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.
raverbashing 56 minutes ago [-]
Look at this fancy pants needing a transistor for that /s
(but yes I do miss those simpler days - but I guess the basics now is making an Arduino flash an LED)
jimnotgym 5 hours ago [-]
I'm very sad to see this go.
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.
gorgoiler 3 hours ago [-]
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”? :)
With apologies to Affabeck Lauder
Peanuts99 4 hours ago [-]
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.
microgpt 17 minutes ago [-]
One-to-one communications and broadcast communications are different. Perhaps every 4G tower could broadcast the news on a special data channel, but you don't get it for free.
fredoralive 2 hours ago [-]
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?)
mybrowsercache 30 minutes ago [-]
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
guenthert 5 minutes ago [-]
Your receiver can (and many do) display signal quality. Not playing distorted, noisy signals is a feature I greatly appreciate.
expedition32 60 minutes ago [-]
I have a DAB radio and it gets constant interference. Meanwhile FM is stable. In the same set up.
Really soured me on this digital radio technology.
Scoundreller 5 hours ago [-]
A/The real reason was that electricity meters were built around a part of the signal being used to switch between price tiers but recently phased out.
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.
RobotToaster 2 minutes ago [-]
Best we can do is privatisation and selling it to a party donor.
microgpt 16 minutes ago [-]
I thought hams already had plenty of bands. Is there not one in this range?
LeoPanthera 2 hours ago [-]
"Longwave" has no universally agreed defintion, but good news, amateur radio already has usage of 135.7 kHz to 137.8 kHz.
Building equipment that works on frequencies this low, and avoiding natural interference, can be extremely difficult.
yakkers 8 hours ago [-]
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.
bilegeek 7 hours ago [-]
> 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.
toxik 3 hours ago [-]
I hate to rain on your parade, but a lot of interests want the low-frequency spectrum. It will absolutely never be allocated to amateur radio.
goodthenandnow 14 hours ago [-]
That station is said to be one of the signals used by the UK’s nuclear subs to assess the state of the country in a war scenario.
LW is still a fallback when internet and mobile go down simultaneously. Quietly important.
_whiteCaps_ 15 hours ago [-]
Seems like everyone's shutting down radio services. CHU and Weather radio in Canada too :(
mschuster91 14 hours ago [-]
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.
ggm 11 hours ago [-]
Wave skip? (Naieve question)
yakkers 8 hours ago [-]
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.
Is that emitted power, consumed power, or effective radiated power? Without knowing that, your power calculations have no meaning.
Radio stations are usually measured by the last of those: Effective radiated power.
You can have a radio station with a 50,000 watt ERP, but running only a 2,500 watt transmitter.
For FM radio stations, it's all about the height of the transmitter above average terrain. For AM, it's about the ground conductivity and frequency.
I once worked at a 1,000-watt AM station that had a signal much larger and clearer signal than the 5,000-watt AM station a few miles away.
I'm not a radio engineer, but I'm sure there are plenty on HN who can correct and clarify what I've written.
BuildTheRobots 13 hours ago [-]
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.
I believe they're still using a pair of Marconi B6042 transmitters (250kW each, in parallel) to provide at least one of the services.
fredoralive 2 hours ago [-]
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.
BuildTheRobots 4 minutes ago [-]
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.
mschuster91 12 hours ago [-]
> Is that emitted power, consumed power, or effective radiated power?
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.
asdefghyk 3 hours ago [-]
Side Note -
VLF ( Very Low Frequency ) signals (3-30 kHz) propagate via surface wave or skywave, offering stable communication for submarines through saltwater.
ransom1538 29 minutes ago [-]
Why would humans need to communicate on channels bots cannot control?
microgpt 13 minutes ago [-]
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.
nickcw 14 hours ago [-]
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.
mark-r 13 hours ago [-]
Thanks for mentioning the actual frequency. The article says "long wave" many times without specifying what it actually means.
LeoPanthera 13 hours ago [-]
"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.
reaperducer 14 hours ago [-]
It was my father's morning alarm, too. But he was a couple of thousand miles away in New York state.
That, and Atlantic 252 (I believe now long gone) were what he woke up to every morning.
gavinward 13 hours ago [-]
Despite the name I would not have guessed you could pick up Atlantic 252 in the US. The quality of it wasn't great for listening to music.
"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 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.
cjs_ac 13 hours ago [-]
IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.
RachelF 13 hours ago [-]
In some way it is short-sited, as radio is a good backup medium for global communications in case the entire Internet ever goes down.
Vacuum tubes also aren't vulnerable to nuclear weapon electro-magnetic pulses.
However, other than ham radio enthusiasts I guess no one listens to analogue radio anymore.
phire 4 hours ago [-]
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.
microgpt 9 minutes ago [-]
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.
hdgvhicv 3 hours ago [-]
Very few radios can pick up long wave now. My car certainly won’t.
Even when they can most people
Wouldn’t have a clue to listen to it.
There’s a reason LW isn’t critical national infrastructure.
jasonjayr 11 hours ago [-]
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.
pessimizer 10 hours ago [-]
They still broadcast on FM.
dingaling 5 hours ago [-]
... on a patchwork off different frequencies across the UK due to the poor propagation of VHF
fredoralive 2 hours ago [-]
Doesn’t RDS mostly solve that for the most common case where frequency changes becomes an issue (car radios).
gerdesj 11 hours ago [-]
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.
microgpt 8 minutes ago [-]
These aren't just any vacuum tubes. They are each the size of a small fridge, and extremely specialized for use in radio broadcasting.
andyjohnson0 2 hours ago [-]
> 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.)
microgpt 6 minutes ago [-]
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.
TylerE 2 hours ago [-]
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.
microgpt 3 minutes ago [-]
At least you already have some working tubes to start from. Some guy did it with Nixie tubes, of course those are a lot smaller.
jstanley 8 hours ago [-]
It's hard to believe that civilisation has lost the ability to build longwave radio transmitters.
microgpt 4 minutes ago [-]
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.
binaryturtle 14 hours ago [-]
As long we still have DCF77…
downrightmike 11 hours ago [-]
I wonder how many of the Van Allen radiation belts is held up by this
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.
(but yes I do miss those simpler days - but I guess the basics now is making an Arduino flash an LED)
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.
With apologies to Affabeck Lauder
(Also doesn’t analogue FM also kinda cut off fairly abruptly?)
Really soured me on this digital radio technology.
Or
(Links from https://garfnet.org.uk/cms/tables/radio-frequencies/internet... )Building equipment that works on frequencies this low, and avoiding natural interference, can be extremely difficult.
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.
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.)
[1]https://www.dxinfocentre.com/ndb.htm
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.
https://en.wikipedia.org/wiki/Letters_of_last_resort#:~:text...
https://en.wikipedia.org/wiki/List_of_longwave_radio_broadca...
Rather defensive press release thing from the BBC: https://www.bbc.com/mediacentre/articles/2026/radio-4-broadc...
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.
[1] https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station
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.
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.
Bounce off ionosphere
Radio stations are usually measured by the last of those: Effective radiated power.
You can have a radio station with a 50,000 watt ERP, but running only a 2,500 watt transmitter.
For FM radio stations, it's all about the height of the transmitter above average terrain. For AM, it's about the ground conductivity and frequency.
I once worked at a 1,000-watt AM station that had a signal much larger and clearer signal than the 5,000-watt AM station a few miles away.
I'm not a radio engineer, but I'm sure there are plenty on HN who can correct and clarify what I've written.
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.
edit: MB21 (of course) has some fantastic technical info about Droitwitch: https://tx.mb21.co.uk/gallery/gallerypage.php?txid=1454&page... and there's some great pics here, too: https://www.radiorewind.co.uk/radio1/droitwich.htm
I believe they're still using a pair of Marconi B6042 transmitters (250kW each, in parallel) to provide at least one of the services.
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.
Going by [1], emitted power.
[1] https://www.bbceng.info/Operations/transmitter_ops/Reminisce...
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.
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.
In the USA there have never been commercial longwave stations, though various WWV time signals are broadcast in that band.
That, and Atlantic 252 (I believe now long gone) were what he woke up to every morning.
https://en.wikipedia.org/wiki/Atlantic_252
"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."
Vacuum tubes also aren't vulnerable to nuclear weapon electro-magnetic pulses.
However, other than ham radio enthusiasts I guess no one listens to analogue radio anymore.
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.
Even when they can most people Wouldn’t have a clue to listen to it.
There’s a reason LW isn’t critical national infrastructure.
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.)
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.
If we did regain the capability it would probably be solid-state.