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Long Wave radio era set to end with switch-off

economist.com

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Re: Long Wave radio era set to end with switch-off

#41

Post by alentred »

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.

Re: Long Wave radio era set to end with switch-off

#42

Post by gorgoiler »

jimnotgym wrote: post #33

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 ther…

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

Re: Long Wave radio era set to end with switch-off

#43

Post by ErroneousBosh »

yakkers wrote: post #31
bilegeek wrote: post #29

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…

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.

Re: Long Wave radio era set to end with switch-off

#44

Post by hdgvhicv »

RachelF wrote: post #17
cjs_ac wrote: post #14

Earlier quoted context omitted.

IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.

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.

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.

Re: Long Wave radio era set to end with switch-off

#45

Post by andyjohnson0 »

gerdesj wrote: post #20
cjs_ac wrote: post #14

Earlier quoted context omitted.

IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.

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.)

Re: Long Wave radio era set to end with switch-off

#46

Post by LeoPanthera »

bilegeek wrote: post #29

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.

"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.

Re: Long Wave radio era set to end with switch-off

#47

Post by fredoralive »

BuildTheRobots wrote: post #16
reaperducer wrote: post #9

Earlier quoted context omitted.

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…

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) al…

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.

Re: Long Wave radio era set to end with switch-off

#48

Post by jon-wood »

goodthenandnow wrote: post #11

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. https://en.wikipedia.org/wiki/Letters_of_last_resort#:~:text...

Imagine if the end of humanity is caused by everybody assuming somebody else told the captains about this.

Re: Long Wave radio era set to end with switch-off

#49

Post by TylerE »

gerdesj wrote: post #20
cjs_ac wrote: post #14

Earlier quoted context omitted.

IIRC, their operation relies on enormous vacuum tubes that the BBC can’t get replacements for any more.

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.

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.

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