Foundations Of Amateur Radio

Foundations of Amateur Radio Have you ever had your radio on, listening around, say on 40m and heard the following: "CQ, CQ 40m, this is VK6FLAB, calling CQ 40, CQ 40m, calling CQ" Apart from the fact that the station calling seems pretty desperate for a contact, you're tuned to 40m, why on earth would you actually mention that, what's the point of telling me what band you're calling on, when clearly I'm hearing you on that band? The answer to this question is in harmonics. At the heart of every radio is an oscillator, set to some or other frequency that forms the basis of all that happens around it. In order to arrive at different frequencies, we add and subtract, double and halve frequencies, all combining to arrive at the various frequencies and bands we use. I'll use some fictitious numbers here to give you an idea of what's happening. Imagine that you have a 3.5 MHz oscillator. With it you can double it to 7 MHz, double that to 14 MHz, double it again to 28 MHz, that's 80m, 40m, 20m and 10m, just

Foundations of Amateur Radio Today we enjoy radio using all manner of different so-called modes. The ones that most people are familiar with are FM and AM. In fact digital radio DAB+ is another example of a mode. In Amateur Radio we have a few more to play with, Single Side Band, or SSB, countless other digital modes, CW, or Carrier Wave are all different approaches to getting information from one place to another. If you have a radio that uses SSB, you'll soon notice that there are two versions of SSB, something called LSB and something called USB, or Lower and Upper Side band. If you tune around the bands you'll soon notice that some stations are using Lower Side Band and others are using Upper Side Band and there seems to be no rhyme or reason to it. Actually, there is a method to the madness. First of all, commercial and military HF radio all use Upper Side Band all the time. Radio Amateurs are a bit more traditional and we have the following basic convention. For voice signals on frequencies lower th

Foundations of Amateur Radio Today I'm going to talk about housekeeping, that is, the things you should be doing while you're doing the things you like doing, like making noise on air. The topic of Logging is one that continues to attract comment, suggestion, frustration and on occasion ridicule. Let me start with the fact that the very first contact that I made was not logged. I can tell you exactly which day it was, Sunday, April 17. I can tell you where I was, Stirk Park in Kalamunda in Western Australia. I can tell you that the other station was a Japanese station, but that's all I can tell you. I don't know the time, the band, likely 10m or 15m, I couldn't tell you their callsign, even though I'm pretty sure that I wrote it on a random piece of paper at the time. It simply hadn't occurred to me that I should actually log that contact, or that I'd ever think back to that day and wonder whom I spoke with. So, if you've not yet been on-air, get your logging sorted out now. It doesn't have to be fancy, i

Foundations of Amateur Radio There are things to say and things not to say as a radio amateur. Let's start with swearing on-air. Each jurisdiction is different and changing. The Australian Radiocommunications License Conditions Determination, or LCD has nothing to say about content. It's all about bandwidth, frequency and modes. The rules in the USA discuss "obscene or indecent words or language", but there is no definition of what that might mean. A word in one country is meaningless, where in another it's completely unacceptable. Our station signals travel around the globe, so it's prudent to moderate your language and to refrain from creating a situation where offence might occur. Of course, there are those who take this to the n'th degree. There is a perception that you cannot use the words K-Mart or Target on air, instead referring to these locations by some euphemism. There is nothing in the rules saying that you are prohibited from stating that you purchased a tube of SWR grease for $1.49 from Targ

Foundations of Amateur Radio Today I'm going to talk about QRP, a term that's used in various different environments and one that I've used in the past. So, let's start at the beginning. QRP is a three letter code, part of the so-called Q-codes, that can either be a question or an answer. It's used in Morse communications to either ask "Shall I decrease transmitter power?" or to answer "Yes, decrease your transmitter power." It was perfectly valid for a kilowatt station to ask: "QRP?" and for another kilowatt station to answer: "QRP". Language changes over time, meanings get inverted, changed, adopted and transformed. The three letter combination, Q-R-P, is no different. Today in Amateur Radio, the three letters are more like a word, rather than a code and the meaning has changed to indicate that a station is running low power or as an indication to others that they're likely to be a weaker signal that requires a little more effort to pull out of the noise than any other station. As you might know, propaga

Foundations of Amateur Radio There is a recurring question that never seems to get a straight answer. Why are we using 50 Ohm impedance and not 75 Ohm? The more people you ask, the more answers you get. There'll be commentary about standing waves, SWR, loss, incompatibility, soldering, cost, velocity factor, diameter, susceptibility to noise and the list goes on and grows, the more people you ask, the longer the list. Of course as time goes by, people remember stories told to them, guess, or even, how to say this, make stuff up. To steal a phrase: "Why is it so?" In the 1930's, when most of us were not even the apple in the eye of their parents - let alone their grand parents - coaxial cable was being developed for kilowatt radio transmitters. There are two aspects to consider, the amount of loss against length and the ability of the coax to handle power. Without going into the maths, there's plenty of that online, the lowest loss for air-dielectric cable is 77 Ohms. If we look at the peak power handlin

Foundations of Amateur Radio This week I'm going to have a look at something called a Q-code. Last week I talked about a few aspects of operating. One of the inventions associated with human speech is the short-cut, a way to quickly say something rather than use the whole story. Before Amateur Radio this started on the telegraph with shortcuts called Q-codes. Think a three letter combination, starting with Q, followed by two letters. QTH, QSL, QRZ, QLF are examples. Language, just like Amateur Radio is an evolving feast. You'll find people writing articles about the abuse of Q-codes in speech going back to the early days of voice operation. The Q-code started with Morse Code as a way to quickly say something without needing to key the whole thing. This has flowed over into voice. You'll hear people use Morse-Code-isms in day to day language, 73, QSL, QTH and others are all examples of shortcuts that have no actual place in speech, but none the less have taken hold. Having said that, of course there is diff

Foundations of Amateur Radio Today we're going to look at operating procedures, that is, what to say, when to say it and when not to say it. Amateur Radio being over a century old has lots of traditions and lots of quirky exceptions to rules, but you'll learn those as you go on air and make mistakes, and assume that you'll make those, probably regularly and every now and then someone will gently correct you, or you'll get shouted at, either way you'll get feedback. It's generally a better idea to figure out what's going on before you even open your mouth, so lets look at some things that really need to be second nature. Your callsign is always last. Always! That way the other station knows who you are, every time. I realise that you might not think that this is important, but just imagine that you've been inconsistent with this across your activities and one day you're in an emergency. Now it's crucial to know who is who. If you always do it the same, always your callsign last, then you'll do that in an e

Foundations of Amateur Radio In the past I've talked about our hobby and lightning. I've done it on more than one occasion, talked about cows and lightning strikes, about earth bonding and the dangers associated with lightning that's not directly overhead, but close enough to matter. On the weekend I learned the difference between saying something and seeing something. A group of Amateurs, went out camping, about two hours from anywhere in the middle of the bush to participate in an annual field day. We'd set-up our various overnight shelters, erected two marquees and proceeded to construct our portable shack. We were there for two nights. On the first night, the heavens opened up and the rain poured down, soaking the ground good and proper. We were lucky, our camp was at the top of a hill and drainage was great. At one point in the middle of the night I was standing outside in the rain, getting wet while attending to some ablutions - an unforgettable experience, but I digress. The next day the camp was i

Foundations of Amateur Radio Today's Amateur Radio is less like the valve or transistor based radio and more like a computer. So much so that most radios today have a mechanism to connect the radio to a computer. This mechanism is called a Computer Aided Tuning interface, or CAT interface. It's a mechanism that's used to allow two way control information to be shared between the radio and a computer. This interaction is a serial connection, generally something called RS232. This is a standard that was developed in 1962 and it specifies things like timing, voltages and other attributes. The electronics from that era don't look much like the ones of today and most of the challenges with getting this stuff to work is related directly to these differences. It should come as no surprise that each manufacturer has their own take on what this whole contraption looks like and most of this technology is not directly compatible across radios. So, let's imagine that you've got a radio and a computer and they're phy

Foundations of Amateur Radio Today I'm going to talk about operating procedures. Before groan and tune out, stay with me for a moment, this is important for all amateurs, even you. We as amateurs have a range of bands allocated to us. These bands cover a whole chunk of spectrum that we in many cases share with other users. They might either share the same band with us, or the other way around, we with them. Our bands might be right next to theirs or overlap in some part. To make things more interesting, these bands are unfortunately not uniform across the world. For example, in Australia part of IARU Region 3, the 40m band runs from 7.0 to 7.3 MHz. In Region 2, it's the same, but in Region 1, it only covers 7.0 to 7.2 MHz. If you look at the 80m band it's worse: Region 1 uses 3.5 to 3.8 MHz, Region 2 uses 3.5 to 4 MHz, Region 3 uses 3.5 to 3.9 MHz, but in Australia we can only use 3.5 to 3.7 and 3.776 to 3.8 MHz and that last little bit, the DX window, only if you hold an Advanced License. This can have

Foundations of Amateur Radio Today I'm going to talk about repeaters. These invisible services that sit on a particular frequency and do magic things to your signal. First of all, the best way to think of a repeater is to think of it as two radios. One is the receiver, the other the transmitter. The way it works is that the receiver hears your signal and sends that audio to the transmitter which sends it out over the air. For this to work, there need to be two frequencies in use, the one that you're transmitting on and the one that the repeater is transmitting on. From this simple idea, many different things flow. There is no rule that states that the receiver and the transmitter need to be in the same place, let alone on the same band; if they're on different bands, it's called a cross-band repeater. If the receiver and the transmitter are on the same band, the system needs to deal with the fact that a strong signal is being transmitted by the repeater right next to where the receiver is. If you're not

Foundations of Amateur Radio There is an interesting phenomenon that I've begun to notice and now that I've seen it, it's hard to un-see. Think of it as the equivalent of the little dot in the top right corner of the screen that signifies the end of the reel to a movie projectionist. Once you've seen it, you can't miss it ever again. If you haven't, sorry, you will and now you'll carry that with you for the rest of your life. Across Amateur Radio, from Foundation and Standard through Advanced or Technician and General though Extra, there is this thing where people get together and ask each other how to get started. It's amazing to observe, grown adults every one of them, not daring to take the first step. It ranges from keying your microphone for the first time, through to making your first HF contact, through building an antenna, going portable, climbing a mountain, making contact with the International Space Station, doing a contest, building a radio or erecting a tower. It seems that collectively we've

Foundations of Amateur Radio The single largest topic of conversation in Amateur Radio is about Antennas. The discussion often starts with one amateur telling another amateur about some or other amazing antenna, followed by a heated discussion about the merits or pitfalls of that same antenna and why they would never ever consider using it and why it's a waste of money, or some other rationale. Let's take for example the discussion of Dipole versus Vertical. There are those who will tell you that they'd never ever use a Dipole and similarly those who'd say the same about a vertical. Assertions of suitability aside, let's have a look at what we're talking about, first of all. In rough terms, a dipole is an antenna that is generally suspended between two sky-hooks, its fed from the centre and has pretty much an omni-directional radiation pattern. That is, signals arrive and depart from this antenna, pretty much evenly in all directions. Now, before you get all excited. It's not exactly the case, since it's n

Foundations of Amateur Radio Today I'm going to talk about dipoles. You know the tried and true antenna, the go-to design for getting on air, the simple first antenna you ever make, the one you learn from, you know the one. It's the mainstay of every amateur, of any field-day, of all things Amateur Radio. It's a simple thing. Using metric, rather than imperial measurements, but the point stands, you use the speed of light in vacuum divided by the required operating frequency and you get the overall wave length for that frequency. In absolute terms, roughly 300 m/s divided by 50 MHz, gives you 6 meters. Surprise, that's the band name for 50 MHz. Now the dipole is a half-wave contraption, so, 6 meters divided by 2 gives you 3 meters for your total half-wave dipole. Each leg is half that, a quarter wave length, so you have 3 meters divided by 2 again and you end up with two bits of wire, a meter and a half long each. If you're following along, that's 300 divided by 50 divided by 2 divided by 2, or using the

Foundations of Amateur Radio Today I want to raise the topic of batteries. Specifically, sizing the battery. You can do as I did naively, look at the manual, see that the current consumption of your radio is 22 Amp, decide that this means that you need to get a 26 Ah battery to use your radio for 1 hour. Being the portable type, I got two, 52 Ah in total. Some time has passed since I made that purchase. I've learned that I can get a lot more out of my battery than 2 hours. I also learned that lugging 56 Ah around is not fun. Having learned this, what could I have done to improve? Well, first of all, the 22 Amp is for Transmit. According to the manual, on receive it's only using 1 Amp. If you're not transmitting all the time, then you're not drawing 22 Amp the whole time. The ratio between send and receive is the Duty Cycle, often expressed as a percentage of the time spent transmitting. Another thing to note is that 22 Amp is when you use full power for a particular mode and band combination. On my radi

Foundations of Amateur Radio There is a recurring topic in Amateur Radio circles, called "permissions", or "rights", or some other word indicating "entitlement". It's a conversation that has been happening since the dawn of radio experimentation and will continue until well after our Sun has burped it's final sun-spot. In Australia, there are three classes of License, in increasing level of responsibility they are Foundation, Standard and Advanced. There is an ongoing tension between these categories. Some higher level responsible licensees look down on the class with less responsibility, and the reverse is also true. This separation of class is an evolutionary one. As I said recently, the most recent overhaul, more than 10 years ago, back in 2005 saw the introduction of the Foundation Class and the consolidation of various classes into Standard and Advanced. There are current noises being made about how this needs to change. There are those who suggest that the Foundation Class needs to have access to mo

Foundations of Amateur Radio The history of the evolution of amateur licensing is a nebulous affair, told and re-told, moulded, changed and interpreted by the story tellers along the way. There is an on-going debate about how the restructure of the licensing regime in Australia, in 2005, has affected our hobby. In 2005, after a 10 month review period, three classes of license were established, a new Foundation class, an a re-imagined Standard and Advanced class, using existing novice and novice limited licenses to create the Standard class and combining limited, intermediate and unrestricted licenses into the Advanced class. I've touched on this subject before, back in 2011, when I noted that those who forget history are doomed to repeat it. The ACMA published the review in May of 2004. It summarises the responses about the introduction of the Foundation licensing option. It opens with, "Over two-thirds of submissions were in favour of the introduction". It goes on to say that the most common reason for

Foundations of Amateur Radio There are skills that come from thinking and there are skills that come from doing. There is place for both in Amateur Radio. There is nothing in the world that is like the experience of working a pile-up, unless the trading floor of the New York Stock Exchange counts, but I've not personally been there and it doesn't look as intimate as a radio shack. Working stations across the planet that are coming in thick and fast is an amazing thrill, not unlike getting onto a roller-coaster. The long slow journey to the top of the ride is calling CQ, the crest of the hill is the first response and the loop-de-loop is when they're all calling at the same time; rolling back down to earth at the end of the ride is the petering out of the calls, only to start again. If you've never experienced it, I'd strongly recommend that you find a way to put yourself in the position where you are exposed to this absolutely thrilling experience. So, what do you do when you're actually in this situatio

Foundations of Amateur Radio This is episode 236 or so of my weekly contribution to this hobby. As you may have heard me say over the past few weeks, this is now available as a podcast which you can subscribe to. It's available at http://podcasts.itmaze.com.au and you can also search for my callsign, VK6FLAB on iTunes and find it there. I'm mentioning this because each podcast also contains a transcript, which you can use to search the content. I've been doing this podcast since May 2011 and in that time I've covered many topics. I get wonderful feedback from you about each segment, thank you, and I also get requests for content. Often new listeners ask me if I could talk about XYZ topic, and I'm finding more and more that in fact I have talked about such a topic. That's not to say that I won't revisit a topic if I have information to add. For example, I was in the process of researching baluns, got distracted by word-use and will revisit. As I'm doing the research I'm realising that the rabbit hole goes