Radio in a pre-industrial world

So I've got this idea for a setting where the level of technology is about on par with 18th century Europe. Lamps still run on whale oil, guns are still in the front-loading musket stage, and the steam engine is only just now starting to take off. However, I want there to be radios. Large, clunky, hand-cranked, extremely expensive radios, but radios nonetheless.

Partly this is because certain plot points I have in mind would work much better if radio communication was a thing. Partly it's to explain why The Empire has been growning at such an exponential rate (it's the first country to develop and make widespread use of radios, giving them a leg up on everyone else). And partly it's just to make the setting a little more unique.

Trouble is, I really don't know enough about radio mechanics to tell whether a society at this tech level could plausibly develop them. I'm sure they could build telegraphs, but y'know those plot points I mentioned above? Some of those would really fall apart if all it took to stop a transmission was cutting a wire.

So, any tech minded tropers who'd like to lend me a hand, how feasible is it to have radio technology in my world?

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

I think a simple spark gap transmitter for wireless telegraphy would be feasible. The question isn't really if it could be built or not at that 'tech-level', the problem is knowing that one can be built. Knowing that there are suchs things as radiowaves, electricity, coils etc.

You need something to power the transmitter with, like a battery, or some sort of generator. Alessandro Volta invented the copper-zinc battery(or "Lemon battery") in 1800, but the battery could actually have been invented much earlier(Baghdad Battery).

Not sure when the first usable(for radio) generator was made but you pretty much only need some magnets and copper coils.

I don't think capacitors is strictly needed but the Leyden jar was invented in 1745, so they would probably be used.

On the receiver end you need some sort of detector or Coherer.

edited 1st Nov '13 5:07:26 AM by m8e

^The Baghdad Battery was the first thing I thought of when I read the OP.

Okay, that's all sounding good. What about transmitting voices over radio waves instead of just telegraphy signals? That's not really necessary for the setting I have in mind, but if plausible I'd like to try it.

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

The first generator was built by Michael Faraday in 1831, so it's probably theoretically possible to have one going a few decades earlier if you move science in the right direction earlier on.

Personaly, I think it's pushing it to far and it would break my Willing Suspensionof Disbelief. A spark gap transmit something that's basically static.

To send voice you need a fairly clean, stable carrier wave and some way to modulate it. Changing the signal strengh in case of AM. This would require greater quality and knowledge about coils and capacitors. I'm not sure but I think it would also need something that work like a transistor, like a triode.

Yeah, a homopolar generator/Faraday disc could work. It's gives DC at usable voltages.

All right, that should work pretty well. Though if it's just Morse code-like signals instead of voices, I might have characters call them "electric semaphores" instead of radios, since that's not what most people think of when you say the word "radio".

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

The Other Wiki crystal radio = cat's whisker radio can be made with lo-tech. Power the transmitter by criminals in a hamster wheel.

What if there were no hypothetical questions? There are 10 kinds of people: those who understand Binary and those who don't.

Indeed, although I believe the actual term was "wireless telegraph", which makes slightly more sense, since you really have to be able to generate electricity before radios make much sense. Also, historically "telegraphy" was the whole concept of moving information without carrying the message there, of which "semaphore" was merely a part.

Or just, you know, a steam engine.

edited 1st Nov '13 10:49:20 PM by MattII

I'm talking about what it's called colloquially, not the scientific name (I'm gonna make it so that radio is developed so soon after electric signals as a whole that telegraphy via wires never got the chance to become widespread).

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

'Wireless telegraphy' was the colloquial name. BTW, the same guy invented both words, and since semaphore got associated with waving flags about, an electric system involving no flags at all is not likely to be called the same thing. No, 'semaphore' is less likely to be used as a name than some completely different replacement for 'telegraph'.

But in the world I'm building, there was never any wired telegraphy (at least not that the average person ever saw much of), so calling the new form of telegraphy "wireless" wouldn't really make sense. And if semaphore is the only form of telegraphy people used before that point, it's only natural that the new kind of telegraphy would be compared to it.

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

Wireless telegraphy without wired telegraphy is a non-starter because it's just too complicated, not only do you need a telegraph key and a speaker, you also need a radio sender and receiver, which aren't easy to build when you've got only a limited understanding of how electricity works anyway. It's like with boats, you wouldn't call a propeller a "perpendicular (paddle-)wheel" just because it rotated to push the boat along, and in the same way, morse-radio won't ever be associated with semaphore despite their doing the same job.

What is possible is that there are so many problems with scaling up wired telegraphy when compared to wireless, that most of the time wireless is replaced as quickly as it can be, thus most people would see the wireless system before the wired one and thus, just call that 'telegraphy', without a prefix.

edited 2nd Nov '13 11:16:09 AM by MattII

Electronic Semaphore just sounds more Steampunkish to me.

I'm not saying there wouldn't be wired telegraphy prior to wireless telegraphy, just that it wouldn't have a chance to become widespread before wireless came around.

And if the country made heavy use of semaphore beforehand, but semaphore towers get shut down as radio towers start being built, it makes sense that people would define this new kind of telegraphy in relation to the old. Like how we still call movies "films", even if they're shot on digital video instead of actual pieces of film. Or how ebooks still have "covers", even though they're not actually covering anything.

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

That would likely be an electric-lit version of the Murray style shutter semaphore.

Maybe, or maybe not, because as I pointed out, they didn't call propellers "perpendicular wheels", even though they'd been using paddle-wheels for quite some time. It's far more likely that they'll come up with an entirely new name for it, than to adapt one that really doesn't fit.

When Josef Ressel patented his design for a propeller he called it, “A never-ending screw which can be used to drive ships both on sea and rivers.” John Ericsson simply called it "Screw Propeller"

The propeller could just as well have been called screws.

Anyway, the word semaphore comes from the words sêma(“sign”) and férō (“to bear, carry”). That's pretty much what telegraphy does. Some even put dot and dashes on paper instead of playing audio to someone that then write it down. So just that propeller analogy doesn't really work.

But yeah, Electronic Semaphore sounds like a electric-lit semaphore.

Maybe "Non-visual semaphore" as it's impossible to see the signal/signs when they are 'carried'? You need a machine in the other end to 'translate' it to audio and/or dot and dashes on paper.

edited 3rd Nov '13 1:15:10 AM by m8e

But would never have been called 'perpendicular wheels', which is in the same line as this discussion, taking a comfortable idea, and then applying to a mechanism that is dramatically different in operation, but similar in result.

Or maybe someone just comes up with a separate word, like Claude Chappe (the man who also invented the word semaphore BTW) did, when he called the whole concept of transmitting messages without carrying them "telegraphy", from the Ancient Greek words tele("at a distance") and graphien("to write").

But when people (in Real Life) hear "telegraph", they think about sending messages over wires, and when they hear "radio", they think about transmitting audio over the airwaves; sending telegraph messages over the airwaves isn't really in the public consciousness. To avoid any confusion, it would be best if I used a different word for the technology (though I suppose "radio telegraph" might work).

As far as colloquial names go, how does something like "spark signals" sound?

"It takes an idiot to do cool things, that's why it's cool" - Haruhara Haruko

Well sure, but that's due to the fact that wire-telegraphs were around for a couple of generations before anyone came up with (telegraph) radio, if you can get radio working at a distance (call it a mile or more) before telegraph, then people will probably mostly forget wired telegraphs even existed.

Works for me. Of course, then radio operations will get called 'sparkies', and we'll have to come up with a new slang name for electricians.