Owning A ShortWave Radio Is Once Again A Subversive Activity

An abiding memory for a teen fascinated by electronics and radio in the 1970s and 1980s is the proliferation of propaganda stations that covered the shortwave spectrum. Some of them were slightly surreal such as Albania’s Radio Tirana which would proudly inform 1980s Western Europe that every village in the country now possessed a telephone, but most stations were the more mainstream ideological gladiating of Voice of America and Radio Moscow.

It’s a long-gone era as the Cold War is a distant memory and citizens East and West get their info from the Internet, but perhaps there’s an echo of those times following the invasion of the Ukraine. With most external news agencies thrown out of Russia and their websites blocked, international broadcasters are launching new shortwave services to get the news through. Owning a shortwave radio in Russia may once again be a subversive activity. Let’s build one!

Whatever Happened To The Portable Radio?

A typical small world band radio.
A typical small world band radio. Donald Trung Quoc Don (Chữ Hán: 徵國單) CC BY-SA 4.0 International.

There was a time when everyone had a radio, and radio listening was a universal occupation. From 1930s families clustered round an ornate family radio to the teenagers of the 1960s and 1970s with their portables, it’s a defining 20th century image. Though many of us still listen to radio here in 2022 the chances are that we no longer do so over AM and certainly not over shortwave. We can get instant access to almost any content online, so it’s by no means certain people will have a radio. If those shortwave transmissions are starting again, how can their intended audience pick them up? Perhaps it’s time to look at shortwave radios with a 2022 slant.

If you lack a shortwave radio and a dig around all your family’s junk hasn’t turned up a relic from decades past, then the simplest way to get one is of course to buy one. AliExpress is full of “world band” radios starting from somewhere under $20, and if you don’t mind waiting for shipping from China then it’s the path of least resistance.

But there’s the problem, international events are moving fast and there might not be the luxury of waiting three weeks, or even for that matter of being able to order one at all in a warzone. How can you make one? Yet again there’s an extremely simple option in the Silicon Labs series of one-chip radios. These provide a high-performance shortwave receiver with a minimum of external parts, and really are a miracle of integration. But yet again, in a warzone and in the middle of a chip shortage they just might not be an option. So how can you make a shortwave radio receiver using what parts might be at hand from available consumer electronics? We’ll first be taking a look at some possible avenues, and then introducing a few of the readily available building blocks.

Where Do You Start?

The best way to start is to look at the things that you might already have. Such electronic flotsam and jetsam as battery-powered AM radios, car radios, or even $10 RTL-SDR sticks. All of these can be modified or converted to receive the shortwave broadcast bands, often with readily available parts.

Probably the simplest method possible might be to directly modify an existing AM radio. I’m indebted to [Phil M6IPX] for passing me on an instructables link for a method to do this. It involves changing the resonant frequency of the ferrite rod antenna coil in the radio, and I’m guessing, relying on a harmonic of the local oscillator father than the fundamental to do the mixing. It doesn’t cover all the broadcast bands, but it might do at a pinch.

Block diagram of a receive converter
Block diagram of a receive converter

The next method lies in converting the shortwave signal from its original frequency to one that can be received by a radio you already have. Radio amateurs will be familiar with the receive converter, a device that mixes the signal from an antenna with a fixed frequency local oscillator to produce an intermediate frequency of their difference, and it should be relatively straightforward to use this technique.

An AM radio tunes in around 1 MHz and can be used with a converter to cover just one of the many shortwave broadcast bands. [Phil] again suggested a 16 MHz crystal oscillator module might be used with a mixer to tune the 15 MHz (19 m) broadcast band onto an AM radio, and a commonly available 4.433 MHz PAL colourburst crystal with a simple transistor oscillator might do the same for the 5 MHz (60 m) band. If I were making such a rough-and-ready converter for an AM radio, I’d try to find a car AM radio to serve as my IF, because these radios are well screened and have a handy co-axial antenna input.

My one-inch converter PCB
My one-inch converter PCB

Meanwhile an RTL-SDR can be modified for shortwave reception by either modification or by using a converter. The direct sampling hack bypasses the onboard tuner chip to pipe signals directly to the SDR chip and can be performed by anyone with good SMD soldering skills, and for those unwilling to try it an alternative approach is to use a converter with a 50 MHz oscillator.  A few years ago I produced such a converter using a CMOS chip as my entry in the Hackaday Square Inch competition, but there are even simpler circuits to be found.

Finally, perhaps the simplest usable shortwave radio is the direct conversion receiver. Its principle is similar to the receive converter in that the signal from the antenna is mixed with that from an oscillator to yield the difference between the two, and when the local oscillator is the same frequency as the desired station that difference can be fed to an audio amplifier and listened to. It requires three relatively simple circuits in oscillator, mixer, and audio amplifier, and while it doesn’t provide acceptable performance for music radio it’s fine for speech.

The Nitty Gritty: Parts And Circuits

Having fired everyone up about receive converters and direct conversion receivers, it’s time to take a look at those building blocks. How can you make them from the components you’ll find in electronic junk, without ready access to the global electronic parts supply chain?

There are many ways to make oscillators and mixers, but for our purposes the components we are interested in are crystal oscillator modules for the local oscillator, wideband RF transformers for the RF coupling, and diodes as the mixer elements. Variable frequency oscillators are a little more tricky to build but can be made from the most basic of components, but if you have a signal generator or even a Raspberry Pi with appropriate software you can use them instead.

Crystal oscillators are ubiquitous on all sorts of PC expansion cards and other computer boards, and provide a logic-level squarewave on their output pin when provided with 5 V. Meanwhile any Fast Ethernet interface will contain an RF transformer, and small signal diodes can be found across multiple different types of electronics. Beyond these parts there may be a need for the normal discrete components such as transistors and passives, but yet again these can be scavenged from a wide variety of sources.

A diode ring mixer circuit
This is the basic made-from-junk diode ring mixer. It’s not perfect, but it works.

A diode ring mixer is a very straightforward circuit using a couple of RF transformers and four diodes. It works by using the diodes as switches operating at the local oscillator frequency to alternately pass and block the signal frequency. The result is the intermediate frequency (IF), which is the difference between the incoming signal and the local oscillator. It can be very easily made with an Ethernet transformer and four signal diodes using the circuit shown. With a 100 Mbit Ethernet transformer, it should have 100 MHz bandwidth. There are multiple ways in which this circuit can be used with a suitable oscillator as either a receive converter for an AM radio or as a direct conversion receiver.

For the converter, simply connect the output of a crystal oscillator module to the local oscillator pin and feed the output to an AM radio, while for a direct conversion use a variable oscillator and connect the output to a sensitive audio amplifier such as a microphone or phono amplifier. The coupling to the AM radio can either be direct to the antenna socket of a car radio, or via several turns of wire wrapped round the case of a portable AM radio. There is a problem with this circuit in that it has no filtering and thus picks up both both the sum and the difference of local oscillator and IF frequencies, but it should be good enough to pull in a shortwave broadcast.

These are not the only ways to make a working shortwave receiver — after all everything from a crystal set upwards can be coaxed into working — but we think they are probably the best ways to make one using the electronics likely to be at hand. Perhaps you have some ideas to add to the mix? Leave them in the comments!

136 thoughts on “Owning A ShortWave Radio Is Once Again A Subversive Activity

  1. The numbers stations that were common on the HF bands during the cold war seem to have been resurrected, according to a couple of posts I’ve seen to the ham radio mailing lists.

    1. I am a ham radio operator & became interested in short wave stations back in 1959! The VOA & BBC are ramping up their Russian language broadcasts. But they need to broadcast on European long wave frequencies as well a short wave frequencies. They should also set up transmitters in Eastern Poland, Romania, Lithuania & Funland to broadcast on FM frequencies. This should saturate Russia with the truth. Long live Ukraine!

        1. Directional antennas and QRM eliminators can help a lot with reducing interference.
          I’m suffering from badly installed solar panels in the neighborhood which jam a LOT of radio stations, but with a phasing QRM eliminator i get a dramatic reduction in interference.

        1. Sure? I was sure there are only few regional initiatives on MW in poland. Polskie Radio officially resigned from MW but is still active on SW. Not sure where is transmitter. I just started with radios few days ago because I am sure that sooner or later this will become handy again. I just hope this will become my hobby not necessity.

      1. Maybe because I’m old school, but I’d be building a Regen receiver. I built them with 1T4 tubes when I was around 12 over 60 years ago way before I got my ham license. I have a substantial supply of 2N3904’s for building things, but many others including 2N2222 that some people like will also work. Small cheap tuning caps are on eBay along with anything else needed. The same transistor can also be used as an audio amplifier if you don’t want to use headphones. Circuit diagrams are everywhere on the web.

        1. You bring back memories by mentioning 1T4. The first radio I repaired had the 1 series of tubes. Portable, two batteries one for the filaments, one for B+. Don’t recall the brand.

    2. I was an avid shortwave listener back in the 70s when I was kid. CB radio & I wanted become a ham as well. Learning Morse Code was something I could not do on my own but I really wanted to learn it. A guy I knew from the CB was a Morse Code Intercept Operator in the Army Security Agency in Vietnam. He told me stuff he probably shouldn’t have. I was hooked. When I was 17 I joined the Army & for the same job. I graduated the school & the govt paid me to do my hobby. I loved it. Did it for 13 years. I have purged most of the classified data from my brain but I can still listen to signals & know who they belong to. I last did that job about 30 years ago & in some matters, somethings have not changed. I am well aware of how much technology has come. Going from copying Morse Code on mills (all cap typewriters) & spinning the heavy knob of an R-390A tube receiver to SDR & decoding software. It’s really amazing.

      1. My father was ham as were all his friends. Hw was a member of M.A.R.S. He had teletype machines and loved to do phone patch. He had illegal phones from his buddies and one day the sheriff with Ohio Bell reps came to the house to confiscate his army phone and no sooner did they leave he had another one setup. I remember setting up a packet RTTY BBS for him. He was a heathkit fanatic and so was I. First radio I built was a crystal set. I can still see the big copper coil.

        To this day I still have difficulty understanding how we transitioned from vacuum tubes to solid state? How did it happen? That was a paradigm shift in my mind.

      2. Great story, Ralph! I was a SWL first, then licensed as a ham in 1990 and enlisted in the Navy as an ET. Out of the thousands of Navy “C” schools, I was lucky enough to be sent to HF amplifier/transmitter school and then to USS Gonzalez, a guided missile destroyer. It’s a real gift when your hobby dovetails with your career! Thanks for your service.

    3. Instead of special mixer transformers, the baluns from 300-to-75 ohm TV set antenna adapters/connectors can be used when wired together. Not all have a center tap on both sides, so use the CT’d side for the diodes hookup. 1N4148 diodes can be salvaged from many broken/old ‘simple’ electronics items that uses a microprocessor. The diodes may be found around switch keypads and i/o pin circuits. As mentioned, xrystal oscillators can be had from many old junks.

    4. I just got back into the hobby. It’s very easy to find Numbers Stations. Priyom.org go to Station List (or words to that effect) its a dynamic dashboard of active Numbers Stations. It also intrigates with websdr. With this tool I listened to more Numbers Stations in a 12 hour period than ever. That said there are fewer Numbers Stations than just 10 years ago.

  2. Weren’t there radios in Soviet Russia that weren’t? More an amplifier fed over wire from the broadcaster. I may be misremembering. But it sure keeps out other countries.

    1. These non-radios certainly existed here in the Netherlands. It was called “draadomroep” (line broadcast) and was a much cheaper alternative to a real radio with a limited number of channels (IIRC 4 or 5). I’m pretty sure similar systems existed elsewhere too

        1. It’s easier to control the messages today, with the propagandists controlling big tech and the media companies. Ham may be the only source of unfiltered information left

          1. Unfortunately a number of HAms themselves at least in Australia are the protagonists of miss information. Politics is alive and well on the air here. And God help you if you disagree with the establishment.

        1. I gather there was early broadcast with a wired system, before radio. Ihad no idea it happened elsewhere later.

          But if you have a closed system the public can’t tune the band and hear foreign stations.

          Ham radio was allowed in the USSR, but the articles in North America suggested it was controlled, and maybe used as a tool of propaganda, rather than rather than how we experienced it elsewhere. Like a lot of things, radio came with the USSR, rather than existing much before that.

          1. I use to “talk” (CW only) to the Soviet Union from around 1983-1985 with amateurs radio using a 1960s heathkit DX40 AM/CW transmitter and a Kenwood R-600 shortwave receiver. I was in SF Bay Area so skipping signals to Vladivostok was fairly easy. They tended to have “chirpy” cw signals due to their self admission that they were using homebrew equipment. My memory was that almost all of the said their equipment was homebrew. Ironically, my transmitter was out of calibration and also sounded “chirpy” leading some to believe I was in the Soviet Union until they got my full call sign. Conversations were are very simple of course, gear, weather….nothing political or edgy since we all understood the circumstances.

          2. USSR era hams were first ‘trained’ as SWLs (shortwave listeners) and therefore could not make any transmissions. Just reception only and the trainee had to be of ‘good standing’ in the communist party. Any infractions and you were allowed in. After a certain time or proven ability to use a shortwave receiver you were advanced to a ham trainee… Most USSR Morse Code operators were very good at sending and receiving code. Because USSR was basically poor in stores etc, USSR hams had to improvise and make many of their own parts and devices. Most USSR hams ran a homebrew (from scratch) station, using a vertical antenna and anywhere from 20 to 100 watts to the antenna. Their mode of operation was Morse Code due to the simplicity of building their own tranmitter and their lack of available parts. During the Cold War USSR had a Moscow mail-box and it was simply ‘Box 88, Moscow USSR.’ All QSL (verification cards) were mailed through that one address. Mail was censored at Box 88. During Christian Holiday times, the USSR ops only said “Season’s Greeting.” No happy Easter, no merry Christmas etc.

      1. I know this is not related but “draadomroep” to me looks like “draad on rope” as an English speaker, and “on rope” could be similar to “on line” in English, so considering you speak both English and Dutch am I on to something, is “draadomroep” a combination word meaning “Broadcast/Transmission/Station on Line” or am I just seeing things?

        1. The Dutch word just explains what it does. Draad–> equals line or wire in English—–> Om–> this is a prefix which means around or about—> roep (the noun call) comes from the Dutch verb “roepen”, this means in English “to call”..so, litterally word for word “Line or wire around or about call or calling”,,,ohh Ja, then in English we get broad-cast. German is fun too very similiar to Dutch only it’s Drahtfunk,,,wire funking just kidding Wire Radio. Ja zee the Germanic languages.

          1. Oh, I see. I guess in English is could be “Call on Line”. I just wonder because English, although a Germanic Language, uses a lot of Latin Vocab. so sometimes I see words in other Germanic languages and think, “Hey that looks sort of familiar.” Funk has a completely different meaning in English, so it’s funny to see Rundfunk. (And not to mention Swedish Fart or German Kunst!)

    2. In Germany, we had “Drahtfunk” (wire radio). Must have been in the 60s or so.
      The “radio” merely was a speaker with a volume knob.
      It connected to a box down on the wall that had a channel switch (3 channels) and two banana plug ports for the speaker’s banana plugs.

    3. Yes, it was called ‘Radiotoschka’. Most networks were shut down just a few years ago. If you do a youtube search on the cyrillic spelling of the word, you can find some stuff about it. There was actually a belarussian news bulletin about how sad some old folks were that it was shut down, but it seems to have been blocked/removed: https://www.youtube.com/results?search_query=%D0%A0%D0%B0%D0%B4%D0%B8%D0%BE%D0%A2%D0%BE%D1%87%D0%BA%D0%B0
      IDK if the comment system here renders the cyrillic properly.
      The radiotoshka (radio box) could only play the main public broadcast station.

      In the Netherlands we had a choice of 4 stations for our wired radio system. It was popular because it was cheap, the quality was higher too. I still have 2 radio distribution speakers, they are excellent Peermans units.

    4. There was also a service in Italy, called “Filodiffusione”, there were the 3 public broadcast radio channels and two extra channels, one only classical and opera and the other only pop/rock. It worked sending AM stereo signals on the 150-300 kHz range. You could use either a dedicate receiver like the one above or a regular long wave receiver to listen to it.

      The system was of course not compatible with ADSL, so was ended when DSL services were introduced, and these programmes were broadcasted with an interet streaming service.

    5. Poland had those wired radios during and after WWII. Nazis used them to broadcast propaganda (because they confiscated all privately owned radio receivers they could find), then soviets took them over and piped their propaganda. Interestingly the system used high voltage audio signals and the end user or public place would have a speaker with transformer. These systems didn’t last long as soon after the war Polish Radio resumed operation.

      I have somewhere a book from 1950’s that taught basics and history of electricity and radio. It also taught kids how to make a simple dual triode radio receiver. It also featured quite a lot of quotes and letters from Marx, Engels and Lenin.

    6. I have a couple of those “non radios” from russia, I was thinking about setting them up on a local net somehow and play russian propaganda on the lokal net, but I never found any info on what voltage and how the program was overlayed, so they are just collecting dust.

      The fun thing is there is no off switch on the volume, according to an old russian guy I was talking to there was only “Low to high” on the volume on certain models so it was spewing propaganda 24/7
      And there was a rumour that if you pulled the plug, it was detected and you might get a visit from some guys in leather coats.
      There were also rumours about microphones built into them, might be true, I haven’t opened mine yet since it is sealed with melted plastic over the screws. Hmm?
      Probably not true that you werent allowed to unplug it, but many people didn’t dare to pull the plug so they put the winter hat over it to mute it.

    7. Yeah, eBay is full of them these days, e.g. https://www.ebay.co.uk/itm/324676940495. When you see then with the back off there’s just a speaker and a bit of switchgear (presumably for changing ‘stations’) to be seen.

      Some of them are really nice-looking… I’ve often thought if shipping and customs wasn’t so expensive I’d have one to make into a Bluetooth boombox.

  3. There were number stations operating last year.
    I’ve got a few receivers, sometimes I like to decode the Morse and data signals or just leave them on as background noise in my workshop.

  4. You are a wonderful spokesperson for your point of view. Thank you.

    Numbers stations never went away.

    AM radios can be fiddled with by adjusting the coils in square cans with SCREWHEADS in the top for tuning.

  5. “Finally, perhaps the simplest usable shortwave radio is the direct conversion receiver.”

    True. That and the Audion radio receiver.
    The audion could also be backfed, so it would be able to detect CW and SSB signals (“Rückkopplungsaudion” in German).

    Then, there also was the “Pendelaudion” (German term).
    The English term was “regenerative receiver” I suppose.

    Alternatively, a classic AM receiver with an BFO (beat frequency oscillator) could be used.
    BFOs could easily be installed in existing AM radios.

    FM could always be received by AM receivers, also.
    Going a bit beside the center frequency was all that’s needed.
    Due to its selectively, the AM circuit was able to do that.
    Even crystal receivers (detector radios) had this ability.

    Speaking of the DC receiver..
    In the 2000s, before being spoiled with commercial SDRs, “we” used the DREAM and SDRadio programs to demodulate signals that we received with a homebrew DC receiver and a soundcard (line-in recommended).

    An IF of 7 KHz to 12 KHz was good enough for receiving Dogital Radio Mondiale (DRM)..

    And with a sound card that had 192KHz sampling rate, it was possible to receive VLF directly sometimes.

    German book author Mr. Kainka had schematics on his site. Some used tubes, even, which were robust enough to handle strong signals coming from the longwire antenna.

      1. Hi Jenny,
        Since I am not able to do these things, is there a few radios (NOT JUNK) that you can advise? Year’s and forever ago I owned an old bulbs in Transoceanic, Zenith I think. It was MARVELOUS! Appreciate your help.

          1. I have a sony,PLL SYNTHESIZED RECIEVER ICF-2001D, It has AIR,FM,LW,MW,SW, With upper+lower sidebands,had it since new,external anntenna possible also, will i be able to pick up long distance over SW?.Thankyou.Rob

          2. I just returned a Tecsun PL-990. Had a lot of great features, but the antenna jack is one of those junk 1/8th” jacks setups. I strung it up, but couldn’t receive WWV in NJ at 9 or ten PM.
            Brought it downstairs and clipped the centerline from my “junk” dipole, which works perfectly fine on a genuine old Grundig Sattelit 800, and STILL NOTHING.
            By the way, switching antennas to the grundig, it came in loud and clear.

            Nothing even from 5085 at those same times, while Grundig pulled it all in loud and clear (well, as clear as you’d expect).

            Either I got a bad one, and it was new in the box, or they’re junk. For the almost $300 i spent on it, it just went back after 1 week.

        1. I had Zenith Yranoceanic in 1968 and it was fantastic. I had come just recently from india and was very fond of a radio program called Bina a Geetmala from Radio Ceylon. At 8 am I will turn it on for 30 broadcast every Wednesday and put the phone ext to it so my friend can listen to it who was 5 miles away! Fond memories. Phone calls were $5 per minute. Now zero with WhatsApp!

        2. @Paco said: “Hi Jenny, Since I am not able to do these things, is there a few radios (NOT JUNK) that you can advise? Year’s and forever ago I owned an old bulbs in Transoceanic, Zenith I think. It was MARVELOUS! Appreciate your help.”

          Hello Paco. These little AM-FM-SW-MW AM/FM/SSB receivers from China look pretty good for the money. They use an Arduino Nano microcontroller board (included) that sit on the radio’s main board running open source firmware.[1] You can buy these radios on Amazon for around $59.99 [2], they’re also on the Chinese sites like Banggood and Aliexpress. Since you will be hacking this radio to constantly improve it, you really should be somewhat technically inclined, especially when it comes to uploading firmware to an Arduino board using something like the Arduino IDE. Sometimes these radios are called “ATS-20” because some bear this part number.

          These receivers use Software Defined Radio (SDR) chips originally made by Silicon Laboratories (SiLabs) that are now made by Skyworks. The ads say the radios use the Si4732 chip, but that’s a rather old chip, and like everything else these days they are perpetually out of stock. Today the radios might be using Chinese clone Si4732 chips. You can learn more about these chips by looking at the datasheet from a newer part like the Si4734/5.[3] There’s probably a user’s group for these radios on the likes of groups.io, ask around. There are plenty of YouTube videos about these radios too, search for them.[4]

          This is an interesting radio, especially if you are technically minded. All sorts of modifications and firmware updates are available for them, and they keep on coming.

          1. Link to the radio’s open-source firmware:


          2. ANYSECU SI4732 Shortwave AM FM Radio AIR Band DSP Full Band (MW & SW) SSB (LSB & USB) Scanner Portable Radio $59.99


          3. Si4734/35 AM/FM/SW/LW Radio Receivers


          4. And here’s the obligatory YouTube video review. There are lots more on YouTube:

          Si4732 Radio Sketch Updates 2.3.09 [08:17]


      2. Hi, no no, I’m afraid you got me wrong. What I wrote wasn’t meant as criticism. 🙂 Direct conversation receivers follow the same principles, after all.

        They’re from a time when people didn’t absolutely needed superhets, double superhets or tripple superhets.

        Using a sinple design has some advantages, also. The self-noise of transistors are a problem in such easily overengineered designs. In the end, a superhet with, say, 20 transistors becomes less and less sensitive due to noise than a quality crystal radio, making things lead ad absurdum.

        Going mentally past the superheterodyne is the best that happend to the amateur radio scene in the past few years, I think.

        A DC receiver also has the advantage that it is able to receive a signal without much alteration – it thus can easily be demodulated in software afterwards*.

        (*Technically also possible through tapping the IF of a conventional receiver. But when homebrewing, why not simply build a DC receiver instead?)

  6. Wow that took me back. I remember picking up Albania on the first electronic thing I made – a crystal set – aged around 12, late 1970s UK, seemed close to magic at the time.

    1. Anyone in the UK remember “The Bedford Radio Exchange”. As an almost-teen I built a couple of their kits under my father’s supervision. I didn’t know about shortwave, but was fascinated by the prospect of being able to listen to TV audio after bedtime.

  7. An abiding memory for a teen fascinated by electronics and radio in the 1970s and 1980s is the proliferation of propaganda stations that covered the shortwave spectrum.

    I had an antique floor standing radio as a youth in the 80s. The only specific think I recall hearing was a story on Radio Moscow about a Soviet ships’ crew rescuing some stranded Americans. It ended with a hokey, “both crews agreed that peace in the world and between their countries was desirable.”

    1. Radio Moscow, and Radio Havana were hysterical. Moscow used to have a program where non-Russians wrote in asking questions about Russian life.

      I remember someone writing in, asking if Russians had cars. The response was something like “Of course Russians had cars. They’re good cars, built with Russian engineering and technology. Not like those American models that broke down constantly.

      The propaganda was great.

  8. I was 14 in 1974 and had just built a Heathkit short wave receiver and heard the radio announcement, “There’s trouble on the island of Cyprus”. It was the Turkish invasion of Cyprus and the local US news barely covered it. I was fascinated!

  9. Painfully relevant music video by (east) German band Rammstein from : “Radio” – https://youtu.be/m6UNdY0xadQ (With english lyrics)
    The name and electronic music parts can be seen as an homage to Kraftwerk’s “Radioaktivität” (the earlier/earliest(?) version which wasn’t so much about nuclear radioactivity, more the literal “radio activity”).

    1. Good song, and good comment!

      Directly related: I’m glad I held on to my RTL-SDR and upconverter setup after I was done experimenting with it. Seems like I have a good use for it again.

      Peripherally related: I made my wife laugh a few times by badly lip syncing the chorus of “Radio” at her while holding the microphone of my ham radio transceiver (not transmitting, of course).

      1. I have a few RTL- DVBx dongles but never took the time to actually “built” a RTL-SDR setup (software, hardware, ++) :-/
        But it is on my list… and there is so much stuff I’d want to play around with (TETRA, old garga door openers – to show people how terrible those are RF-wise, and whatnot).

  10. I’ve been wrangling radios since the 1960s & caution that rustled up Short Wave circuitry can lead to much frustration… Consider such factors as –
    * Band interference -both natural (distant lightning etc) & man made (jamming,electrical noise etc)
    *Propagation variance -daily, seasonal & sun spot related.
    * VERY weak signals -often VERY long receiving antenna may be needed.
    * Tuning -stations may be so close together during band openings that finding/resolving them can be frustrating. A digital freq. display is near essential !
    * Reception mode -radio hams & utilities have long used SSB (Single Side Band) requiring a receiver BFO for voice “decoding”.
    * Digital mode data “flea power” transmissions are common-WSPR etc.
    * Non terrestrial “radio ftom space” satellite based setups are increasingly available.

    73s -Stan. (ZL2APS – since 1967)

    1. Same here, and completely understood.

      I find a simple mixer-as-front-end direct conversion receiver to be amazingly good though, it’s what I’ve settled on for my own designs.

      I hope using an AM car radio as an IF with a converter will solve a lot of issues. However it won’t solve the issue of image rejection with the circuit shown above, though it should be adequate for a broadcast station.

  11. A few years ago I tried to build a crystal set for shortwave; I had the naive idea that by taking a common design and changing the resonant frequency (using an online coil calculator) that I’d be able to aim at 5MHz and pick up WWV. Got swamped by local AM stations, of course, though oddly if I hooked a small audio amplifier to the output, it instead got swamped by a local _FM_ station.

    1. I tried this last week, with a super regenerative receiver setup, and wowie is it a hassle to tune. The induced capacitance of my hands near the antenna seems to swamp the adjustable cap in the antenna resonator section.

    2. Sure, because nothing’s evolved since Armstrong patented the regen in 1914. Even the superhet was patented in 1920.

      The anti-technology of ham radio is incredible

      1. Ham radio is the art of the possible, not the prowess of bleeding edge technologies. Can we build a better radio? Sure. But there are often features of older designs that may have been overlooked, or perhaps improved quite a bit with newer parts and materials.

        There is nothing wrong with exploring an old design of using a regenerative radio with modern parts. It is no more wrong than riding a horse instead of driving a car. Some people just want to prove that it can be done.

        That said, if I were trying to build a functional receiver, I don’t know if I would have chosen a design of that sort. At the very least, I’d substitute an FET for the tube. But if you’re just playing, who cares?

      2. My point of view: Radio amateurs were computer pioneers in the 1970s/80s. Lots of TTL circuits they built. The first (?) commercial digital SSTV Scan Converter, the Robot Model 400, was made by amateur radio company. Just to name a single example. SSTV was also used by non-hams via telephone line.

        It’s just *seems* that today’s radio amateurs nolonger homebrew the way they used to. The youngs amateurs either do use commercial modules/kits or are fascinated by telegraphy/shortwave.

        Their fascination perhaps comes from the “analog” shortwave being so alien to them, since they grew up with the internet.

        So they are fascinated by telegraphy, but not modern digital speech codecs, APRS, or satellite communication. No, those things are not very interesting to them, because they are too similar to modern communications they’ve used to. Heck, they don’t even like to use elbugs for telegraphy. Too modern, perhaps?
        – Yes, that’s really sad indeed. Amateur radio is so much more than contesting, FT and telegraphy. It’s about learning, experimenting, creating independent infrastructures, making friends and much more.

        And those oldtimers that maybe used to be pioneers.. They got grumpy and refuse to do any homebrew anymore. Instead, they buy expensive equipment to feel great and superior.

        Also, they usually make fun of their younger self and tell you how they used to be young and unexerienced, too, when they built their own stuff – thus essentially devaluing other young hams’ attempts to homebrew.

        And no, I’m not making things up. That’s what I often notice when listening to my home town local VHF repeater or reading the group conversations on Whatsapp, Telegram etc.
        Of course, there must be exceptions to this, as well. I’m hopefully not the last DIY person in my place.

    3. Or combine both! Tubes are excellent as a RF front-end to receivers!

      Tubes don’t overload as easily as transistors and they don’t die due to high static!
      Makes them perfect for long wire antennas that may get also charged up in the wind.
      And if they overload due to a signal too strong, they do go softly into saturation.

      Transistors don’t do that. They get blocked and become deaf.
      Also, field-effect transistors,- those wanbabe tubes -, are extremely sensitive and die like flies.

      However, combing both is a win-win scenario.
      Even impedance-wise they can support each others.

      I’m not kidding! Tubes are excellent for RF stages and preamplifiers, not just fat linears (PAs).
      (Too bad Nuvistors never really made it!)
      Just use a tube/valve for that respectively and let the transistors do the mixing.

      In fact, about ten years ago, I’ve built my own digital radio receiver (DRM) with DREAM software, an EF95 battery tube and a 4 MHz crystal with a helping capacitor to receive RTL radio at 3995 KHz.

      The schematics I’ve used were from these sites:



  12. I am a very happy owner of Belka-DX: it’s a very small radio (similar to a cigarette package) but very powerful. It has SSB, filters and IQ output.
    I am just waiting to receive a SMA-30 antenna to improve my reception.

  13. May I speculate that in places where government, or rather illegitimate thugs posing as a government, have declared listening to shortwave radio subversive then radio receivers wth any kind of significantly powered local oscillator may be risky, they can generate radio noise which may sometimes be detectable at close range. I would suspect SDR is fully safe against this, and a lot of modern low powered oscillators probably only run this risk when the KGB thugs are already within your house and can see the radio set, but definitely local oscillator emissions were how the gestapo in WW2 and the stasi in parts of the cold war tracked down radio listeners in some circumstances. They definitely had enough power that spies sitting outside an embassy could tell which frequencies the embassy listened to, and hence work out what frequency the embassy’s covert personnel within the host country used when they wanted to report things to base.

    1. Yours is the first post anywhere that I’ve seen which points out the problems with local oscillators and security of the listener. Long after WW2, the Brits would detect unlicensed TV receivers by using mobile vans with sensitive VHF receivers and directional antennas. They were looking for the LO. In the USA, there was a TV ratings company that attempted to collect viewing habits by using the same concept. This was in the days of no cable, no internet TV, and only 12 VHF channels. Going back in time a bit, I was working on a BC-611 USA walkie talkie, the kind used during WW2. Single conversion HF rig around 3-6 MHz. I had the spec analyzer up and powered on the rig. The LO leakage was within 13 dB of the XMTR’s output. The enemy could have DF’ed these devices quite easily. To the current time, I think that an SDR disguised as a USB memory stick would be the ideal clandestine receiver (assuming that possession of a laptop and 2 meters of fine wire for an antenna is not treason).

  14. The biggest problem with shortwave listening today is the proliferation of devices producing multiple interfering signals, such as computers, routers, smart meters and consumer electronics designed with little or no shielding. Most days, I find the entire shortwave spectrum is unusable due to noise.

    1. AGREED -although it depends where you live of course ! Some very rural coastal areas (such as NZ’s South Island where I was raised) offer astounding SW (Short Wave) reception -I was further blessed with land enough to string huge antenna.

  15. Before there was any knowledge on my part of what was to come between Russia and Ukraine, I was eyeing a couple of models of SWR’s both in the 30~40 Watt range with 9 bands and SSB. I’m kicking myself for not moving ahead on any of them back then. None of the stuff I was looking at then is available now. Looks like I’m going to be stuck with some other designs of lesser power but hoping I can get a working 8 band SSB SDR system working soon.

  16. The used markets are filled with HF receivers and amateur radio gear. There are 750,000 amateur radio operators in the US alone, and the HF bands are as busy as ever. So… subversive? I think not. But kudos for inspiring home builders.

  17. I have a Shortwave radio. It is an antique ( year 1938) and still works in both SW and AM. I listen various radio station on, like for example Radio Havana Cuba. It’s fantastic!

      1. Jenny List: So you missed all the fun ;-)

        In the 70’s the AM bands were a seething jungle with thousands of radio stations, but also many “weird” radio services of all kinds imaginable. Since ca. 1990-2000 it’s just a desert by comparison, with a few dried plants here and there.

        How did Peter Gabriel sing so beautifully in “here comes the flood”, back in the 70ies:

        When the night shows
        The signals grow on radios
        All the strange things
        They come and go, as early warnings

  18. It isn’t optimal, but many discrete AM radio circuits are easily retuned to portions of the short wave broadcast bands by simply tweaking ferrite core inductors in the local oscillator circuit with a screwdriver. If there are front end filters, further tweaking may improve reception, and IF filters can even be retuned sometimes, for more appropriate IF bandwidth performance. It all depends on the receiver, but such simple retuning will often do the trick!

  19. I’ve been fascinated with Shortwave Radio for many years now, but it’s just tough to get any kind of signal nowadays due to so much noise where I live. I usually tend to listen by way of internet controlled SDRs these days, it’s not the same as listening on an actual radio, but there’s still a charm about it.

  20. The direct sampling mod doesn’t need to be performed on the RTL-SDR v3 which is the version of official RTL-SDR dongle you can buy today unless you’re unfortunate enough to get a clone or an old version of RTL-SDR. The RTL-SDR is a decent starter, but there are far better SDRs available on the market like the SDRPlay RSP1A.

    You would probably be just as happy if not more with a Tecsun PL-330 as you would be with an RTL-SDR.

    A Tecsun PL-330 and an MLA-30+ is a good setup, the only issue you will have to contend with is local QRM/RFI/interference that will kill your ability to receive a listenable shortwave broadcast.

  21. This takes me back as well. In the 60’s out on the farm there was little to do after dark at times so I worked SW. Started with a no name tube radio then a Heathkit HR10b and then a Hallicrafters. I sent to tapes to every station I heard and received QSLs from each of them (I still have them). Radio Tahiti even recorded music on my tape and sent it back. I even scored 2 special ’73 stamps issued by Radio Netherlands. My parents even had to explain to our small town post office why I was getting a quarterly magazine from Radio China. The late 60’s was not a good time to receive mail from China 😁. Now that I live out in the country again I have started looking for a good set. I miss Whites Radio Log, Radio-TV Experimenter Magazine, and listening for Interval Signals.

  22. We had a consoe radio when I was a kid, I think a 1936 Philco.
    The times I had with that thing. I agree there is alot of noise today that
    we didn’t have back in the 60’s and 70’s.
    Also consider not every part of the world has access to the internet,
    and TV/radio/shortwave is the only way to get news unless you wanted to
    wait a day for the newspaper (if any).
    You have to go to a rural area with few humans and practically no manmade
    noise. Still though, when I do find myself out in a rural area, I have
    a small radio with me, and the magic of my youth is still there.

  23. Nonsense, With today’s polluted EMI from switching power supplyes, from computers, lamps, home appliance, it’s almost impossible to get a decent reception.
    I still own a 60’s vintage short wave radio and several am receivers, and it’s impossible to catch long distance radios. May be from time to time some very high power chienese station can be heard.
    On father’s day 2019, a blackout left Argentina without power supply for almost a day, squelching all the interferences, at this moment I was able to hear Am stations 500 even 1000 kms away.
    Toway would be impossible to set a 3 tube spy radio as was used in the 1940’s.
    The solution now is VPN’s to enable users to jump over restrictions.
    BTW this would be useful for european users, that want to hear the Russian version, since all their media is censored in western europe

    1. And a lot of that EMI can cause other problems. We were troubleshooting some issues with our old ADSL connection with two of the local techs from our provider. When looking at the bit loading spectrum we could see some dips and they mentioned cheap Chinese plug packs, even in other houses in the street could be causing it.
      Sadly, here in Australia, the ABC stopped their SW broadcasts. There were some isolated communities that relied on those broadcasts due to the coverage that SW could give. It was the only thing that could reach them and outback truckers.
      Funny story, Mum and Dad were in Papua New Guinea in 83-84. Where they were in Kavieng, they used to be able to listen to Radio Moscow (the station, not the group) on their Sony ICF-2001. They only had the standard telescopic antenna too. I remember listening to Radio Port Moresby about 10 years later while on holiday in Bega, N.S.W. on the same radio. Brilliant bit of kit it is.

    2. Unfortunately what you experience is pretty much global in urban areas of today. A phasing network is a feasible bandage eg. MFJ-1026, not cheap and somewhat fiddly to use. It is worth a try if one can afford it, or alternatively one could homebrew one.

  24. Another option for a simple shortwave receiver is the regenerative receiver. Simple designs consist of a single FET like an MPF102 and either high impedance crystal earphones or a simple single chip audio amplifier and a transformer to go from 1k to 8 ohm. Designs are easily found on the web.
    One factor that could work against a covert radio listener is the regenerative design is an oscillator and puts out a signal. During WWII, there were direction finding vans that would drive around an occupied city and find listeners through the signal given off by their regenerative receiver.

  25. I used to listen to radio Australia about 20-30 years ago, I just to listen again for the last couple months, it really disappointed that radio Australia has stop broadcast. I hope they come back one day, as they has such a great multi languages service. Aside to that I listen to many countries around the world and enjoy collecting shortwave radios ;)

    1. One sunny summer afternoon back in 2013 I heard a station on 25m band, where people talked English with a familiar accent loud & clear. After listening for a while, they announed that they’re ABC Radio Australia, and then I realized I’ve been listening a station on the other side of the Earth. They probably do Internet streams, but catching them on the “real” radio was much more interesting.

      1. Yes they do but the local radio is not as comparable to the shortwave, the show the music, the culture, the feeling it just awesome to listen on shortwave radio on internet. When I hear the music brought me back all the memories
        Here is the video they shutdown, but the station still there.

  26. I was an SWL for 35 years or so (reception reports, QSL cards and all that). BBC’s announcement in 2002 that they were ending English broadcasts to North America was a shock, the mortal blow. We tried to shrug if off. I got a deal on a new Drake R8B (1/2 price) later that year, but I guess they knew the end was nearer than I. More and more the international broadcasters left the airwaves.
    Weren’t the radios manufactured proof of the audience? Higher-quality communications receivers weren’t made for people who were not listening. I’m not one for podcasts, getting a transmission “from over there” was part of the fun. (I would not have called an 800-number to listen to programs on the telephone.)
    It was all very educational and I miss it a lot.

    1. I’m still listening nowadays even though some have left but there are still quite a a number of stations, especially CRI/CGTN, radio Kuwait, BBC, NHK etc..
      It’s kind of blessed in a way where I can now owned many old shortwave in a cheaper price (my collection) otherwise I would not opportunity to own all Sony shortwave portable radio.

  27. When I was a lad I started with an 1154/115 tx/Rx set out of a WW2 Lancaster bomber. I built several valved sets, then started using transistors and moved on to building mobile 25w set going out on 144mhz SSB

  28. A number of years ago this brief unsigned comment appeared on a Wikipedia talk page:

    ‘We here build regenerative radios ;)) There are two circuits for FET and BJT respectively, we call it “three-pointie” (“трёхточка”, “trehtochka” in Russian) – almost nothing is needed beyond a throttling pot, transistor, LC and 1,5V cell.’

    Unfortunately I’ve never found an authoritative description.

    Two things are definite. First, anybody who believes that just because we can easily buy chips etc. to build an FM or digital receiver in the developed/Western World they’re equally available everywhere, and uses that as an excuse to shut down high-powered AM transmission, is an utter fool. And anybody who believes that it’s safe to expect subjects of a totalitarian regime to use the Internet to connect to the Free World’s news services- directly or over any sort of tunnel- is unutterable.

  29. Regarding propaganda/misinformation/disinformation per se: In the 1980’s through the 1990’s I was fascinated with shortwave radio. I was so taken with international communications I eventually became a paid reception reporter for the BBC World Service. In fact, when Mikhail Gorbachev was deposed in a coup d’etat it was through BBC Russian Service radio that he knew what was happening as the USSR deteriorated. The USSR was so secretive in those days they literally had a network of 100 transmitters around its enormous border specifically for jamming the frequencies of BBC, VOA, AFRTS, Radio Free Europe etcetera. As reception monitors we often heard and reported when the jamming was ongoing and which frequencies were impacted.

    The successful propagation of shortwave radio is heavily impacted by solar activity and the various layers of the ionosphere. The layers of ionosphere is used to bounce the signals off of for targeting. The radio waves literally bounce off of the ionosphere down to a continent and then skip up again and on and on. A term for hearing a signal twice is called back-scatter, and this means the conditions for propagation were so good the signal was circumventing the earth twice almost simultaneously. Radio transmissions are expensive and require much energy to generate. Aside from politics, the reception reports assisted the stations’ with determining quality control and discerning the most favorable conditions for ideal, efficient and economical targeting. The physics undergirding radio propagation is no less fascinating than TCP/IP protocol.
    This protocol is known as packet-switching and similar to radio waves transpires at very nearly the speed of light.

    In a real sense, Radio this was the precursor to the WWW. One of the first moves against its citizenry by the Nazi Party was to confiscate all radios capable of receiving any communications from neighboring countries. The Nazi’s subsequently issued radios with only the capability to receive approved frequencies.

    As an aside, the people of Japan had never heard the voice of their Emperor Hirohito until the day he officially surrendered. Emperor Hirohito was considered by the Japanese to be a living God. The authoritarian effort to control the free-flow of information continues to this day, only in a new form.

    I specifically specialized in monitoring Communist countries or the Soviet Block, also known as “behind the Iron Curtain ” principally the USSR in regard to espionage and propaganda. I communicated with Radio Kiev, Radio Prague, Vilnius, Berlin, Sofia and Moscow of course, and many others. I worked for newspapers in those days and collected articles that were neutral, or favorable to those nations without being bombastic or denigrating. When I sent reception reports (called QSL’s) to these countries I included the clippings to get past the official government censors. This was somewhat risky because the USA considered these nations to be “sponsors of international terriorism” and citizens were forbidden to communicate with them. Since I was using the US Mail, I knew the authorities opened and read my letters. Because it was a form of quiet diplomacy (as opposed to espionage) it was tacitly allowed, or tolerated. Nevertheless, Russian and China government suppression and censorship prevails in this new cyber medium.

    1. “The Nazi’s subsequently issued radios with only the capability to receive approved frequencies.”

      “Nevertheless, Russian and China government suppression and censorship prevails in this new cyber medium.”

      Meanwhile in the “Free Western nations”, RT and all Russian media has effectively been banned and there are more calls for deporting and/or not allowing Russians into the US or other European Countries. Social media and tech companies censor any objective reporting as “Russian dis-info” and any opinon that doesnt align with open borders, anti-racism, and pro-lgbtp. Has the thought ever occurred to you that maybe “Democracy” is a lie and US hegemony is evil rather then good? Why does the USA think it is so important to force gay/trans rights on countries and force them to take in 3rd world migrants?

    1. In Canada,
      If you had your marine radio permit in the service, than transitioning to a basic amateur license is usually just filling in a form with your ID..
      If you want to handle over 250W or use HF, than you will need to write for your advanced license.
      If you want to volunteer as an instructor, than you will need to have the Morse certification as well.

  30. 3-30 MHz SW band noise, be it atmospheric/solar or man made, can call for noise blanking circuitry -or a move to a quieter reception region ! However at lower freqs (perhaps MW) weak signal reception can be wonderfully enhanced with an inductively coupled resonant loop antenna. Check my popular 2009 era Instructable for a DIY version => https://www.instructables.com/Medium-Wave-AM-broadcast-band-resonant-loop-antenn/
    Stan. (ZL2APS since 1967)

    1. There are fewer not more Number Stations, although they are easy to find with the tools available.
      There are fewer Broadcasters also. I was a Deutsche Welle Technical Monitor. DW is a shadow of its former self
      Just got a Tescun Pl-330 great little radio that won’t break the bank $79.00 Amazon.

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