improve and enhance.

The thing is, that too will come to a point of, let's call it "completion", and you're left with more questions.

Amateur radio is inherently experimental in nature, that's the whole point of the pursuit. Your licence gave you access to the playground, your shack is that playground. Now it's up to you to play.

Of course what playing looks like is unique to you. Over the past 15 years I've been describing what playing looks like to me, and from the over 3 million downloads last year from my website alone, not to mention the newsletters, rebroadcasts, podcast inclusions, other streaming services, news reports, social media and messages I've received, they've encouraged you to explore and investigate this wondrous activity.

The point is, the shack you just completed isn't finished and hopefully it never will be. Whichever one it is, the first one, the one after that or the next one, your shack is a place where you can experiment, learn, discover, test, fail, succeed, challenge and enjoy the hobby of amateur radio. It's not the only place where you'll find this hobby, but it's your place.

So, have at it.

I'm Onno VK6FLAB

During the week I watched the World Economic Forum speech by Canadian Prime Minister Mark Carney. It was inspired and it made me wonder who represented Australia at that forum using duckduckgo. Their Assumed Intelligence "helped" answer the question.

Apparently here in Australia, we have a new Prime Minister now.

Note that I still don't know who, if anyone from Australia was representing us, but at least your Prime Minister spoke his mind.

PS. I have no idea about the level of approval or not of the Canadian Prime Minister and I don't want to presume or go beyond the observation that AI is nothing more than an autocorrect Ponzi scheme on steroids, funny at times, but too often .. disturbing if not outright dangerous.

Your fellow globe traveller, this one based in Western Australia.

73 de Onno VK6FLAB

cross-posted from: https://no.lastname.nz/post/2276087

Setting up access to a headless Raspberry Pi is one of those tasks that should take a few minutes, but for some reason always seems to take much longer. The most common method is to configure Wi-Fi access and an SSH service on the Pi before starting it, which can go wrong in many different ways. This author, for example, recently spent a few hours failing to set up a headless Pi on a network secured with Protected EAP, and was eventually driven to using SSH over Bluetooth. This could thankfully soon be a thing of the past, as [Paul Oberosler] developed a package for SSH over USB, which is included in the latest versions of Raspberry Pi OS.

The idea behind rpi-usb-gadget is that a Raspberry Pi in gadget mode can be plugged into a host machine, which recognizes it as a network adapter. The Pi itself is presented as a host on that network, and the host machine can then SSH into it. Additionally, using Internet Connection Sharing (ICS), the Pi can use the host machine’s internet access. Gadget mode can be enabled and configured from the Raspberry Pi Imager. Setting up ICS is less plug-and-play, since an extra driver needs to be installed on Windows machines. Enabling gadget mode only lets the selected USB port work as a power input and USB network port, not as a host port for other peripherals.

On your amateur radio journey, you'll likely discover that many transceivers run on 13.8 volt DC, give or take. For example my FT-857d requires 13.8 volt plus or minus 15 percent, with a negative ground, and a current draw of 22 ampere, more on that later.

In other words, the power supply needs to be between about 11.7 and 15.9 volts, the same voltage that runs most vehicles with some wiggle room for fluctuating alternator charging cycles.

While some radios will absolutely fit in your car, there's plenty where that just isn't the case, even though they're set-up for a 13.8 volt power supply. You might think of it as an anachronism, a few steps removed from spark gap transmitters, but there's more to the story.

Most residential power grids run on AC power, at varying voltages and frequencies between 50 and 60 Hz. Across the world there's eight different AC voltages in use between 100 and 240 volts. Some countries use more than one combination and I haven't even looked at three phase power. Perhaps 13.8 volt DC isn't looking quite as odd.

With this revelation comes the need to actually have 13.8 volt available in your shack. Converting your grid power to something you can plug your gear into requires some form of transformation, typically achieved with a power supply.

Efficient, cheap and plentiful, the switch mode power supply is the most common. Built to a price, they're also often noisy, not just the fan, but noisy from a radio emissions perspective.

Amateur radio has very sensitive receivers and as a result you can often hear, or see if you have a waterfall display, RF birdies, a sound reminiscent of a budgie whistling, every 100 kHz or so across the whole radio spectrum. Not something most other equipment cares about, so you're often left to fend for yourself in figuring out how to deal with this phenomenon.

There's plenty of filtering techniques and circuits to be found and some of them even work, but for my money, I'd spend it on a power supply that doesn't make noise in the first place.

A regulated power supply maintains a constant output voltage or current, regardless of variations in load or input voltage. An unregulated power supply can wander all over the place.

Adjustable power supplies allow you to set the voltage, amperage, or both, sometimes with knobs, sometimes using external controls.

At this point you might decide that this is all too hard and you want to do away with all this complexity and use a Sealed Lead Acid, or SLA battery, after all, that's what the 13.8 volt is based on, but then you'll need to charge it. Similarly, picking any battery technology requires some form of charging. Another word for charger is: power supply, often a switch mode one, and likely not filtered in any way that matters to you, since batteries, and for that matter solar power inverters, are unlikely to care about RF birdies.

I will make mention of linear power supplies. When I started on this journey, this was the strong recommendation from my peers as the most desirable option. Although they're significantly less efficient than switch mode power supplies, only 30 percent versus better than 80 percent, from an RF perspective, they're extremely quiet.

Of course, the lack of efficiency reveals itself in the form of heat, which necessitates the application of cooling, from a fan, often a very noisy fan.

One potential source of power supply is a computer power supply unit or PSU. Before you go down that route, consider that they're intended for installation inside a case, often generate various voltages at very specific current draws and are not typically known for being RF quiet.

After weighing up all the variables, I chose a laboratory grade switch mode current limiting adjustable power supply. It's set to 13.8 volt and it sits on my desk doing its thing. Rated at 1 to 15 volts at 40 ampere, it's now as old as I am in amateur radio terms, well and truly a teenager, it's also overkill, by quite a margin.

Remember when I mentioned that my FT-857d is rated at drawing 22 ampere? As a QRP or low power station I typically use my transmitter set to 5 watt, but even when others use it at full power, I have never ever seen it draw more than 12 ampere. That's not to say that it can't draw 22, I've just never seen it.

As a benefit of having such a massive overkill in the specifications of my power supply, I can power more than one radio and not notice. Not that they're all transmitting at the same time, or using more than 5 watt, it just doesn't matter.

I previously discussed setting a standard for coax connectors in the shack, the same is true for deciding what to pick for power supply connectors.

In my case I chose Anderson Powerpole connectors. Pins come in 15, 30 and 45 ampere ratings, are genderless and housings are available in many different colours. When I say genderless, it means that you can join two identical connectors.

Within my shack, I use the RACES or ARES Powerpole wiring standard and every single 13.8 volt connection uses it. If I get new gear that uses some other connector, I'll cut the power supply wire in half and terminate both the power supply and the cut off cable using Powerpole connectors. That way my gear will connect to my own power supply and I'll have a universal adaptor cable when I need it.

Over the years I've collected an impressive array of adaptors using this method and it's helped immensely when sharing gear with other amateurs.

Word of warning, make sure you get positive and negative the right way around when you join your Powerpole connectors, and make sure that you have the red and black housings the right way around too, you can thank me later.

If you do this more than a few times, I'd recommend that you spend the money on a proper crimping tool. It makes the experience So. Much. Better.

To avoid many of the pitfalls of interference whilst connecting power and coax to the same radio, try hard to avoid running both in parallel, or worse, joined to each other. Instead, attempt to run them in different directions and only cross at right angles if you have to.

One thing to consider is the ability to switch everything off immediately. To that end I have a power switch on my desk that isolates all power to the equipment.

You'll notice that I have not said anything about grounding or earthing, that's on purpose. Your laws and mine are not the same. Similarly, information you'll find online rarely, if ever, describes the jurisdiction it applies to, so, look at your own rules and implement accordingly.

I'm Onno VK6FLAB

Noise la la la la la hinders if I were a rich man effective a noise annoys an oyster communication but a noisy noise annoys an oyster more.

Or said differently, when you're trying to communicate, something that the hobby of amateur radio does in spades, you'll need to deal with a phenomenon called noise.

This noise comes in different forms, but the effect is the erection of barriers to successful communication. We refer to the impact of noise as a signal to noise ratio or SNR, the signal being the desired information, the noise the undesired interference. Expressed in decibels so you can deal with a massive range using a small number, an SNR greater than 0 dB means that the signal is stronger than the noise.

Building a shack requires that you consider noise in many forms. If you've been a radio amateur for a few moments, your mind is likely to head straight for the hiss, crackle and pop you might hear whilst attempting to communicate on HF, but there's a few other things to discuss.

There's all sorts of electronic noise received by your radio. In addition, there's audio noise picked up by your ears, and often your microphone. Then there's the noise that you produce, either from your transmitter into the rest of the building, or from your mouth or speakers into the ears of the people you share the space with.

Starting with audio, having a space that you can close the door on is a good way to limit the noise coming into and leaving your shack. An alternative is to wear headphones and generate text to speech, or prerecord your voice, ready for a contact, potentially ideal for contesting, not so much for free form discussion. Another consideration is audio from other radios, including those tuned to a local broadcaster, or aviation frequencies. In other words, if you're transmitting with a microphone, make sure that there's no other audio coming through. In some cases it's even illegal to transmit that audio, but in all cases it's noise that makes communication more difficult.

This kind of audio noise mitigation is pretty straightforward.

In stark contrast, achieving the same with electronic noise is pretty much a balancing act between budget and effectiveness.

The impact of noise is inversely proportional to distance. Essentially, the closer it is, the more impact it has. With that in mind, when you start dealing with noise, start nearby and work your way out. As you eliminate the nearby noise, other sources will become apparent.

Without turning this into a noise mitigation class, the process is essentially one of elimination. First locate the noise source, then eliminate it. That's easier said than done.

For example, if the noise source is a power supply sitting on your bench, you can turn it off, except if that power supply is the one powering your radio, so perhaps I should say: "attempt to eliminate it" instead.

There's plenty of ways to have a go at this and volumetric kilotons of content published on the subject, some of it even useful.

In many, but not all cases, noise is an electrical phenomenon that enters via any means possible and you'll need to attempt noise mitigation at multiple points of entry. Obvious sources are the power supply, coax and the antenna connection, the speaker cable, the microphone lead, and if you're using a computer, the USB, serial or Ethernet cable and within the computer itself. Each requiring different approaches.

The obvious one is to disable the noise, that is, turn off the offending device. As I said, that might not be an option, but you can replace noisy gear, or place it further away.

There's isolation, using tools like ferrites and chokes to stop the noise from reaching your radio. Often in the form of a clip-on blob, you'll find these on things like monitor and USB cables. Place the ferrite as close as possible to the input of your radio. If it's loose on the cable, wind it through the ferrite, the tighter the better.

There's software solutions with varying levels of effectiveness. You'll find DSP or Digital Signal Processing knobs and buttons on many radios. They're generally helpful for narrowband repeating noises, like the hum of an electric motor or power supply.

There's tools that attempt to impose a noise on your signal that cancels out the noise, anti-noise, if you like, by receiving the noise, inverting it and adding it to your signal, thus, at least theoretically, eliminating it, noise minus noise is silence. This can take the form of a device for noise coming in from the antenna, but it also applies to things like noise cancelling speakers. In audio this is called active noise cancelling.

There's also a new crop of noise cancelling software, using A.I. or Assumed Intelligence, that captures your signal, attempts to figure out what's noise and what's not, removes the noise and then feeds it back to you. Your Mileage May Vary and if you break it, you get to keep both parts. Consider your privacy and security implications of sending your audio out the door to be processed.

That's not to say that, at least theoretically, effective local Machine Learning models could be created to help with this. I have yet to see one.

At some point you'll hopefully reach a place where the noise inside your shack is no longer an issue. Then you'll discover your noisy neighbours, with solar panel inverters, pool pumps, plasma televisions, broadband modems, kids toys and pretty much anything electronic, purchased with no consideration whatsoever in relation to your hobby.

I'm mentioning this, because more often than not, you'll have little or no control of those devices. You could cultivate your relationship with your neighbours and discuss your situation, but don't expect compliant hardware to magically solve all your issues.

Antenna orientation, horizontal versus vertical might assist, as might placement or distance from the noise source. It's why I suggest that you start this journey with simple antennas, with plenty of room for evaluation and modification to suit the conditions.

All this to point out that once you have the perfect shack, your work is only just beginning, but then I suspect that you've already realised this.

Like antennas, I will note that noise and its elimination is an integral part of this hobby. It's easy to forget that, whilst you're in the middle of a frustrating hunt for a noise source, and if you like you can think of it as ripples or waves on the pond whilst you're casting a fly.

When you discuss this with other amateurs, you'll likely come across terms like QRM and QRN, the last letter describing either Man-made or Natural noise. I'm not sure how helpful the distinction is, but it's there if you need it.

One resource worth mentioning is a website called qrm.guru. It has documented processes and tools to discover where noise is coming from and how to go about dealing with it.

I'm Onno VK6FLAB

Putting your station together is best described as a juggling act, since you'll discover that everything depends on everything else and the more you plan, the more you learn and the more variables become apparent, none more so than with the selection of an antenna.

Antennas are endlessly variable. To give you a taste, imagine a loop of wire, shaped like a circle. As you stretch the circle, it becomes an oval, if you pull on four corners, it's a square, pull it tight between two points and it more or less becomes a single wire. In other words, one piece of wire can essentially make an infinite number of antennas, and we haven't even varied the material, length, thickness or coating.

So, to discuss antennas is to embark on a lifelong journey of exploration and me telling you to get one over another is not going to help, instead I'd like to discuss some considerations that you might not have encountered.

The obvious issue of space is generally the first consideration. Then there's the neighbours and their sense of aesthetics, or lack thereof. There's local laws to abide by and sometimes permissions and permit requirements, though in many cases it seems that seeking forgiveness is a quicker route to success. Your Mileage May Vary. Talk to your local amateur club.

There's the property owner to consider. If that's you, great, drill away, if not, you will need to tailor your antenna selection to the amount of renovations required.

If you live in a restricted location where there are all manner of rules about the things that you cannot do, you might need to think carefully about your options. Stealthy antennas are a thing. As I've said previously, inside your roof might be an option, but there are others.

Some examples to consider.

If there's a TV aerial on your roof, will that look similar to a 70cm Yagi, or could it hide a 2m vertical? Do you have a metal gutter which might act as an antenna, or could you use Christmas light clips to hang a wire antenna from your gutters? Could you hide a vertical in a plastic down-pipe? Could you dangle a ladder-line antenna out a window at night, or use thin wire to hold up your plants while hiding your antenna in the garden, or can you use a beverage antenna that's lying on the ground, or hidden under the fence capping? Could you tune up your fence for that matter?

In other ways to make your hobby look invisible in plain sight, could you use an antenna that looks like a roof vent, or if you're into moon bounce, could you repurpose a satellite dish? Could you make your outdoor washing line into an antenna or add a flagpole vertical antenna that also happens to soothe your vexillology sensibilities?

While we're talking stealth, you can paint your antenna to match the decor.

To get your antenna up in the air, could you use a length of wood, a pool cleaning or painters pole, strapped to your pergola, gazebo, balcony railing, or some other existing structure? Can you use the edging of a shade sail, professionally installed, it comes complete with mounting points.

It doesn't stop there, I've heard of several amateurs who managed to park a sailboat, with the mast up, in their driveway without ever once floating it in a nearby body of water.

Of course this is not exhaustive, nor is it meant to be, it's really a trigger to think about some options you might not have discovered. In other words, if you need stealth, you can be creative, rather than buy an antenna off the shelf.

Speaking of buying off the shelf, there's nothing quite like buying a wonderful antenna, the answer to all your questions, only to discover that it needs tuning and tweaking, to the point where you might spend a year getting familiar with all its quirks. That's not to discourage you from picking that path, just to warn you that there is no such thing as the perfect antenna.

If you are less space restricted, building a tower or a mast, the difference being that a tower stands all by itself, like the one in Paris, a mast needs guy-wires to keep it up. You'll likely need to consider failure, engineering standards and concrete, not to mention maintenance.

So, how do you go about selecting the perfect antenna to suit your needs?

In the same way that a magician pulls a rabbit from a hat.

In other words, there's a trick.

It's pretty simple, start small.

With that I mean, start with a simple wire antenna. It will achieve a number of things that only experience will give you.

For starters, it will prove that your shack works. As-in, end-to-end. That might not sound like a big deal, but there are many different moving parts in building a successful shack, making your first contact is going to be a milestone worth logging, more on that another day.

While making your first contact is momentous, getting an antenna in the air will also allow you to hear what your neighbourhood sounds like. Is it completely RF quiet, in which case, where do you live and do you have a spare bedroom?

The reality is, for most of us, local RF noise is the norm when setting up your station. Noise is a whole other topic and I'll get into that next time.

I haven't said anything at this point about your living circumstances, but it should be obvious that anyone you're living with needs to be on-board with your adventures, so discuss your plans and concerns.

I'm Onno VK6FLAB

When you start the process of getting your hobby off the ground, either for the first time, or after a hiatus, you might be left with the impression that the only way to "do amateur radio" is to have a shack, a place where you can set-up your gear, and connected to that gear using coax, one or more antennas. While that's a common scenario, it's not the only one at your disposal. We are after all in the game of communication and over the past few decades options have exploded.

Starting closest to the traditional radio, coax and antenna, is to consider indoor antennas. There's many to choose from. You can install one in the same room as your shack, or, you can build your antennas in the roof space, either way, invisible from the outside can sometimes be a requirement. Stealth is a topic all its own, and no doubt we'll get to that another time.

A word of caution. If you do have an indoor antenna and associated coax, consider your transmitter power levels, since it's likely that given the close proximity, you'll exceed emissions safety standards, or you'll cause harm to other electronic equipment in the building. QRP or low power is a good way to go if this is something you're considering.

If we step away from a traditional radio, coax, antenna configuration, you can build your shack in other ways too.

For example, you can use a local repeater which you might trigger from a local handheld radio. Often dismissed as being for local communications only, there are thousands of repeaters across the globe offering a variety of bands, frequencies and modes. Often you can access a local repeater that can be connected to a remote one using a bewildering array of technologies, some using the internet, some using traditional RF. You'll find repeaters on 10m, 6m, 2m, 70cm and 23cm.

There's nothing stopping you making your own repeater. You don't even need to go through the effort of making it completely standalone, for example, my Yaesu FT-857d has a detachable face-plate or head, connected to the main body by a short cable. There are plenty of other radios with a similar configuration.

Presumably designed for the installation in a vehicle, where the head needs to be near the driver and there's unlikely to be space for the body, you can run a longer cable from the head to the body and install it somewhere more convenient. In my case it was bolted underneath the removable floor into the boot next to the spare tyre.

There's several solutions that replace the connecting cable with an internet connection.

Now, that internet connection can be across the room, from inside your shack to your garage, or between your shack and a remote hill where you have permission to put up a bit of gear. In fact, the same type of setup can be used to connect to shared radios, and companies like Elecraft, Flex Radio and ICOM make specific remote heads that can operate remote radio equipment, marketed as RF decks, without needing to install and maintain computers at either end, but more often than not, this equipment is brand or model specific.

Which raises another option.

You can connect to remote equipment across the internet using your computer, which means that your shack might be a computer, a laptop, or a mobile phone and your gear might be in a different country.

Many radio clubs have discovered that their often extensive radio shack is virtually unused during the week, and have installed remote equipment to allow you as a member to connect, sometimes as part of your membership, sometimes with an extra fee, since there are costs associated with setting this up and keeping it running.

At some point you're going to discuss this with other amateurs and you're potentially going to hear someone tell you that this is not "real radio".

Considering over a century of radio evolution, from spark-gap through valves, transistors, integrated circuits and software defined radio, where exactly is the "real radio" line drawn?

Is using WSPR, RTTY, FT8, Hellschreiber, Olivia, SSTV, PSK31, Domino, MFSK and thousands of other digital modes "real radio"? If the answer to that is an emphatic "yes", then ask yourself, how do you actually use those modes?

The answer looks suspiciously like a computer running digital mode software, either connected to a physical radio in the same room, or connected to one across the internet.

In other words, with the proliferation of communication alternatives, amateur radio is evolving. No doubt it will evolve further.

So, today, a perfectly viable, and some might say, modern, amateur radio shack might not actually have any traditional RF based radio gear, though perhaps a hand-held might be something to consider when you next treat yourself, not because without it you're not a real amateur, but because it opens your world to other means of communication, something which I think is perhaps even more important than building the perfect shack.

In other words, you are not required to have a shack to be a radio amateur, it's just that it brings with it another dimension of engagement and activity. Speaking from personal experience, I miss my functional shack, but it's evolving, so there's that.

Next time I'll take a look at antennas, stealthy or otherwise.

I'm Onno VK6FLAB

Such antennas are primarily to be used in person-portable / rucksack-portable activations of parks, hills and mountains, islands and lighthouses in the various amateur radio outdoor award schemes. They would also be ideal for Field-Day operations, either as the main antenna for a single-op entry, or as an alternative antenna for multi-op entries. Of course, the same antenna designs can also be used at a home QTH - just use more substantial fittings and support structures.

The tools included in each designer page enable displays of radiation patterns, VSWR curves, antenna current diagrams, and Smith charts - all calculated and displayed dynamically for the antenna you design. No other website offers such an extensive set of tools to check your antenna design.