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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

#161

Post by [deleted] »

eichin wrote: post #148
WarOnPrivacy wrote: post #136

Droitwich uses two metre-high ceramic and metal valves, which are no longer made. said valves: https://www.radiorewind.co.uk/images/1983027.jpg https://www.radiorewind.co.uk/images/1983023.jpg from: https://www.radiorewind.co.uk/radio1/droitwich.htm https://i0.wp.com/www.richardmudhar.com/blog/wp-content/uplo...

"valves" being british for vacuum tubes (though there's an entire generation of scifi where future computers are built around miniaturized valves even among american authors for some reason, Asimov in particular)

[deleted]

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

#162

Post by microgpt »

aeonik wrote: post #120
microgpt wrote: post #89

Earlier quoted context omitted.

Does stapling it to your neighbours' fence lines and painting it like the wood count as creative? I wonder if you can couple to your local distribution grid, and not get arrested.

I just string the antenna across my attic. Coupling into my power upstairs is a bit of a problem sometimes though. Pirating power is something I've heard that happens, but I looked it up, and couldn't find an actual cited example of someone doing it via induction. Plenty of people doing it via extension cords and device tampering though.

I meant feeding RF back into the power grid to use it as your very large antenna

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

#163

Post by microgpt »

myotheraccount2 wrote: post #113
aeonik wrote: post #73

Earlier quoted context omitted.

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 s…

Here you go. https://theradiosource.com/products/antenna-630pd.htm

I understand that while you can add substantial capacitance and inductance to make an "electrically long" short antenna for a long wavelength, its effectiveness at transmitting and receiving is still proportional to its size - the signal will be pretty weak?

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

#164

Post by Marsymars »

Peanuts99 wrote: post #37
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…

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.

I guess depends on your definition of "crap". In practice, my city has some hills, and none of the half-dozen FM stations I listen to in my car come in without static in some places in the city. Whereas the single HD Radio station has perfect reception, all the time. Plus the sound quality is noticeably better.

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

#165

Post by Marsymars »

mschuster91 wrote: post #6
_whiteCaps_ wrote: post #3

Seems like everyone's shutting down radio services. CHU and Weather radio in Canada too :(

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. [1] https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station

The parent comment was partially about Canada's VHF Weatheradio service - that was comparatively much lower power - the average station power was somewhere around 200 watts ERP.

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

#166

Post by microgpt »

microgpt wrote: post #163
myotheraccount2 wrote: post #113

Earlier quoted context omitted.

Here you go. https://theradiosource.com/products/antenna-630pd.htm

I understand that while you can add substantial capacitance and inductance to make an "electrically long" short antenna for a long wavelength, its effectiveness at transmitting and receiving is still proportional to its size - the signal will be pretty weak?

Then I remembered the way these electrically short antennas work is by resonating the signal within themselves so you're basically transmitting a really high amount of power with a really low efficiency (and the rest stays confined between the antenna and its extra L/C loads until it gets transmitted).

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

#167

Post by jcsager »

alentred wrote: post #41

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 r…

My dad helped me build a crystal set when I was about 7. I still remember listening to a serialisation of Lorna Doone on the (MW) Home Service on headphones under the bedclothes.

Sad that the LW sevice had to close but the BBC is short of cash and it won't get better either.

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

#168

Post by WarOnPrivacy »

gorgoiler wrote: post #154
WarOnPrivacy wrote: post #150

Earlier quoted context omitted.

> when Jim Maxwell interrupted the test match coverage for the final time... Jim Maxwell has thrown to the shipping forecast for the last time -- July 31, 2023 ref: https://xcancel.com/abcsport/status/1685999353712848896

You absolute bloody gem. Brilliant. Thank you :)

I asked Kagi's Assistant. It's been surprisingly helpful.

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

#169

Post by [deleted] »

K0balt wrote: post #84
toxik wrote: post #40

Earlier quoted context omitted.

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.

What are they wanting to build? It’s hard to put much information on lower frequencies, afaik?

[deleted]

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

#170

Post by aeonik »

microgpt wrote: post #162
aeonik wrote: post #120

Earlier quoted context omitted.

I just string the antenna across my attic. Coupling into my power upstairs is a bit of a problem sometimes though. Pirating power is something I've heard that happens, but I looked it up, and couldn't find an actual cited example of someone doing it via induction. Plenty of people doing it via extension cords and device tampering though.

I meant feeding RF back into the power grid to use it as your very large antenna

You nerd sniped with this one.

I looked it up, and apparently utility companies already use the lines for comms, so you would be stomping on those potentially (depending on frequency).

As for radiating... Possibly... But the tuning seems ridiculously hard/out of your control.

The conductors are huge, and I can't imagine getting a stable RF standing wave across grid scale infra like that.

I'm sure it's possible... Those lines are actually too long and changing electrical length for most useful RF.

I'm going to have to dig a bit deeper though.

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