• [FOAR] The power supply connector dance contest... (14/21)

    From FOAR via rec.radio.info Admin@21:1/5 to All on Mon Jul 18 13:48:30 2022
    [continued from previous message]

    If you want to make noise at your actual shack, the antenna might be a
    piece of wire hanging from the balcony after dark, or an antenna clamped to
    the railing. You can use a magnetic loop inside your house. Some
    enterprising amateurs have tuned up the gutters in their building, or made
    a flagpole vertical, or laid a coax antenna on the roof. Have a look for stealth antennas, there's a hundred years of amateurs facing the same

    My own station is very minimalist. There's literally a vertical antenna
    clamped to the steel patio. Using that I'm working the world with 5 Watts, 14,000 km on 10m, no kidding.

    Getting on-air and making noise doesn't have to start and finish with a
    Yagi on a tower. There's plenty of other opportunities to be an active

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201213.foundations-of-amateur-radio.mp3

    2m reciprocity and other assumptions

    Posted: 05 Dec 2020 08:00 AM PST

    Foundations of Amateur Radio

    Over the past nine and a half years I've been hosting a weekly radio net
    for new and returning amateurs. Called F-troop, it runs every Saturday
    morning at 0:00 UTC for an hour. Feel free to join in. The website is at http://ftroop.vk6flab.com.

    In making the better part of six thousand contacts during that time I've
    learnt a few things about how nets work and how there are built-in
    assumptions about how a contact is made. There are several things that seem universally accepted that are not actually supported by the evidence and repeating them to new amateurs is unhelpful.

    For example, there is an assumption that on 2m there is signal reciprocity.
    By that I mean, what you hear is what the other party hears. On HF,
    contrary to popular belief, this is also not universally true due to
    massive power and antenna differences and signal reports on FT8 bear that
    out - for example, my signal is often reported at least 9 dB weaker than
    the other station.

    The reason that on 2m this isn't the case is because in general there is at least one other transmitter involved, the repeater. If you're joining in
    via a remote network, either via RF or via the Internet, there are even
    more times when this isn't true, but let's stay with the simple scenario of
    a single repeater and two stations.

    If I'm using a base-station with a fixed antenna, my connection to the
    repeater is rock-solid. If you are using a hand-held and you're on the
    move, your connection to the repeater is anyone's guess. It could be great,
    it could be poor or even non-existent.

    Not only that, the repeater is often using higher power, sometimes much
    higher. On average the repeaters near me are using 30 Watts, the highest
    uses four times that, the lowest uses 10 Watts. In contrast, a handheld
    uses at most 5 Watts, but more likely than not, half that.

    Receiving a strong signal on a hand-held is simple, transmitting a weak
    signal to a repeater is not.

    The point is, you might be hearing me as-if I'm sitting next to you, but I might be hearing you on the other end of a really scratchy and poor, intermittent and interrupted link.

    If you add other repeaters and links with differing volume or gain settings
    to the mix, you get the idea that a 2m conversation may in many ways act
    like a HF contact.

    That implies that there are plenty of times when you should use phonetics
    to spell your callsign and anything else of interest, despite the often repeated assertion that you don't use phonetics on 2m.

    Another assumption is that 2m is less formal than HF. The people you talk
    to on 2m are likely to be local, perhaps people you've met at a HAMfest, face-to-face. You recognise their voice, you know their situation, their station and their habits.

    On HF however, you have contact with people across the globe, most of whom you've never met, will never meet, have no idea about, let alone have a relationship with. That's not to say that you cannot have a friend on HF, I have plenty of people whom I speak with on HF, often during a contest, whom I've never met, but whom I speak with regularly on air. I can similarly recognise their voice, their callsign and know what to expect.

    The point is that the more you look at the differences between 2m and HF,
    the more you realise that they are the same. Interestingly, as an aside, a contact on 10m or 15m can on plenty of occasions sound like a strong local
    FM contact.

    My advice is to not think of 2m as a "special" band, but to think of it as
    an amateur band with a set of conditions. By law you are required to
    announce your callsign every ten minutes and at the beginning and the end
    of each contact. Note that this doesn't mean at the beginning and end of
    each over. In case that doesn't make sense to you, a contact is the whole conversation from start to end. Each time a station transmits during that contact is an over.

    You should vary how you identify yourself, using phonetics or not, at the minimum required interval, or on every over, depending on the
    circumstances, not depending on the band.

    Look forward to making contact with you on what ever band. You can get in
    touch via email, cq@vk6flab.com is my address and if you're into Morse,
    this podcast is also available as a Morse-code audio file.

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201206.foundations-of-amateur-radio.mp3

    Prior Planning Prevents Poor Performance

    Posted: 28 Nov 2020 08:00 AM PST

    Foundations of Amateur Radio

    The other day I was adding an item to my to-do list. The purpose of this
    list is to keep track of the things in my life that I'm interested in investigating or need to do or get to finish a project. My to-do list is
    like those of most of my fellow travellers, unending, unrelenting and never completed. As I tick off a completed item, three more get added and the
    list grows.

    Given some spare time and to be honest, who has that, I am just as likely
    to find an item on my to-do list that was put there yesterday as an item
    that was put there 10 years ago. Seriously, as I migrate from platform to platform, my to-do list comes with me and it still has items on it that
    haven't been done in a decade, let alone describe what project it was for.

    Of course I could just delete items older than x, but deciding what x
    should be is a challenge that I'm not yet willing to attack.

    Anyway, I was adding an item to the list when I remembered seeing something interesting on the shed wall of a fellow amateur. There were two pieces of printed paper with a list of to-do items on it. Looking pretty much like my to-do list, except for one salient detail.

    Each to-do list was for a different project.

    At the time I spotted it I smiled quietly to myself and thought, yep,
    keeping track is getting harder for everyone.

    Bubbling away in the back of my mind this notion of a to-do list for a
    single project kept nagging at me. Yesterday it occurred to me why it was nagging.

    If you have a to-do list for every project then once the project is done,
    the to-do list is done. Not only that, the items on a project to-do list
    don't really grow in the same way as an unconstrained to-do list does.

    It also has a few other benefits.

    The sense of satisfaction towards completing a project is amplified as each item is ticked off and ultimately the project is done.

    I'm sure that project managers already know this, might even have a name
    and a process for it. No doubt there are aspects that I've not considered,
    like for example, the never ending range of projects or the trap of a miscellaneous catch-all project, but I'll cross those bridges when I run
    into them.

    As of right now, this gives me an improvement on my stifling life to-do
    list and it brings great satisfaction when I can tick off a whole project.

    No doubt you've gotten to this point wondering what this has to do with
    amateur radio?

    If it hasn't occurred to you, consider what's involved into setting up a portable power supply for when you activate on a field-day, what you need
    do to get logging working, what needs to happen to get ready for a contest, what you need to do when you're selecting your next radio, how you're going
    to prepare for the park activation next week and so-on.

    If you have insights into this, feel free to get in touch. cq@vk6flab.com
    is my address. Speaking of me, did you know that "Foundations of Amateur
    Radio" is a weekly podcast and that we're up to episode 285? If you haven't already and you're itching to get your hands on even more content, before episode 1 there was another podcast, "What use is an F-call?"

    It has 206 episodes and other than the name and my youthful self, the
    content is more amateur radio. If I've done everything right there won't be much in the way of overlap in those 491 episodes, other than the same unrelenting quest for new and exciting things to do with Amateur Radio, but then you already knew that.

    Now where's my podcast to-do list?

    * Tell you about "What use is an F-call?", tick.
    * Tell you that I'm nearly at 500 episodes, tick.
    * Finish recording this episode, tick.

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201129.foundations-of-amateur-radio.mp3

    When one WSPR receiver just isn't enough

    Posted: 21 Nov 2020 08:00 AM PST

    Foundations of Amateur Radio

    When one WSPR receiver just isn't enough

    The other day during a radio play date, highly recommended activity,
    getting together with friends, playing radio, seeing what you can learn, we were set-up in a park to do some testing. The idea was an extension on something that I've spoken about previously, using WSPR, Weak Signal Propagation Reporter, to test the capabilities of your station.

    If you're not familiar with WSPR, it's a tool that uses your radio to
    receive digital signals from WSPR beacons across the radio spectrum. Your station receives a signal, decodes it and then reports what it heard to a central database. The same software can also be used to turn your station
    into a beacon, but in our case all we wanted was to receive.

    If you leave the software running for a while you can hear stations across
    many bands all over the globe. You'll be able to learn what signal levels
    you can hear, in which direction and determine if there are any directions
    or bands that you can receive better than any other.

    We set up this tool in a park using a laptop, a wire antenna and a radio running off a battery. In and of itself this is not particularly
    remarkable, it's something that has been done on a regular basis all over
    the globe, and it's something that I've been doing on-and-off for a few

    What made this adventure different is that we were set-up portable about a kilometre up the road from the shack, whilst leaving the main WSPR receiver running with a permanent antenna.

    This gave us two parallel streams of data from two receivers under our
    control, using different antennas in slightly different conditions, within
    the same grid-square, for the purpose of directly comparing the data
    between the two.

    Over a couple of hours of data gathering we decoded 186 digital signals,
    pretty much evenly split between the two receivers. More importantly, the stations we heard were the same stations at the same time which gave us the ability to compare the two decoded signals to each other.

    One of the aspects of using WSPR is that it decodes the information sent by
    a beacon. That information contains the transmitter power, the grid locator
    and the callsign. After the signal is decoded, the software calculates what
    the signal to noise ratio was of the information and records that,
    additionally giving you a distance and direction for each beacon for that particular transmission.

    I created a chart that showed what the difference was between the two,
    plotted against the direction in which we heard the decode. This means that
    you can compare which antenna can hear what in which direction in direct comparison against the other.

    In telling this story another friend pointed out that the same technique
    could be used to compare a horizontal vs. a vertical antenna, even compare multiple bands at the same time.

    It looks like I might have to go and get myself a few more RTL-SDR dongles
    to do some more testing. If you don't have a spare device, there's also the option of comparing other WSPR stations that share a local grid square, so
    you can see what other people near you can hear and if you like, use it as
    an opportunity to investigate what antenna system they're using.

    WSPR is a very interesting tool and putting it to use for more than just listening to a band is something that I'd recommend you consider. I've
    already created a stand-alone raspberry pi project which you can download
    from GitHub if you're itching to get started.

    Thank you to Randall VK6WR for continuing to play and to Colin VK6FITN for expanding on an already excellent idea. If you would like to get in touch, please do, cq@vk6flab.com is my address.

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201122.foundations-of-amateur-radio.mp3

    For that one special event ...

    Posted: 14 Nov 2020 08:00 AM PST

    Foundations of Amateur Radio

    Radio amateurs like to do new things, celebrate, remember, bring attention
    to, and overall have fun, any excuse to get on air. One of the things that
    we as a community do is setup our radios in weird and wonderful places, on boats, near light-houses, on top of mountains, in parks, you name it.

    Another thing we do is create special callsigns to mark an occasion, any occasion.

    For example, to mark the first time the then Western Australian Chief Scientist, Professor Lyn Beazley was on air she used the callsign VI6PROF.

    When Wally VK6YS (SK) went on the air to educate the public about Rotary's
    End Polio Now campaign, he used VI6POLIO. More recently the Australian Rotarians of Amateur Radio operated VK65PFA, Polio Free Africa. When it's active, you'll find VA3FIRE to remind you of Fire Prevention Week in
    Canada, the Chinese Radio Amateurs Club operates B0CRA through to B9CRA
    which you can contact during the first week of May each year as part of the Chinese 5.5 Ham Festival.

    We create callsigns for other things too.

    Datta VU2DSI commemorates November 30th, the birthday of Indian physicist
    Sir Jagadish Chandra Bose named by the IEEE as one of the fathers of radio science, by operating a special callsign AU2JCB in his honour for a couple
    of weeks around the end of November.

    I mention this because it's not hard to achieve. It's called a "Special
    Event Callsign" and many if not all amateur licensing authorities have provision for such a callsign. Rules differ from country to country, some
    say that the callsign must be for something of special significance to the amateur community, others require that it's of national or international significance. In Canada for example, if you're celebrating an anniversary,
    it must be a minimum of a 25th increment.

    Different countries have different formats.

    The USA for example issues temporary one by one calls consisting of a
    letter followed by a digit followed by a letter.

    The UK offers GB and a digit followed by two or three letters. There's
    also "Special" Special Event Stations, which can have a format like

    In Canada there's a whole system based on what kind of event, what region
    it's significant to, who's operating it, and so on.

    In the Netherlands you can have a normal prefix followed by at most eight characters and an overall maximum length of twelve characters and you can
    have it for at most a year and only one at a time.

    In Germany you can use a standard callsign pattern with a four to seven character suffix, but only for a limited time.

    In Australia there's the traditional VI and a digit followed by any number
    of characters, but remember if you make it massive, getting it in the log
    is not always easy and using a digital mode like FT8 might not work as expected.

    What ever you want to commemorate, celebrate or bring attention to,
    remember that your callsign is only one part of the process. Consider who's going to actually operate the callsign, if you're going to issue QSL cards,
    if there are awards or a contest associated with the callsign, if there
    needs to be a website, if this is a regular thing, or a once-off.

    Another thing you need to consider is how you're going to publicise this callsign. There's no point in going to the effort of obtaining a special
    event callsign with nobody knowing about it, that's the whole point.

    No matter which way you jump, there's always a large range of special event callsigns on the air at any one time and making contact with one is often a massive thrill for the person operating the callsign, not to mention the
    person making the contact.

    So, if you have a chance to have a go, I'd encourage you to get on air with
    a special event callsign and make some noise!

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201115.foundations-of-amateur-radio.mp3

    It lives ... crystal radio with three components

    Posted: 07 Nov 2020 08:00 AM PST

    Foundations of Amateur Radio

    The idea of building a crystal radio occurred to me a little while ago. I committed to building one, supplies permitting, before the end of the year.
    I can report that I now have a crystal radio. It works, as-in, I can hear a local AM broadcast station, and it took a grand total of three components costing a whopping two and a half bucks.

    Before I get into it, this isn't glorious AM stereo, or even glorious AM
    mono, this is scratchy, discernible, unfiltered, temperamental radio, but I built it myself, from scratch and it worked first time.

    Before I start describing what I did and how, I'm letting you know in
    advance that I'm not going to tell you which specific components to buy,
    since your electronics store is not likely to have the same components
    which would make it hard for you to figure out what would be a solid alternative if you didn't understand the how and why of it all.

    So, disclaimer out of the way, my aim was to build a crystal radio using
    off the shelf components without needing to steal a razor blade, shave a
    cat, sharpen a pencil or any number of other weird contraptions. Not that
    those aren't potentially interesting as life pursuits, though the cats I
    know might object strongly, I wanted this to be about learning how this
    thing actually works without distraction.

    I set about finding a capacitor and an inductor combination that made a resonant circuit with a frequency range that falls within the AM broadcast band. If you recall, you can make a high-pass filter from either a
    capacitor or an inductor. Similarly, you can make a low-pass filter from
    either component. If you line up their characteristics just so, you'll end
    up with a band-pass filter that lets the AM broadcast band pass through.

    Now notice that I said range.

    That means that there needs to be something that you can adjust.

    In our case you can either adjust the inductor, or the capacitor,
    technically you could do both. My electronics store doesn't have variable inductors, so I opted for a variable capacitor.

    The challenge becomes, which variable capacitor do you select with which inductor?

    I used a spreadsheet to show what the bottom and the top range for each capacitor would be if combined with each inductor. This gave me a table
    showing a couple of combinations that gave me a range of resonance inside
    the AM band.

    The formula you're looking for is the resonant frequency for a parallel LC circuit. Take the inductance and multiply that by the capacitance, then
    take the square root, multiply it by pi and again by two, then take the
    inverse and you'll have the resonant frequency. You'll need to pay
    attention to microhenry vs millihenry, and picofarad vs nanofarad and
    you'll also need to confirm that you've got kHz, MHz or just Hz out the
    other end, otherwise you'll end up several orders of magnitude in the wrong spot.

    If you do all that, you'll likely end up with a couple combinations of
    inductor and capacitor that will do what you want.

    Then when you head to the electronics store, you'll find that the stock
    you're looking for is end-of-life and that the colour coding on them isn't right, but if you manage to navigate that swamp, you'll come out the other
    end with a few parts in your hands.

    Final bit you'll need is a diode. It acts as a so-called envelope detector.
    I'm not getting into it here, I'll leave that for another time, but a
    Schottky or Germanium diode is likely going to give you the best results
    for this experiment.

    Wiring this contraption is pretty trivial. Start with joining the inductor
    and capacitor to each other in parallel, they'll act as the LC circuit. You
    can change the resonance by tweaking the variable capacitor. Then attach a
    long antenna wire to one end and an earth wire to the other end. Finally, connect the diode and an amplified loudspeaker in series between the LC
    antenna end and the LC earth end and your radio is done.

    For my experiment the loudspeaker has a built-in amplifier, it's an
    external PC speaker with a power supply. I also had to keep my hand on the antenna to create enough signal - since essentially I'm a large body of
    water - great for being a surrogate antenna.

    The unexpected thrill of hearing a local announcer coming through into my
    shack from three components lying on my desk was worth the anticipation.
    Highly recommended.

    What are you waiting for?

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201108.foundations-of-amateur-radio.mp3

    The excitement is palpable ...

    Posted: 31 Oct 2020 09:00 AM PDT

    Foundations of Amateur Radio

    I'm looking at components. Not looking for, looking at. I have them sitting
    on the bench in front of me. A collection of six variable capacitors and
    six inductors. There's also a germanium diode, a breadboard, some
    connecting wires and two connectors.

    I don't quite need that many capacitors or inductors and truth be told a breadboard is overkill, but I found myself getting into the spirit of
    things and for the tiny investment it seems like the thing to get whilst
    you're dipping your toe into the art of electronic circuit prototyping.

    I am noticing something odd whilst I'm looking at these components, a
    familiar feeling in some ways, butterflies in my stomach. It's the exact
    same feeling as when I sit at the radio, getting ready to speak into the microphone just as I am starting a weekly radio net, something that I've
    now done about 480 times, not to mention the times when I did around 1600 interviews or broadcast live to the world, butterflies.

    I'm mentioning this because in many ways this is a momentous event, not for
    the world, not for humanity, not even for the hobby, but for me. It's the
    first time I'm building a circuit completely from scratch, no pre-made
    circuit board, no pre-selected components, no building instructions, just
    me, some resonance formulas and the hope that I've understood what they represent and that the components I selected will do what my calculations
    say they should.

    To make this even less exciting, there's no external power, nothing that's going to go boom or let magic smoke escape, nothing that will break if I
    get it wrong, but still.

    The other day I received an email from Phil, WF3W. We have been exchanging email for a couple of years now. He's a member of the Mt Airy VHF Radio
    Club in Pennsylvania in the United States.

    His email outlined an interesting question. What do new amateurs get
    excited about in this era of the ubiquitous world wide web? As a hobby
    we're attracting new members every day. Many of those are coming to the community by way of social media, rather than using things that are more traditionally considered radio like HF DX, making long distance contact
    using HF radio, rather than exchanging pithy emails or instant messages via
    the interconnectedness of the globe encompassing behemoth of the Internet.

    The answer came easily to me, since last week we had a new amateur, Dave
    VK6DM who made his very first long distance HF contact between Australia
    and the United States. His level of excitement was contagious and that's something that I've found happens regularly.

    Someone talks about magnetic loop antennas and the next thing six amateurs
    are building them. One person starts playing with satellites and before you know it YAGIs are being built and people are describing their adventures.

    The same is true with my crystal radio. I've talked about it a couple of
    times and people are digging out their old kits and telling stories about
    how they grew up with their dad making a crystal radio.

    That's what is exciting the new amateurs. The internet is just an excuse to find each other, just like F-troop is an excuse for people to turn on their communications tool of choice at midnight UTC on a Saturday morning to talk about amateur radio for an hour.

    My excitement comes from trying new things and just like keying a
    microphone for the first time, there's this almost visceral experience of anticipation associated with starting.

    I'm still working out how I want to build my new toy and how to go about testing to see if it actually works and what to look for if it doesn't. I'm trying hard to resist tooling up with crazy tools like signal generators
    and oscilloscopes, instead opting to use things I already have, like LC
    meters and my ears.

    I can't wait until I can share how it goes.

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201101.foundations-of-amateur-radio.mp3

    Antenna testing in the field.

    Posted: 24 Oct 2020 09:00 AM PDT

    Foundations of Amateur Radio

    Antenna testing in the field.

    If you've been around amateur radio for any time at all, you'll know that
    we spend an awful lot of time talking about antennas. How they work, where
    to get them, how to build them, how strong they are, how cheap they are,
    how effective, how resonant, you name it, we have a discussion about it.

    It might not be immediately obvious why this is the case. An antenna is an antenna, right?

    Well ... no.

    Just like the infinite variety of cars on the road, the unending choice of mobile phones, ways to cook an egg and clothes to wear to avoid getting
    wet, antennas are designed and built for a specific purpose. I've talked at length about these variations, but in summary we can alter the dimensions
    to alter characteristics like frequency responsiveness, gain, weight, cost
    and a myriad of other parameters.

    If we take a step back and look at two antennas, let's say a vertical and a horizontal dipole, we immediately see that the antennas are physically different, even if they're intended for exactly the same frequency range. Leaving cost and construction aside, how do you compare these two antennas
    in a meaningful way?

    In the past I've suggested that you use a coax switch, a device that allows
    you to switch between two connectors and feed one or the other into your

    If you do this, you can select first one antenna, then the other and listen
    to their differences. If the difference is large enough, you'll be able to
    hear and some of the time it's absolutely obvious how they differ. You
    might find that a station on the other side of the planet is much stronger
    on one antenna than on the other, or that the noise level on one is much
    higher than the other. Based on the one measurement you might come to the conclusion that one antenna is "better" than the other.

    If you did come to this conclusion, I can almost guarantee that you're

    Why can I say this?

    Because one of the aspects of the better antenna is dependent on something
    that you cannot control, the ionosphere, and it is changing all the time.

    I have previously suggested that you listen to your antenna over the length
    of a day and notice how things change, but that is both time consuming and
    not very repeatable, nor does it give you anything but a fuzzy warm
    feeling, rather than an at least passing scientific comparison.

    A much more effective way is to set up your station, configure it to
    monitor WSPR, or Weak Signal Propagation Reporter transmissions using one antenna, for say a week, then doing it again with the other antenna.

    If you do this for long enough you can gather actual meaningful data to determine how your antenna performs during different conditions. You can
    use that knowledge to make more reliable choices when you're attempting to
    make contact with a rare station, or when it's 2 o'clock in the morning and you're trying to get another multiplier for the current contest.

    You don't even have to do anything different and spend little or no money
    on the testing and data gathering.

    You can do this with your normal radio and your computer running WSJT-X, or with a single board computer like a raspberry pi and an external DVB-T
    tuner, a so-called RTL-SDR dongle, or with an all-in-one ready-made piece
    of hardware that integrates all of this into a single circuit board.

    If you want to get really fancy, you can even use automatic antenna
    switching to change antennas multiple times an hour and see in real-time
    what is going on.

    You also don't have to wait until you have two antennas to compare. You can
    do this on a field day when you get together with friends who bring their
    own contraptions to the party.

    If there's any doubt in your mind, you can start with a piece of wire
    sticking out the back of a dongle. I know, I'm looking at one right now.
    I've been receiving stations across the planet.

    One thing I can guarantee is that the more you do this, the better you'll
    get a feel for how the bands change over time and how to go about selecting
    the right antenna for the job at the time.

    I'm Onno VK6FLAB
    This posting includes a media file: http://podcasts.itmaze.com.au/foundations/20201025.foundations-of-amateur-radio.mp3

    The making of a Crystal Radio

    Posted: 17 Oct 2020 09:00 AM PDT

    Foundations of Amateur Radio

    Recently I made a commitment to building a crystal radio. That started a fevered discussion with several people who provided many helpful
    suggestions. This is the first time I'm building a crystal radio and to
    make things interesting I'm selecting my own components, and circuit
    diagram. What could possibly go wrong?

    Crystal radios have been around for a while. Around 1894 Indian physicist Jagadish Chandra Bose was the first to use a crystal as a radio wave
    detector, using galena detectors to receive microwaves. He patented this in 1901. The advice I was given sometimes feels like it harks back to 1894,
    with suggestions of using cats whiskers, razor blades, and any number of
    other techniques that create the various components to make a so-called
    simple crystal radio.

    At the other end of the scale there were suggestions to go to the local electronics store and buy a kit.

    The first suggestions, rebuilding historic radios from parts made of
    unobtanium would mean many hours of yak shaving, just to get to the point
    of getting the components, rather than actually building the radio.

    I realise that part of the experience is the journey and I'm sure that if
    my current project gets me hooked I'll look into it, but I really don't
    want to become that amateur who has a collection of home-brew crystal

    [continued in next message]

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