Episode: 4633 Title: Ham Radio Licence Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr4633/hpr4633.mp3 Transcribed: 2026-07-31 16:15:35 (official HPR transcript) --- This is Hacker Public Radio Episode 4633, for 2026-05-06 Today's show is entitled, "Ham Radio Licence" The host is Lee and the duration is 00:14:23 The flag is Clean, and the license is CC-BY-SA The summary is "Lee talks about the curriculum of the Radio Society of Great Britain Foundation Licence" You are listening to a show from the Reserve Queue. This show was submitted in June 2025 to cover occasions like this where there are gaps in the schedule. Hi I'm Lee, today I'm going to go on a brief tour of the Amterrajo Society of Great Britain Foundation License curriculum, with particular attention to the technical aspects. Why would you want to get this license? Well basically it's the bare minimum of what's required to legally operate what's referred to as Amterrajo or Hammequipment, particularly if you want to transmit using this equipment in the United Kingdom. If you're not in the UK they like to be other foundation level licenses that you can take. The equipment itself may not be costly, it could just consist of handheld battery-powered walkie-talkie-style radio such as bow-fane that can be quite fun the 50 pounds aware of the equivalent is in your currency of choice. One of the first things that is taught is the basics of radio. This includes various symbols in units of a relate to electrical circuits such as amps for current and volts for potential difference. It talks about how both large and small quantities can be written down using different sizes of these units such as millimeters for distance rather than meters. We learn about batteries and how you can draw diagrams that represent an electrical circuit schematically and the fact that some substances conduct electricity while others don't so much. We also learn that there are more electrical quantities such as power which is the right which engines been transferred or resistance which is how much a particular conduct tends to limit the current flowing for it. One of the basics is a general formula which connects the three quantities of voltage current and resistance, either for a whole circuit on one part of it. It is noted that parts of the circuit may be aggregated either in series or in parallel with each other, depending on the topological layout of the circuit. The manual introduces electrical components such as light and knitting diodes or LEDs for example. We learn that electricity might flow for a circuit as you might expect in one steady direction called direct current, also that there is an alternative where electricity might be flipping direction very quickly and as alternating current. So the charge carrying particles called electrons don't get very far from where they started in that case and yet power is still effectively transferred in such a circuit. We learn that electrical signals can oscillate at a certain rate, that's their frequency and that different frequencies often combine which other in complex signals. The fundamentals of the electromagnetic waves we call radio waves are introduced and a description of the different frequency ranges of those waves is given since we distinguish between different types of radio waves according to their frequency. If you've ever used an old fashioned radio over dial, you'll know the radio always has to be tuned to a particular frequency to pick up a certain broadcast. The technical basics chapter covers the physical and mathematical properties that come into all waves, whether they be sound waves, water waves or electromagnetic waves. These properties are wavelength, speed and frequency and we learn a simple formula that relates these three quantities and at the same time a presented with some real-world examples so for example, the radio wave traveling at the speed of 300 million meters per second oscillates 300 million times a second and feeds oscillation travels one meter. The curriculum then goes on to describe a type of signal known as digital signal, when the information content of the signal has been decomposed into a large aggregation of bits, ishif which is only two possible states that may be described in several ways including as voltage levels so high or low or in logical terms, true or false or even mathematically one or zero. There are many situations especially nowadays we're sending information in the form of a digital signal is preferred in order to be more efficient or to help reduce interference and distortion. We're then told how real signals for which the proper term is analog can be converted to the more artificial digital signals which is necessary if they are to be transmitted digitally. There's a chat to in the amt to rage M and you're about receivers. We find out a rage or a receiver can often be compartmentalized in terms of its parts into an antenna, a tuner, strike amplifier, a demodulator, an audio amplifier and an output loud speaker. The curriculum covers knowing what each of these components does but also states that nowadays several steps in the process may be carried out digitally so that these components still exist but they're implemented logically with a microprocessor rather than being separate physical components you could see in touch. There's another chat to in the amt to rage or foundation manual about transmitters. Your basic transmitter will have it in this order a mic, an amplifier, a modulator, a rage or frequency pan, a fire and an aerial. We learn about carrier oscillators, these create a sinusoidal signal of a particular frequency and the measured signal is in some way piggybacked onto the main signal. So even if the rage or transmission in practice occupies a wide frequency range is this central carrier frequency that you normally talk about when saying what transmission frequency is. The modulation and demodulation is all about respectively combining or extracting a message signal with a carrier frequency to convert between the message signal you want to send or receive and the actual rage or signal going over the airwaves. I talked about this in particular in HPR4291. Various types of modulation discussed with names like FM, AM and CW. The first two are well known, with respectively the frequency or amplitude being the property of the carrier that's changed in step with the message. The latter is a little less known but stands for carrier wave modulation and just means turning the carrier tone on and off in some comprehensible sequence. The main example of this being Morse code. Side-banted discussed which are phenomena where the frequency spectrum of the rage signal shows a symmetrical pattern of frequencies in use above and below the carrier frequency, which is a direct result modulation. A final quantum modulation, again less familiar than FM and AM, at least if you grew up when those were how you listened to music, is data modulation. And this is where the signal is converted to digital ones and zeros and these decide what tones are played in console of each other while the data is being transmitted. If you are using the internet in the late 90s or early 2000s and had a modem you're probably not what that sounds like. We finally learn about the power amplifier which is the component that boosts the low-level electrical signal in your rage or handset up to something assessing lots of energy that can rage out from the antenna and travel long distances at the speed of light in the form of rage air waves. The syllabus covers learning about feed as an antennas. The feed is the wire that carries the signal from the sending equipment to the antenna and is often the coaxial cable meaning it has a central conductive core to carry the signal surrounded by an insulator and this itself is then shielded all around by conductive ramp. The idea is to stop the signal dissipating on rage editing away before it reaches the aerial. The other type of feeder which I'm not that familiar with is a twin feeder where two wires are used with a space between them and a signal of exact opposite polarity travels down each wire. We learn that feed has a property a bit like a resistance I mentioned earlier but this is called impedance. The thing that's important about impedances that signals will go through a system best when the impedance each stage is matched to have the same value as at all other stages. But most of what I've talked about so far is pretty theoretical but finally in the manual breaks is something very practical which is the types of plug for feeder cables. These have names like n-type, b-n-c, p-l-2-5-9 and s-m-a and you need to be able to recognize and distinguish between them. We also learn that for very high frequency rage o-waves, your typical feed decay was not so good but something called a wave guide which is like a square metal tube will do the same jobby. The manual then discusses the main categories of rage o-n-teller. That's the sticky up bit that emits or captures rage o-waves. I won't describe in detail but the main types of dypo-n-tenas, one quarter wave-gram planes, the yag-y-n-tena, the 5-8-wave-gram plane and the end-fed long wire antenna. We learn about the differing radiation pattern that emits from the different shapes of antenna which for example decides how much of the signal goes in each direction. For some purposes you want the signal to rage out in every direction, for other purposes you might want it to primarily leave or be picked up from a particular direction. The manual discusses the metrics used to describe the pair-up of particular antenna when being used. This is something known as the effective rage power and is related to what is known as the antenna's gain which is basically how good it is at putting out its signal and that depends on factors such as its size and shape. We also learn about polarisation which is to do with whether the rage o-n-teller goes out horizontally or vertically. So we're taught when debugging rage o-s at up a good thing to have is a special type of meter that detects how much of the signal is going into the air and how much of it is reflecting back into the equipment. For example if there is an impedance mismatch or the error is the wrong length. The meter is called does standing wave ratio meter or SWR meter. There's even a device that can sometimes sort out problems called an antenna matching unit or antenna tuning unit that's AMU or ATU. Another useful bit of kit is a bail-in. This can convert where you might have a coaxial type of feeder and really wanted to twin feeder which some type of variables such as a dipoware will require because the feed is then balanced. The manual talks about a dummy load. This is something that can be plugged in that will take in the signal perfectly as far as the transmitter is concerned with actually rage oating it as an aerial wood. This is useful for testing equipment. Another part of the syllabus is about rage o-wave propagation. That is how it travels through the air, how far it can go, what my alter its course dissipate it or affect it in other ways. We learn that there are three main effects. These are reflection, refraction and diffraction. Reflection is where the signal bounces back off something. Refraction is where it is bent towards a new direction and diffraction is where it scatters for example at the edge of something. The most interesting effect is the refraction of some wavelengths of waves as they enter the ionosphere layer of the atmosphere. This can bend the waves back towards the ground and it's this effect that means that some waves can travel between points on the earth, even when the earth's curvature would otherwise prevent this due to their being no direct line of sight through the air. The fact that the downward coming waves from the ionosphere can then even bounce back up from the ground or ocean and so do a back and forth between the ground and ionosphere for thousands of miles means that rage o-signals from a suitable transmitter can even be received on entirely different continents. And this is without the help of artificial satellites or undersea cables. So that's it, that's the main technical content of the foundation license. However, a lot of the syllabus which I won't go into in detail here is not just about technical aspects but also about being safe, responsible, alerting what the regulations across the world are that generally allow rage of transmitters and receivers to coexist with each other without people interfering with disrupting each other's important communications as they go over the airwaves. There's a chapter about practices and procedures for using ampturator equipment, things like announcing your allocated cool signs are that people know who it is they're hearing or communicating with. There's a chapter about safety from electrical safety working with high voltages to physical safety climbing ladders to SAR perials. There's a chapter about electromagnetic compatibility that's mainly about not causing interference to other people's equipment, particularly their TVs, rageos, phones or other wireless systems. Part of the syllabus is becoming familiar with the various bands that exist and how these can and can't be used. Since only select frequencies have been made available parameter transmissions, this is known as the in quotes schedule. Finally, the manual talks about the foundation exam. This may have changed slightly by the time you're listening to this, but when I took the exam in 2025, it consisted of 26 questions and I took it online with an refrigerator remotely watching a listening to me via camera and mic just to check the answers were my own work. In terms of what needs to be memorized a lot of the more technical data is made available in a data sheet that can be printed out and referred to in the exam. And there is a little maths, but most of it at this stage is trivial enough to be done with mental arithmetic, that simple calculator would be allowed to be used if desired. So for me taking the exam was a pleasant experience and while I struggled with some of the questions I finished well within half the lofted time and though I did not get full marks as called well enough to pass. I've only just started experimenting with the equipment so far with software defined radio reception and understanding the many settings of my handsets. At the time I took the exam I was in a ground floor flat so I was not having much luck reception wise, but now I'm living near the top of the adjacent building to where I was before, so it might be our fair better going forward. I know hand radio is a popular topic on HPR and did ask in Fallen or Camp last year if there was any relation between the word radio in HPR and radio as in hand radio and your answer was pretty much there's no direct connection but they are connected in spirit as it were. Anyway, I hope some of this has been of interest. Thanks for listening, goodbye. 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