Foundations of Amateur Radio

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Do we really understand our hobby? Jan 01, 2017

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Foundations of Amateur Radio

Today I was going to talk to you about Grid Dip Oscillators. Some research later I realised that I don't yet understand the topic enough to explain it to myself, let alone explain it to you. I then set my sights on a simpler thing, an SWR Meter.

Pretty standard fare in a radio shack. You plug it in and off you go, nothing to it.

So I then set about learning how this actually works. As you know, if it's written on the Internet, it must be true, and in this case, there must be a thousand different explanations and ways that this common black box works in your shack. Since I found so many different explanations that made me recall a quote:

"You do not really understand something unless you can explain it to your grandmother."

So, at this point I should sit down and explain it to you as if you're my grandmother, right?

Unfortunately I'm not yet at that level of understanding, so I'll not add to the noise of explanation until such time as I do understand it. Instead I'm going to take a left turn and observe that Amateur Radio is full of explanations. Some of them great, many of them horrendous.

I see Amateurs on-line arguing about how something works and then I hear them on-air doing more of the same.

It occurs to me that where ever there is argument about how something works there is one of two things going on, lack of knowledge or lack of understanding.

I'm not saying that every Amateur doesn't understand, I'm wondering if it's possible that our collective understanding of how our hobby works appears to be lacking in scientific rigour and that it's incomplete. I'm wondering how much of our hobby is actually understood and documented.

While I'm here, I should point out that taking observations of a phenomenon isn't an explanation of how it works. The observations will get you places, but the unexpected or unobserved might get you killed along the way.

I've said in the past that this hobby is like Magic and I still think that. The more I learn and understand about it, the more Magic comes in to play. This is what keeps drawing me back to this wonderful world of Amateur Radio.

While I was searching for my SWR explanation I came across this little gem which speaks to me greatly and goes a long way to explaining why some of our hobby is so misunderstood:

"the reason that your friends and ours cannot understand mathematics is not because they have no head for figures, but because they are unable to achieve the degree of concentration required to follow a moderately involved sequence of inferences"

So, next time you sit down to explain how something works, bear that in mind, since following along a string of things that lead to an explanation might not be something your, or my, friends are willing to put up with.

I wish I'd seen that quote before I attempted to explain why I had several antennas on the roof and couldn't just have one.

Still learning...

I'm Onno VK6FLAB

SOTA goat adventures ... Dec 25, 2016

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Foundations of Amateur Radio

Last week I went on an adventure and came home with an experience. I've been wanting to go out and play radio for a while. Work has been spectacularly unhelpful in making time available to achieve this, not to mention the 17 million other things vying for my undivided attention.

Last week the planets aligned and my outing came to pass.

I'd set my sights on doing a SOTA activation. If you're not familiar with that, SOTA is an acronym for Summits On The Air and the aim is to get to the top of a mountain and make contacts from there. I've previously been under the tutelage and presence of some very experienced SOTA hams and during a conference in Canberra last year I managed to activate several summits with others.

I even managed to survive walking up one peak on my own, using my hand-held to make some contacts. I use the word survive in less than ironic terms because I relied on Google Maps to navigate me up to the peak and for reasons best known to Google, it walked me up the side of the peak that didn't actually have a track, even though the map was adamant that I should follow the path. Many, many hours later, not properly dressed, not enough food, weather coming in, batteries running low, I managed to get back down safely and hobbled to a taxi who brought me back to my hotel. It was memorable, but not for the right reasons and it didn't involve HF communications and at the moment I'm struggling to recall if I actually logged those contacts. That will be a job for another day.

Anyway, as I said, the planets aligned and I had a day to myself, access to the car, a charged radio battery pack, a working antenna and a map that worked. Mind you, I spent an hour fighting technology. First to register on the SOTA web-site, then to activate the software on my phone, then to get Google Maps to actually navigate me to the peak and for it to download the off-line maps, so I could navigate whilst out of mobile phone range. Lesson learned, plan to do the technology before the day.

So, I set off an hour later than planned, but I was finally on my way. Google Maps again let me down by navigating a different route than I wanted, since I had the choice of more or less dirt road and I wanted less. Google picked the other one, even though I pointed it at the one I wanted. Another lesson learned, make sure that you add markers to your route before Google Maps starts you on your way, since there is no changing it once you're driving.

After an hour and a bit I arrived at the top of the peak. If you're interested, it was Mount Dale, or SOTA peak VK6/SW-036, but before you go looking for my log, stick around, there's more to the story.

So, I set-up my antenna, a multi-tap Outbacker and set it to 40m. I appeared to have mobile phone coverage, so I added my spot to the SOTA-watch website and started calling CQ. I managed my first contact within 8 minutes of my advertised time start time, so I was pretty chuffed.

For the next few hours on 40m and 15m I managed contacts with 23 stations. The biggest distance I managed was 5353 km, or 1071 km per Watt. Not bad for a vertical antenna mounted to my car.

I did some experiments along the way with turning my car around, getting better and worse signals, but overall it was great.

I had a little play with 2m, but didn't manage anything other than talking on the local repeater, which is located 24 kilometres away and about 250 meters lower down. One friend suggested that there was a satellite pass coming over later in the day, but by the time I'd been there for four hours I was cooked. It wasn't spectacularly hot or anything, but it was time to go. No satellite this time, but something to add to my list of things to check.

I came home and basked in the enjoyment of having gone out and made contacts, more than I'd managed for most of the year. Very satisfied.

The next morning I found an email from the SOTA manager in VK6 who asked me about my operating environment. After some back and forth it was determined that I should have read the rules before going on my trip. If I had I'd have known that I couldn't operate from within my car, nor could I operate with anything attached to the car. In later discussions one person said that the guideline they used was that if someone drove the car away, would they still be able to operate their station. It seems even shade from the car is frowned upon. So, another lesson learned, read the manual before going outside.

In my discussions it emerged that my trek did qualify for WWFF, or World Wide Flora and Fauna where the rules are different. Of course I've not yet read those rules either, but you know, radio. I should point out that the local Flora and Fauna group is called VKFF.

So.

I swallowed my pride, sent an email to the SOTA email list and posted on the SOTA group to tell my contacts that I wasn't able to submit my contacts as valid SOTA contacts, but that I would be cherishing their contact in my log.

I've not yet sent off my log to the local WWFF coordinator, work has managed to stymie that effort, but I have the log and I'll send it off when I have a spare hour to enter the contacts into a computer and format them as required.

So, from a lessons learned perspective I managed to get to the top, set-up my radio and make contacts. That's a great outcome. I have been out when that didn't happen.

I also learned that Google Maps, something which I use almost daily, is still trying to kill me, it's just being more subtle about it than I would like. I'm sure that there's a reddit writing prompt in there somewhere. Perhaps I'll write it in my munificent spare time.

I should read the rules for both SOTA and WWFF and I need to figure out how I'm going to be portable with my radio bolted into my car. I really don't fancy pulling it out and I'm not in any financial position to go out and purchase another radio, though if you're feeling inclined, you're welcome to make a donation to my benevolent fund - the Donate button is on the podcast website.

On a more serious note, I did receive an email while I was on the top of Mount Dale from a listener who was freaking out that they were listening to me on last week's podcast and saw my callsign on the SOTA cluster, so I replied by telling Brian, AF7MD, that I was still on the mountain. He hasn't replied yet. I hope he's OK.

I did get lots of other emails from well wishers for my First Solo SOTA effort, so thank you for your messages of support. Sorry I let the side down by making an invalid activation as my first effort.

So, I think the message should be that SOTA can be fun, it can be rewarding and you can make contacts with 5 Watts, but you need to read the rules and prepare the day before you plan your outing.

I'm Onno VK6FLAB, not quite a goat yet.

Passion and Politics Dec 18, 2016

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Foundations of Amateur Radio

Today I want to talk about Politics. I can hear you groan from here, so hold your horses, stow your tar and feathers and put your pitchfork back in the barn.

Amateur Radio is a hobby. It's to do with electronics and physics and the ionosphere and other cool stuff. Some people call Amateur Radio a thousand hobbies in one and that's a pretty good description.

Underlying Amateur Radio are the people. Those who have spent their time studying, learning new skills, doing tests, passing exams, as well as people who are interested bystanders, not necessarily licensed, but drawn towards the bounty that Amateur Radio as a hobby represents.

An interesting phenomenon among people is their varying level of passion. Some people are passionate about their dog, others about their children, others are passionate about cars, or baking, or in our case, passionate about Amateur Radio.

Passion has been explained to me once as a "big elephant". You sit on its back and it takes you where you want to go. Gentle nudging makes the elephant change direction, but if it gets excitable or startled, it'll go where ever it wants and all you can do is be a passenger and hold on tight.

If you mix passion and Amateur Radio, there are times when that will result in heated discussion about the merits or pitfalls of a particular radio, an antenna or some other aspect of the hobby.

If you group people together into radio clubs then those clubs are made of passionate individuals who come together to promote the objects of their club. As people group and discuss, opinions differ, goals morph and change and aims and objectives are blurred.

Before long, you get special interest groups, proponents and opponents, elections, board meetings, stoushes, mis-management, legal action and the whole gamut of life.

To complicate matters, Amateur Radio uses a public resource, radio spectrum. This is generally managed and maintained by a regulator, which in turn is generally managed by, politicians.

What this means is that as a Radio Amateur you should not be surprised to learn that politics plays a part just as it does in the rest of society.

I can still hear you muttering from here. My In-Box hasn't yet seen any derisive emails, but I can picture their arrival.

What does this all mean?

It means that Amateur Radio is not one thing. It never has been and never will be. For each individual there is a personal path to find and a journey to travel. For some this means that they'll become the Contester of the Year, for others it means that they'll invent a new gadget, others will use Amateur Radio as an excuse to travel the globe and others will use it to be the big cheese in their club.

Your role is simple.

Remember that this is a Hobby. That it's your hobby and that you have as much say in it as the next person.

Remember also that this Hobby exists because we've been given access to a public resource and it's our responsibility as Amateurs to conduct ourselves in a manner that befits that public trust.

I'm Onno VK6FLAB

Coax vertical dipole and other musings ... Dec 11, 2016

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Foundations of Amateur Radio

The other day I celebrated my sixth birthday, no not that one, the one that reminds me when I first became licensed as a Radio Amateur. It caused me to reflect on what I've done with my license and what I've learned and where I'm heading.

A recurring theme in my Amateur life is one of upgrading. Not a month goes by when someone makes a comment about my license status. As you might know, I hold the entry level license in Australia, the Foundation License as it's called. Other countries call theirs different things, but the aim of this license type is to introduce new entrants into the hobby and for me it's done that in spades.

If you've listened to some of my previous mutterings and musings, or if you've listened to all of them, heading for 300 now, you'll have noticed that it's rare that I'm not talking about something I learned, something new, or something that interests me that I've found and I want to share with the community.

This quest for knowledge, learning and curiosity is something that I've always had and I'm sure I'm not alone with those traits. It occurred to me that my newly minted Amateur License achieved exactly what it intended to, Introduce me to Amateur Radio. It did more than that. It set me on a path that I'm travelling down today where I'm learning a new thing most weeks and telling others about it.

I don't yet fully grasp the difference between an NPN and a PNP transistor, nor do I understand the workings of a Valve to the point where I can explain it to you, but the truth of the matter is that I haven't had the need to, or at this stage the curiosity to. That's not to say that a day will come when I do want to know.

So here's the thing.

Would you rather I have the highest level of license, having passed my test, cramming for my exam, guessing answers on a multiple-choice form, or would it be better if I came to know and understand the body of work that makes up the foundations of our hobby? As an aside, I have taken a mock test at some point. If I recall, I managed a score of 75% or so, might have been higher, but it outlined the areas of knowledge that I don't have at this time and that was why I took it in the first place.

There are Amateurs who pass tests and then there are Amateurs who learn.

One final comment about upgrading. When was the last time you upgraded your car license to the next level, say rally driver, or Formula-1 driver? When was the last time you got called out on not having upgraded and admonished for being a lowly car driver?

Onto Amateur stuff.

First of all, the wheel bearing has gone to a better place. It drove away on a big blue truck on Wednesday morning and is no longer. So sad.

In antenna news, you may recall my experiences with the installation and tuning of an antenna for a friend of mine. I made all manner of what some would call outlandish statements, one Amateur all but called me a liar and accused me of making it all up to promote my podcast. All this excitement because I dared query the documentation of an Antenna. I've reached out to the manufacturer, but I've not yet received a response.

I'm told that my hunch that this was a vertical dipole was correct. That in itself is curious since I've been experimenting with a vertical dipole made from coax, not enough to talk about success yet, but enough to be told that it will never work. Gotta love the doubters. As I suspected, the cut-off piece of inner coax, if you recall, the one that was a centimetre or so too long, is half of a capacitor, the other half is in the base of the antenna.

Note that all this is based on what I've been told by a fellow amateur, and I'm looking forward to hearing from the manufacturer what they have to say.

So, my vertical coax antenna idea started off with the idea that I wanted to use a vertical dipole for working portable. I realised that some of the designs I've seen knocking around the 'net are cutting off long chunks of shield, or folding it back, or doing all manner of funky things to a piece of coax. I wondered what would happen if I took a piece of wire, cut it to the length of one half of a dipole, attached a banana-plug to it and stuck it on the end of a piece of coax.

One half of the antenna would be the wire, the other half would be the shield of the coax.

If I could come up with something like a choke that would stop RF travelling all the way back to my radio, I might have myself a vertical dipole with the benefit of not having to cut up coax, no extra connectors and if I made it possible for the choke to slide up and down, my antenna would be simple to transform into something for any band.

As I said, I'm not yet at the success stage. I did some testing with something called an ugly balun, but it's pretty clunky and results are mixed. I tried ferrite-clip-on-beads, but they didn't seem to do the trick - though that could have be the nature of the particular clip-on's that I had at the time.

When I have some more play time free, I'll have another crack at it, since it seems promising and if there are people selling vertical dipoles with curious matching networks at the base, there's hope for me yet.

I'm Onno VK6FLAB

Manufacturer drivel and antennas ... Dec 04, 2016

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Foundations of Amateur Radio

Let me start completely off-topic today with a thank you for emails and other expressions of concern regarding the demise of the bearing last week from my messy desk. I did not loose my marbles, other than the ball bearings in the disposed item and my sanity is as intact as it ever was. I was also asked for photos of the messy desk and as a concession to that I'll use a photo of the ball bearing for the podcast edition this week.

How am I able to produce a photo of the disposed ball bearing? Truth be told, it's in the bin, the bin is in my office, but it wasn't emptied last week, since there was so little inside, so the ball bearing lives - until Tuesday when the bin will surely be emptied.

Now, on to Amateur Radio matters, since that's why I'm here, though based on your emails, I'm not quite yet sure why you're here.

Yesterday a good friend of mine, who tragically has yet to see the light and become a licensed Amateur came to me with a non-functioning antenna. He had purchased a so-called "Ground Independent Monopole" suitable for 380 to 520 MHz. You get no points for guessing that this was to be used for a CB installation on his vehicle.

When you read the accompanying material, this magical antenna has a 4 dB improvement when compared to a 3 wave whip in the centre of a metal roof. But then when you look at the foot note, it talks about a 4 dB improvement over a 1/4 wave whip, but pattern tests only deliver a 2 to 2.5dB actual gain.

I can hear you groaning from here. It leads me to several observations.

As a licensed amateur you should be able to already spot holes as wide as a semi-trailer in those few statements. As amateurs we're often dismissive of the CB community, but how can they be held to account if manufacturers publish what looks to me like drivel of the highest order.

The design itself is curious. There appears to be a loading coil in the base, the centre of the coax is trimmed to a specified length and inserted through the coil and electrical continuity exists between the radiating element and the coax shield.

After spending some time trouble-shooting the installation I determined that the PL259 connector at the end wasn't actually soldered to the coax, so we fixed that. Using my antenna analyser we trimmed the vertical as specified, a couple of millimetres at a time, but it wasn't setting the world on fire with the updated SWR charts I was generating.

We stopped trimming when we got close, since cutting off length is easy, cutting on length not so much.

I then re-read the instructions and queried the length of the trimmed bit of inner coax that was inserted into the loading coil and found out that it was about a centimetre too long. Fingers crossed we trimmed that to length and the SWR chart improved. It still didn't set the world on fire, but at least the SWR wasn't 8 to 1 on CB Channel 40.

Of course I've urged my friend to get an Amateur License, but that's ultimately their own choice.

What I took away from the experience is that even a very basic Amateur License like the one I hold is sufficient to understand better what is going on and to be able to begin the process of trouble-shooting antenna installations.

I thought I understood that this antenna was basically a vertical dipole, but at the moment I'm not sure and I'm wondering if the loading coil is actually a matching circuit and I wonder why the coax shield and the radiator are connected to each other.

I'm sure the antenna is designed with the best intentions and I'm moderately confident that it works as intended. Now all we need to do is train the marketing department to talk to the engineering department before publishing their materials.

For me the take-away is two fold. Don't blame a CB-er for their lack of knowledge, sometimes the manufacturer is to blame. The other take-away is that with a basic understanding of Amateur Radio you can help your fellow radio operator.

Now, where on my desk is that thing I was looking for?

I'm Onno VK6FLAB

Messy shacks are the way we do things around here. Nov 27, 2016

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Foundations of Amateur Radio

In my time as a member of the radio community I've been in around 30 different shacks and a similar amount of camp-out style activations. I've operated at least a hundred different radio set-ups with different operating styles, logging systems and power sources. I wouldn't say that I was particularly experienced, but I've seen enough to make some observations.

My first observation is that radio shacks and set-ups tend to be messy. It's not unusual to see several radios, antenna tuners, amplifiers, switches, computers, power supplies, soldering iron and accumulated cruft in the form of resistors, wires, spare antennas, connectors, screws, knobs and globs of solder, all vying for space on the same bench at the same time.

I'm looking at my own desk right now and I can count a hundred different objects within 60 seconds with no effort what-so-ever, and that's on a desk that's barely larger than a square meter in size. I'm not particularly messy in the scheme of things. There's no food on this desk - other than the cup of coffee I've just made and there's no globs of solder or other sticky things like oil and glue, but still.

One of my friends remarked the other day that no matter how much space we have, we always seem to run out. He wondered why. At the time, my reply was something along the lines of: "Well, it's for the same reason as your bank-account never has enough money in it."

While that observation is probably valid, I'd like to point out some side effects of a messy desk.

If your intent is to operate the radio and get on air to make noise, there needs to be a working station. You need to be able to test it without having to move stuff around and fault finding needs to be part of the way the thing is set-up.

One station I visited had solved this problem by moving their operating station away from the wall so they had two access points. The front where you operate the station and the back where you test it. That way you get to have your cake and eat it too. The set-up worked really well.

Picture a few racks with gear, an operating desk arranged in an L-shape, but moved away from the wall, rather than pushed into the corner. Space limitations prevented you from walking all the way around it, but you could get to all but one side of one rack.

All this was arranged into the space of a standard spare bedroom, pretty much the same as most shack's I've visited. I find myself looking around my own environment with this front-and-rear idea in mind and I'm having a think about how I might apply it.

Another observation is that we never ever throw anything away, ever. I have seen antenna projects that were doomed to fail from day one, spare screws, bits of wood, drawers and drawers of random electronic components, bits of wire, cut-off connectors, damaged bits of coax, half-wound baluns, empty tubes of silicone, failed micro-switches, bent wave guides, broken windings, arced air-gap capacitors, empty boxes, plastic bags, old radio magazines, all waiting for the day that they become useful, likely never.

I'm not saying that this cruft is never useful. I'm saying that the chances of them being useful is inversely proportional to the amount. That means, the more junk you have, the less useful it is. Perhaps culling is a way to increase the usefulness of what's left. The ultimate example of something like this is a Go-Cart wheel bearing that I have lying on my desk. It's a piece of precision engineering, but it's stuffed. It has completed it's useful service life, was discarded in the dirt and I picked it up, cleaned it, oiled it and now it sits on my desk. It looks great, feels nice to play with, but as objects go, it's one of the least useful items on my desk, otherwise filled with paper, computer gear and radio gear.

I just made the bold step to toss it in the bin. Not yet sure how I feel about it, but I'll try by saying that it's the beginning of making the remaining cruft on my desk more useful.

Perhaps our communal messiness is a thing to do with amateur radio as a hobby, or perhaps we have more than our share of messy members of society. The very nature of our hobby is that we test and trial things whilst doing on-air stuff like making contacts and chatting with friends. Perhaps we should arrange our work-spaces to match.

If you've found a way to make it work for you, please feel free let me know and perhaps send me a picture or two.

I'm Onno VK6FLAB

Amateur Radio Satellites ... more than two in the sky. Nov 20, 2016

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Foundations of Amateur Radio

There are moments in your life when you say to yourself, duh, why didn't I think of this earlier?

I had one of those last week.

As you might recall, I have a hard time using HF communications from my home. There is lots of noise around and I've been going out mobile and portable to make contacts. As satisfying as that is, nothing beats sitting at home in your comfy chair with all the other home amenities.

Ideally I have this notion that I should be able to do my hobby from home and have my cake and eat it too. Turns out, my duh moment was just that.

I speak regularly on the local 2m repeater, in fact I host a weekly net called F-troop that encourages new and returning hams to get on air and make some noise in a friendly environment where no question is too silly and mistakes can be made on-air without subsequent yelling and carrying-on.

So, I have a fully working HF radio at home, but it works just fine on 2m and 70cm.

My duh moment was when I realised that there are a multitude of 2m and 70cm transmitters around that I could add to my tally of things heard and worked. There are websites dedicated to these transmitters and schedules exist to highlight when, how and where these things are.

So, what am I talking about?

The wonderful world of Amateur Radio Satellites.

There are lots around, sending out idents, having uplink and downlink, sending out digital packets, you name it, the wide variety of Amateur Radio in a 90 minute orbit around the planet.

I'll confess that I thought there were one or two doing the rounds, but there are a few more. Just counting the active ones, there are 85 satellites designed to be used by Amateurs at the moment, of course that changes all the time, going up and down as more are launched and others stop responding.

In addition to this collection, there are other things you can listen out for, like weather satellites, the International Space Station and a bunch of other objects.

I came across the N2YO website which shows you what's up in your sky right now, the foot print and direction, when it clears the horizon, in which direction and what the highest elevation is and when it vanishes again, all very helpful in getting half a chance to hear the transmission in the first place.

I've said this before, this hobby is magic. I can't do HF, so now I'm playing with satellites. Looks like I'm going to have to sort out some digital decoding software as well, since many of the satellites have all manner of non-Morse code transmissions, APRS, digital modes, graphics, etc. Lots to learn.

Did I mention that you could do much of this with a hand-held radio? Power is not a problem and an external antenna is likely all you'll need.

By the way, this is what I like about Amateur Radio, there are so many different aspects to this hobby, so much variety, so many things to learn and experience and I have only just scratched the surface.

It bears repeating that a beginner's licence in Amateur Radio gives you access to all this and most of the things I've been talking about since I started talking about the hobby back in 2011. I've been licensed now for a little more than a minute and a half, but I still get a pleasant surprise on a regular basis about the size and scope of my chosen hobby.

There's no excuse, getting bored with Amateur Radio is just not an option.

I'm Onno VK6FLAB

DTMF is something we use regularly ... Nov 13, 2016

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Foundations of Amateur Radio

Ingenuity is the name of the game in Amateur Radio, building, inventing, solving and helping are all part and parcel of this hobby. We like to lay claim to being the source of all that is good in the world, all that was invented came from Amateur Radio first, right?

Seriously though, sometimes we pick up a technology along the way from other places.

If you've ever picked up your microphone and pushed one or more buttons on it whilst the push to talk button was down, you've likely used this technology that's set out in an ITU recommendation called Q.23. It has the quaint title of: "Technical Features of Push-Button Telephone Sets". It's a brief document as such, all of four pages, two title pages and one mostly dealing with why this Push-Button idea is a great one and how it relates to international phone calls etc.

The meat is in the final page, showing eight frequencies and how you combine them to generate voice frequency signals.

If you've been paying attention, you might recognise this as DTMF or Dual Tone Multiple Frequency signalling.

It's pretty nifty. Send two discrete frequencies at the same time across some link and decode it at the other end. It's nifty because these frequencies might happen during a normal conversation, but not at the same time for a particular duration.

As Amateurs we use this to communicate with our repeaters, to send signals to it, to activate links, to power on and off stuff and all manner of other interesting things.

So, how does it actually work?

Well, you have two sets of four non-overlapping frequencies which you can combine into 16 different combinations, enough for 10 digits, four letters and two symbols. To make this work, the frequencies must be pretty stable, the ITU recommends less than 1.8% off the nominal frequency and distortion must be 20 dB below the fundamental frequencies.

Today producing such a thing is trivial, a chip for a dollar will do the job and another one at the other end to decode it. Four bucks and you're good to go for two-way DTMF at both ends. Bargain.

Being the curios type I went looking to find out what a DTMF circuit might look like before we could buy such products. The closest I came was a build-your-own voice mail system in BYTE! magazine of April 1982 using LM567 tone decoders, but a quick look at the box shows that these are also something that we'd call an Integrated Circuit.

I'm going out on a limb here, since DTMF has been around since it was first supplied to customers in 1963 and suggest that the original DTMF decoders were not quite as trivial as a dollar chip. They likely contained many discrete components including eight separate filters and ways to combine them so signals could be added to each other to detect the existence or absence of a specific tone, but I've yet to actually lay eyes on anything more fundamental than the tone decoders.

That being said, you can connect your all-in-one dollar chip, the CM-8870, to something like an Arduino and do your own decoding of DTMF signals.

Seems that the 1982 BYTE! magazine article was just the beginning of the revitalisation of DTMF, robot controllers, home automation, in-vehicle signalling and more, not to mention, using it to activate IRLP and other wonderful radio services.

Before you start sending me email about this non-Amateur invention, I'll point out that Amateurs also didn't invent copper wire, that was two Scots, or was it Dutch, I forget, fighting over a coin.

I'm Onno VK6FLAB

The joy of Amateur Radio Nov 06, 2016

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Foundations of Amateur Radio

Last week over dinner I was chatting with a friend about Amateur Radio in a discussion about things that take your fancy. I was attempting to explain what it specifically was about this hobby that keeps me coming back. I talked about invention, about exploration, about fishing and catching that elusive station, but looking back over that discussion it occurred to me that none of that is what "does it" for me.

Sure, those things are part of it, but it's not what makes me turn on my radio, what has my face light up in delight or allows me to get out of bed in the middle of the night to explore the bands.

A brief phone call with another Amateur to wish him Happy Birthday twigged me to what's going on. He asked me: "What's new in your world?", and my answer, innocuous at best was: "Well, last weekend I heard a Japanese station from my QTH."

In the past I've mentioned that I've made many contacts with Japan, looking at my log, 63 of them, on 10m and 15m, so the fact that I heard Japan wasn't particularly special. I don't recall the band on which I heard the station, so that's not it either.

What was different was that I heard it at home, my QTH. The place where there is S7 or higher noise all the time, where I cannot put up a full antenna and make do with a dipole in the garage and a single band vertical on the roof.

Looking back at the conversation it occurred to me that what I like about Amateur Radio is the unexpectedness of it, the surprises that come your way, like little gifts waiting to be unpacked. It reminded me of a journey coming back from a club meeting last year when I spent the time going through the entire frequency range of my radio.

There's quite a bit to visit. The radio in the car does 100 kHz through to 56 MHz as a single range, then has several other ranges. My hand-held is capable of 500 kHz through 999 MHz. Between the two I have the ability to pick up most of the stuff that's around.

If that's not enough, there are many online radio receivers to connect to using all manner of different tools, the simplest to get running is probably WebSDR, where you visit a web-page and pick out the frequency you want to hear.

All this RF activity is happening all around us all the time. There's the local Top-40 radio station, the talk back shows, the local community stations, single frequency specialist broadcasters, the local public transit authority, etc. etc. You never know what you're going to find and what you're going to hear.

Many Amateurs I speak to started off as short-wave listeners. I had a short-wave radio when I was growing up, but it never much did anything for me. Now that I'm an Amateur and I understand what's happening to make those distant signals arrive at my ear, I'm becoming the short-wave listener I never was.

That's what I like about Amateur Radio. Unexpected gifts being shared across the globe from people, cultures and experiences that bring us all together.

For me, Amateur Radio is about the thirst for curiosity, the never ending supply of wonder and the joy in hearing them arrive un-announced at my doorstep.

I'm Onno VK6FLAB

Where do you start with this Amateur thing? Oct 30, 2016

Show notes

Foundations of Amateur Radio

Being on air and getting on air are part of the journey that you undertake when becoming a Radio Amateur, but what happens before all that, what do you need to get your foot in the door as it were?

If you're listening to this via a radio, you're already on the journey, but if you've downloaded this as a podcast, you're not far behind and your journey towards becoming a Radio Amateur is just around the corner.

Let's start with a few things before I start with the journey itself. First of all, every country is slightly different, so while I can give you specific examples, they'll be valid for only a few people.

In becoming a Radio Amateur you'll have to undertake some learning, pass a test and get a license. This license is specific to you and for most, if not all Amateurs, the license itself is for life. That means that if you have already passed an Amateur License Test in your past, you're likely still a Licensed Amateur today.

Being a Licensed Amateur, or having a License, doesn't actually mean that you can operate your own station, for that to happen, you need a callsign and the requirements for a callsign are that you have a license. It's like learning to drive. Once you've passed your driving test you're able to drive a car, but you need a current drivers' license to actually get behind the wheel.

In most cases there are different levels of license. Going back to the car analogy, you can drive a car, a moped or a truck, but not with the same license.

In Amateur Radio there are several different types of licenses. For example in Australia there are three, in increasing level of responsibility, a Foundation License, a Standard License and an Advanced License. In the United States there are also three, The Technician License, the General License and the Amateur Extra License. In the United Kingdom there are also three, the Foundation License, the Intermediate License and the Full License. Germany has two types and calls them Class E and Class A.

In essence the idea is that with more learning comes more responsibility and a change of license. To muddy the waters a little, as time passes and Amateur Radio evolves, license types change and merge, new ones are introduced and old ones vanish.

For example, to my knowledge there are no countries requiring Morse Code as a skill for an Amateur License. That wasn't always the case and until 2003 the World Radio-communication Conference essentially left it to individual countries to decide if Morse Code was a requirement for specific privileges.

As an aside, Citizen Band or CB, where anyone can walk into a shop, buy a CB radio and use it without passing a test and getting a license is fundamentally different in that the license is linked specifically to the radio itself. There is still a license, and to operate, the license needs to be current, but it's intrinsic to the radio itself.

Amateur Radio has the license linked to the person, rather than the radio.

Now that you know a little about the landscape, the next step on your journey towards becoming an Amateur is a little less nebulous. It's probably a good place to start at the beginning and work your way through that and as time goes on and your confidence and experience improves, to add to the learning and do the next thing as it occurs to you.

I should point out that there are Amateurs who believe that it should be your goal to get the highest level of responsibility, but my perspective on this is quite different. This is a hobby, your hobby. If you want more responsibility, then go do some learning and pass a test. If you're happy to do what you're doing, then do that. Don't let anyone tell you that you must increase your learning, just because they tell you to or that it's the done thing.

For me, I've set a personal goal to work a hundred countries using 5 Watts and every contact I make counts towards that. If you've been listening for a while you might have noticed that I've not bragged about any remote contacts and that's because I've hardly been out and about on-air using my own callsign. Too many other things to do and I'm in no hurry while I'm learning and having fun.

So, what's next?

The simplest is to find yourself a local Amateur and get them to point you to the local training group, but if you're not able to do that, contact your National Amateur Radio Association and ask them who provides training for you.

You're likely to find a local website with information, or you might listen to the local Amateur Radio News Broadcast where the local training organisation tells you about upcoming courses.

The first level of license is likely to be pretty simple, think a weekend of listening and playing with radios, followed by a written and practical test. If you have issues with travel or learning, you're likely to find that there are ways to help you get on air, so don't give up, just because you can't drive to the big smoke, don't have a local training organisation or are hopeless at doing tests.

Amateur Radio takes all types and you too can find a hobby of your liking.

I'm Onno VK6FLAB

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