That's such a pity. Building a simple AM radio receiver was a simplest and coolest electronics project to do with kids.
You need two transistors, a ferrite coil and a small set of simpler elements. And it is so simple you can actually explain what every part of the circuit does.
And then the reward... Once built you could listen to BBC regardless of where you are in Europe. My kids just LOVED IT, no Netflix K-Drama replaces this experience. My daughter was listening to BBC on her radio every night going to sleep.
Yes, I did exactly this in England 30 or so years ago. It was one of the suggestions in an electronics kit for children, the one with springs to connect the components together.
> The process by which a Trident submarine commander would determine if the British government continues to function includes, among other checks, establishing whether BBC Radio 4 continues broadcasting [on long wave]
> Submarines on patrol were reported to have briefly gone on nuclear alert in 2004 when Radio 4 went off the air for 15 minutes due to a power cut.
I was listening to DAB in the car, not so far from here last weekend, and it kept cutting out. Whereas you could get LW everywhere!
I developed a love of cricket on Test Match Special from a very young age. A tiny inexpensive radio could get it anywhere. I actually never minded the interruptions from the Shipping Forecast, the real reason they kept this service up for so long. I know there are many ways to get a forecast now, none of which is as reliable as radio 4.
In the HBO miniseries Generation Kill the marines are tuned into the beeb long wave to get news updates, and there's a cricket score read out in the first episode
Some things in life happen for the very last time and we never realize it. Where were you when Jim Maxwell interrupted the test match coverage, for the final time, to declare that “listeners on long wave will now hear the shipp-ing four-cairst”? :)
Digital radio was always going to be crap, it doesn't degrade gradually as signal gets worse
They should have just put all the money into a better 4G network and ran radio through that.
> it doesn't degrade gradually as signal gets worse
That has a lot more to do with the dated implementation and less to do with digital radio. There are a number of digital broadcasting techniques which can minimize and compensate for noise, including a slight delay with a signal correction and fault tolerant codecs.
DAB was implemented using the old MPEG2 audio codec. DAB+ uses the now 15 year old codec HE-AAC which isn't really designed to handle corruption. Opus handles loss a lot better (see their examples https://opus-codec.org/examples/ )
Bit of hindsight bias there, DAB was first developed in the mid 1990s, ubiquitous fast wireless IP in everyone’s pockets is at least a decade, perhaps nearer to 20 years in the future. There are quite a few transitionary technologies that we needn’t have developed had we just waited for something better to come along (but without the R&D into some of them…).
(Also doesn’t analogue FM also kinda cut off fairly abruptly?)
FM stays listenable even with heavy distortions when you drive out of range and you can decide for yourself when you no longer tolerate the signal. Digital doesn’t give you warnings and just goes silent
Some more than others. E.g. Deutschlandfunk Kultur is broadcasted in decent quality, as is NDR3. Klassik Radio fares poorer, but that's due to the bandwidth allocated to them.
Especially so with digital public TV. its absolutely unusable. and now they can't stand that people want to share sports broadcasts, so they are updating it again to add encryption. I can't believe anyone watches it.
One-to-one communications and broadcast communications are different. Perhaps every 4G tower could broadcast the news on a special data channel, but it would be a separate system from the main 4G data channel.
IMO, when the last LW transmitter shuts down, the whole band needs to be reallocated to hams. Realistic small-ish antennas are shockingly doable with a capacitance hat, loading coil, and counterpoise.
There’s still a lot of utility stations in the LF/longwave band. Particularly time signals (WWVB in the US, ALS162 in France, DCF77 in Germany, JJY in Japan, etc.) and NDB beacons.
At least in VK/Australia, there’s the 2200 meter band, but it’s quite limited (1W power limit, CW/digital only, 135.7–137.8 kHz).
At the same time, as much as I don’t want the AM broadcast band to die, I’d love an amateur band in the lower/middle part of MF/MW.
> There’s still a lot of utility stations in the LF/longwave band. Particularly time signals (WWVB in the US, ALS162 in France, DCF77 in Germany, JJY in Japan, etc.)
I meant just the broadcast band 148.5-283.5 kHz. (Though I'd love if 2200m and 630m were just a bit wider.)
> and NDB beacons.
Good point[1]. So 148.5-200 kHz in ITU Region 2 (and keep LowFER allowances on 160-190kHz as a consolation prize.)
In the UK we have 2200m but it's 1W *ERP*, so you're probably running a good couple of kW to get there with any practicable aerial.
We've also got a chunk just off the bottom of MW around 475kHz, which ought to be good for long-range night-time communications. It's licenced for CW, QRSS, and narrow-band digital modes.
There is a very small slice that amateur radio gets in this band, in theory it would be nice to have a bigger slice, but honestly, building antennas for this band to transmit anything worthwhile would be pretty hard.
My 7 Mhz antenna (HF, 40m band) is 67 feet long, and goes across by whole house.
The smallest antenna you could get away with for LF would be hundreds to thousands of feet long.
You might be able to go smaller if you enjoy suffering. Though, there are some pretty creative antenna designs that defy logic.
The witness of the conspiracy practice in me says that the opposite is more likely to happen in the world whose govenments strive to limit its ineterconnectedness and turn it into a set of isolated anclaves not unlike Orwell's Eurasia, Eastasia and Oceania.
The next logical step in that direction would be cracking down on HAM, not liberalization of it.
With the risks to GPS becoming more acute, many jurisdictions are seriously entertaining bringing back a modern version of LORAN.
There's also high frequency firms that want to muscle their way into shortwave frequencies as they can have lower latency between trading sites (eg NYC and Chicago) since the physical infra isn't a direct link as the crow flies (as well as the speed of light being slowed in fiber optic lines). They've even restarted some microwave links, as they don't necessarily need a lot of bandwidth, just latency.
I hope not. I am saving $80 per month by recording over-the-air TV using Tivo. I only want the major networks, and recording them over the air is free. Tivo DVR is great for OTA and their service is still active but sadly they have stopped selling their DVR.
These transmitters consume insane amounts of power. Per Wikipedia, that's 500 kW of rated transmission power for this one [1], so probably a solid megawatt of grid power input.
At 30 ct/kWh, that's 300€ per hour, 7200€ per day and about 2.6 million € a year - for a customer base that is only decreasing.
And by the virtue of shortwave propagation, it could be heard across the world. For the past month and a half (from when the news of its impending shutdown was revealed) I was regularly picking it up in Australia right up until the bitter end.
HF propagates through skywave (most reliably from 5-30MHz), which is where the signal bounces off the ionosphere.
In the MF (AM broadcast) band, you can observe this at night - in Australia I can pick up the 50kW Melbourne ABC station (public broadcaster) at 774kHz with a good radio, just about across the entire country.
In the LF (longwave) band, the earth’s surface and the ionosphere start to behave more like a waveguide than skywave. This is actually more reliable/consistent than even HF, but you need massive transmitting antennas due to the large wavelengths involved.
HF also generally wins for distance covered per watt - despite the massive power of Radio 4 longwave, I’d have no chance of hearing it reach Australia.
Also bear in mind that Droitwitch is radiating 3 different services. Talk Sport (1053 kHz), Radio 4 (198 kHz) and Radio Five Live (693 kHz).
My suspicion is that this means an exciter and a stack of amps per service, which then go through a two stage combiner and out to the antenna. There might even be a pair of exciters and amps per service depending on redundancy.
The combiners (certainly for FM/DAB/TV services) also cause cumulative attenuation as the signal gets combined each time, so even if all 3 are radiating at the same power, the first in the chain might need twice as much amplification to make up for losses.
As far as I know the medium wave services aren’t transmitted from the same antenna as Radio 4 LW, they have separate antenna, albeit with one of them (5 Live) doubling up as one of the support towers for the large long wave T antenna slung between the two large towers on site. Although I suspect the plan would be to move 5 Live to the currently unused Absolute / Virgin antenna eventually so they can demolish the long wave setup.
You're absolutely right and I was flagrantly wrong - Droitwich does use different antennas for the different LW and MF services (though still has to combine the output of two transmitters for the same service to increase the power and offer redundancy).
I was very much getting myself confused with some of their other transmission sites where they take multiple DAB or DTV services, modulate, amplify and combine them and then broadcast through the same antenna.
I can't edit my previous comment (which incorrectly implied that the 3 stations at Droitwitch are going out of the same antenna), but I've done more research and have more information.
Droitwitch LW's antenna uses a T-aerial suspended between two 210m steel masts acting as massive capacitive top-loaded vertical monopole. The signal isn't beamed or shaped, it propagates omnidirectionally and this style of antenna offers _0 dB_ of ERP increase.
Even worse, they're transmitting AM, so the power output dynamically increases with the volume of the analogue audio being transmitted. If you cut off the input to Droitwitch, it'd still be putting out a 500kW carrier wave. When audio is applied the amplitude of the carrier is modulated, so for peak loudness (someone shouting or the loudest spike in music) it can take an extra 50% power to create the upper and lower sidebands - at peak, the Vapotron tubes could be putting out a combined 750kW.
The amplification stage is only ~70% efficient as well, so at peak power it's possible that the site is pulling nearly 1MW from the grid.
--
Compared to a modern UHF DTV transmitter station the differences are wild. The big transmitter near me is putting out 6* DTV MUX's at 174kW ERP each, but that's through a 15dBd UHF array at the top of the mast which gives an obscene amount of gain.
- Mains draw at the wall ~150kW (including cooling and ancillary systems).
- Total TPO (RF energy leaving the cabs) from each of the six transmitters is only ~52kW combined (8.7kW each)
- Output of the combiners after losses of ~0.5dB is ~46kW. We can expect another ~1.5dB of attenuation after forcing it up 300m of waveguide to the top of the tower so we're now sat at a "mere" ~33kW of RF energy going into the bottom of our antenna.
- 33kW with a +15dBd gain gets us to an ERP from the antenna of 1.044 MW.
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Note: Numbers compiled from public sources. All mistakes and misunderstandings are mine. Whilst I do work in a tangentially related industry this is completely out of my area of expertise - in the same way that working as a cleaner at an aeroplane does not mean one knows how to fly or maintain a plane.
I'm sad to hear the service has gone off the air. I was a constant listener to BBC Radio 4 on 198 kHz growing up in Dublin. It was a valuable window onto the world.
Listening to the last transmission there, I note that the continuity announcer, (the Irish) Al Ryan, signed off with 'oíche mhaith', i.e. 'goodnight' in Irish. A nice nod, I think, to all the former LW listeners in Ireland.
One can listen to the live closure broadcast via this WebSDR website, by tuning it to AM 198 kHz.
"You are listening to 198 kHz longwave. BBC Radio 4 is no longer available on this frequency. However, you can find Radio 4 many other ways. You can find BBC Radio 4 online, via BBC Sounds. Radio 4 is available on DAB digital radio and through your digital television, including freely. Radio 4 is also available via FM radio, on 92 to 95 MHz and 103 to 105 MHz. Plus, you can listen via your smart speaker: just say 'play Radio 4'. Information on how to listen can be found on the BBC website, at bbc.co.uk/reception."
The Droitwich transmitter used to transmit on exactly 200 kHz which I always thought was very cool, but it moved to 198 kHz in 1988 to better harmonize with European stations.
The program was mostly the same as BBC Radio 4 but it used to diverge at certain times of day. I used to be woken up at 5am every day by my parents clock radio with the farming news which was very dull, but easy to sleep through.
"Longwave", usually written without a space, is an informal and not well-defined term for radio frequencies lower than the AM broadcast band, which in Europe is known as "medium wave".
In the USA there have never been commercial longwave stations, though various WWV time signals are broadcast in that band.
"Although the transmitter was in Ireland, the signal's reach meant that it was often looked upon as a "UK national station". Reception reports were received from such locations as Berlin, Finland, Ibiza and Moscow."
That's a real shame given the distance LW could travel: I wonder what they're going to use the frequency band for? I've tried using DAB on so many occasions and thrown it out in disgust.
> Given these factors, investing in upgrading the LW equipment is not considered a cost-effective solution for licence fee-funded services
And that's another problem - maybe the Government should step in and set up a proper Civil Defence-style warning/information system - we may well need it in a few years - it's a shame our official National Broadcaster can't fulfill the role.
Side Note -
VLF ( Very Low Frequency ) signals (3-30 kHz) propagate via surface wave or skywave, offering stable communication for submarines through saltwater.
That is too bad, you would think these could be kept active for historical purposes. But seems these services are all being turned off even though I heard a few were very useful in this day and age.
This transmitter doesn't really have the range for reliable global communication, it's optimised for covering the UK. For the global communication usecase, there are other networks of military transmitters (DHFCS) that are much better suited for the job, and they aren't being shut down any time soon.
What it did provide was a simple but reliable way to maintain emergency broadcast to general public within Britain. And it probably should have been kept online just for that reason.
Except nobody has a radio any more, certainly not one that receives LF. People have cellphones, and cellphones have a mandatory feature that lets the government display a message on everyone's screen, usually accompanied by loud and scary beeping. That's the new emergency broadcast mechanism. It's not as simple, but at least people actually see it.
I got my RTL-SDR to see what I could listen to, and by the time I tuned in, nearly all the short wave stations I could tune to were just broadcasting evangelical religious stuff, or other crazy conspiracy stuff. It's remarkable that these powerful stations spend most of their broadcast day transmitting that content.
It's like the moon rocket. At any time we could have restarted that program from scratch and run it again, but what would the point be? We don't have the direct ability to make one but we have the ability to gain the ability to make one.
If we did regain the capability it would probably be solid-state.
I don't think it's like that at all. I bet you could build a perfectly serviceable replacement at home without needing to spin up any special manufacturing equipment, using off-the-shelf components.
For that matter I'd be somewhat surprised if you can't simply buy a ready-made replacement.
We do spend out quite a lot here in the UK for the BBC. They could easily dump a couple of expensive presenters and use the savings for vacuum tubes, if that is what is needed.
No idea where vacuum tubes were invented but I'm sure the BBC could find someone to make them.
> No idea where vacuum tubes were invented but I'm sure the BBC could find someone to make them.
The BBC has just cut its budget by £500 million, in an apparent attempt to limit the damage from the latest charter renewal process - which determines its funding. The new director general (ie ceo) is an ex-Google person, and they seem to be pivoting to become a social media content provider. So I'm pretty sure that spending licence fee money on making vacuum tubes to broadcast a signal that nobody under forty listens to wouldnt get past a value for money test.
(I like the BBC and its radio output, and I'm one of those weirdos who still pays the licence fee despite never watching tv or any of the stuff that the licence fee is required for. But it is becoming increasingly lost to me: focussed on triviality and politically cowed. Sadly, I no longer expect it to last.)
I thought the license fee was a tax. You have to pay it, except in extremely specific scenarios that are basically just the bureaucracy's way of saying it's technically optional even though it isn't. AFAIK you have to own no devices capable of receiving BBC broadcasts - this includes most phones and computers since they broadcast on the internet.
I'm sure they could, but sourcing people willing to manufacture heavily equipment/processing intensive speciality products for tiny runs will be MINDBLOWINGLY expensive.
This isn't about the little tubes that go in a guitar amp... we're talking about tubes that may well be too large for a single person to lift.
What's more, everyone who knew how to build things is either dead or in a retirement home. You'd have to re-engineer much of it from scratch.
Exactly - and look what those cost despite being produced in relative quantity. Now scale up to something that's 1000 times the size with 1/1000th the production volume. Wouldn't surprise me if the per-tube cost was in the millions.
Nixies are also cold cathode, low current devices. Radio broadcast tubes can be handling tens or even hundreds of thousands of watts.
Why do you think bots don't control the mass media, of which longwave is just one outlet? Go to the website of any outlet that has longwave, read the AI nonsense there, realize they're transmitting the same on longwave.
Listened to this in Denmark in the car just yesterday. It usually sounded awful but was the only English language news source in the car, so I’m going to miss it. Since the BBC sold the transmitters and rented them back, let’s hope we don’t get US-style right wing talk radio as a replacement.
At the moment they are running a goodbye loop, so you can still hear something.
At least there’s Radio Caroline still on 648kHz AM, so there will be a British voice still on the air.