Victorian Radio Discussion

[Lazaras]

Well, this is the birth of the Radio. Just past the victorian era and right before the Great War was when the US started getting its ducks in a row with a dedicated frequency allotment for Amature purposes.

Given I'm (maybe) going to get my ticket back after twenty years of letting it lapse it feels appropriate to poke about here to see if anyone has anything to say about the Marconi Wireless.

So a gentlemen's discussion: Do you count Tesla as the inventor of Wireless, or did Marconi make enough of a contribution that you consider him the inventor?

https://www.youtube.com/watch?v=7QlQ__JzKNI

[mizzarrogh]

Tesla obviously made it possible for Marconi to present the results, but he let him do that and Marconi where good at marketing the inventions instead of just being something lying in another pile of paper nobody really had time to do in depth development of, my guess where Teslas taught. 

I have a small collection of 1920s radios i restored back to functional when i find parts for them.

[RJBowman]

Steampunk prop-builders take notice: none of the early electronic apparatuses shown use vacuum tubes. They simply didn't exist in that era.

[von Corax]

Steampunk prop-builders take notice: none of the early electronic apparatuses shown use vacuum tubes. They simply didn't exist in that era.

Tuuuuuuuuubes!!!

[mizzarrogh]

No, they where open air spark gap transmitters. 
(However, the diod tube was invented 1904 and the "audion" (a primitive detector valve) 1906)
(Neither of those where invented by Tesla or Marconi)
However, before they actually had a very primitive tube called a "coherer(/kohär)" for telegraph detection.
https://en.wikipedia.org/wiki/Coherer
Spark gap:

https://www.youtube.com/watch?v=9zG_DlxyugQ

[John Zybourne]

I hate to be a thread necromancer but unfortunately, I love this topic far too much to refrain from joining the fray. I consider Mr. Marconi the inventor of radio as we know it today. Tesla was a genius of course, but his views on wireless transmission were based around using high voltages to set up earth currents that could be used to send information. Sort of a high voltage version of ideas explored by Dolbear and others. There were proto-wireless ideas floating around in the 19th century, most notably the dentist and electrician Mahlon Loomis who tried to send telegraph messages via ionized air at high altitudes in the 1870's. I still can't find a lot of information as to how his system was supposed to have worked, so I don't know if it was a case of an earlier discovery of radio waves or an idealistic mad scientist overselling his ideas. My hope is the truth lies somewhere in between the two. 

As for Tesla, I'm obsessed with his alleged tectonic agitator.

[J. Wilhelm]

I hate to be a thread necromancer but unfortunately, I love this topic far too much to refrain from joining the fray. I consider Mr. Marconi the inventor of radio as we know it today. Tesla was a genius of course, but his views on wireless transmission were based around using high voltages to set up earth currents that could be used to send information. Sort of a high voltage version of ideas explored by Dolbear and others. There were proto-wireless ideas floating around in the 19th century, most notably the dentist and electrician Mahlon Loomis who tried to send telegraph messages via ionized air at high altitudes in the 1870's. I still can't find a lot of information as to how his system was supposed to have worked, so I don't know if it was a case of an earlier discovery of radio waves or an idealistic mad scientist overselling his ideas. My hope is the truth lies somewhere in between the two. 

As for Tesla, I'm obsessed with his alleged tectonic agitator.

The story of Mahlon Loomis is a rather interested read.  While he was wrong on the electric potential levels of the atmosphere, the idea of telecommunications based on atmospheric layers is a common denominator with shortwave long range transmission, in that radio waves bounce off the ionosphere with an greatest efficiency around 28-30 MHz (near CB radio bands oddly enough).  T'was Charles Samuel Franklin, assistant to Gugliemo Marconi, who in the early 1920s made the first long range radio transmissions based on this concept.

Transmission in the range 1 MHz to 30 MHz is what we knew as Shortwave radio (past tense, because I don't know how many young people, if any, still know about this technology), which allows intercontinental and global radio transmissions, some of them digital as well.  By the 1980s, when I was in highschool, many of my classmates didn't even know Shortwave existed!  Imagine now!

I'm curious: How many of you have ever used a shortwave radio?

[John Zybourne]

I'm a shortwave enthusiast myself. I'm definitely the youngest person at my local amateur radio club though. I have a 15 year old portable Grundig receiver and have been trying to build my own crystal shortwave receivers on and off for some time. Ionosphere skip is a really interesting phenomena and one that still has a lot of mystery around it. Long delayed echoes, radio echoes where a transmitting station hears its transmission echoed back to it after a delay of 2.7 seconds or greater are one that comes to mind. They were first noted about a century ago in Norway and to this day there isn't a consensus as to what causes the effect.   

[mizzarrogh]

I used them a lot whan i was a kid, before the Internet was easily available as today. 
I still hawe a few receivers in functional state, but it's mainly Russian fishermen and communal workes who use the open shortwave bands today here, not so much open Military or civil deffense things going on this way which can still easily be owerheard by regular old fasion DX equipment today, at least not in my country. But i still love to dust en off in the evening, particulary now in the dark winternights whan the snow and ice are blocking everything outdoor.

[J. Wilhelm]

I used them a lot whan i was a kid, before the Internet was easily available as today. 
I still hawe a few receivers in functional state, but it's mainly Russian fishermen and communal workes who use the open shortwave bands today here, not so much open Military or civil deffense things going on this way which can still easily be owerheard by regular old fasion DX equipment today, at least not in my country. But i still love to dust en off in the evening, particulary now in the dark winternights whan the snow and ice are blocking everything outdoor.

I'm a shortwave enthusiast myself. I'm definitely the youngest person at my local amateur radio club though. I have a 15 year old portable Grundig receiver and have been trying to build my own crystal shortwave receivers on and off for some time. Ionosphere skip is a really interesting phenomena and one that still has a lot of mystery around it. Long delayed echoes, radio echoes where a transmitting station hears its transmission echoed back to it after a delay of 2.7 seconds or greater are one that comes to mind. They were first noted about a century ago in Norway and to this day there isn't a consensus as to what causes the effect.   

Have you guys seen the new generation of software defined ham radios?  I'm just learning about it. It seems that at least hobby wise SW is not dead. Of course higher frequencies are more popular now, but I'm impressed at the hardware available today.

[von Corax]

I used them a lot whan i was a kid, before the Internet was easily available as today. 
I still hawe a few receivers in functional state, but it's mainly Russian fishermen and communal workes who use the open shortwave bands today here, not so much open Military or civil deffense things going on this way which can still easily be owerheard by regular old fasion DX equipment today, at least not in my country. But i still love to dust en off in the evening, particulary now in the dark winternights whan the snow and ice are blocking everything outdoor.

I'm a shortwave enthusiast myself. I'm definitely the youngest person at my local amateur radio club though. I have a 15 year old portable Grundig receiver and have been trying to build my own crystal shortwave receivers on and off for some time. Ionosphere skip is a really interesting phenomena and one that still has a lot of mystery around it. Long delayed echoes, radio echoes where a transmitting station hears its transmission echoed back to it after a delay of 2.7 seconds or greater are one that comes to mind. They were first noted about a century ago in Norway and to this day there isn't a consensus as to what causes the effect.   

Have you guys seen the new generation of software defined ham radios?  I'm just learning about it. It seems that at least hobby wise SW is not dead. Of course higher frequencies are more popular now, but I'm impressed at the hardware available today.

Hackaday regularly have articles about software-defined radio, especially for sniffing 433 MHz devices, and they have an occasional series called "The $50 Ham" although it hasn't updated recently.

[mizzarrogh]

I am still learning, but i see a lot of oportunities in it, particulary when one can see full spectrum diagrams, 3dimmensional flow, etc
One thing i want to do is to setup mu old laptop as a device for tracking down weather baloons.
A radio telescope would also be awesome!

Maybe i should take a picture, but i recently picked up what i think may be an actual antique scool demonstration model of a spark gap before the radio era.

[RJBowman]

What I learned from this film: spark-gap transmitters are illegal in the United States.

I remember seeing illustrations and descriptions of them in books on electricity when I was a child. If I had been a little more competent at building things back then, I probably would have built one, and unknowingly violated U.S. law.

[mizzarrogh]

They are illegal in Europe too, tecnically because old ship radiostations did jam the band for the newer type of transmitters in the 1920s, but with this low output power i don't think it would be an issue under normal circumstanses. Just for demonstration purpose one does not even need to use an actual antenna, it's probably a lot more more disturbance from runing an electric teapot i think.

The old ship transmitters had giant antennas which where like 15-30 meters wire or more and the transmitter had to be ramped up substantialy in order to achieve a reasonably useful operating range because of the massive transmission loss + it could not realy use a proper output amplifier stage as they did in the 1920s. The extreme energy consumption and bad range was probably the real reason they where phased out less than a decade from when they came out. In the 1920 proper output amplifiers where available with the new type of closed tube transmitters and the long wave system was established allredy, so i think the old sparkgap system simply fell out of practical use long before it was forbidden.

But, for a fantasy steampunk world it is almost a must to hawe big balls with large sparks... 

[mizzarrogh]

The law was whas probably because a sparkgap transmitter did only cost a small fraction to make compared to a valve transmitter at the time and they probably wanted to limit them being used in large numbers on fisherboats and other small ships and land stations which could not realy afford to setup a valve transmitter station.

[J. Wilhelm]

I am still learning, but i see a lot of oportunities in it, particulary when one can see full spectrum diagrams, 3dimmensional flow, etc
One thing i want to do is to setup mu old laptop as a device for tracking down weather baloons.
A radio telescope would also be awesome!

Snip

Who would have thought weather balloons would turn out to be so threatening 😉 Now everybody is hunting for them!

Personally, I think recent events will reignite interest in lighter than air craft. Now that's a long time running topic for this forum!

[mizzarrogh]

It's interesting to think about the fact that both gas and hot air baloons with capacity of carrying multiple persons on high altitude had allredy been up and runing for about 100 Years in the Victorian time.

Spark gap coil machines did exist long before the spark gap radio, i hawe several in my own collection, at least two of them date back to the 1880s when that particular model first was in production, but i think the earliest ones where made allredy in the late 1700, even if it was not until Michael Faraday the modern type of coils came, the modern high voltage coil (the mother of all ignition coils... :-) ) was originaly invented by Heinrich Daniel Ruhmkorff  https://sv.wikipedia.org/wiki/Heinrich_Daniel_Ruhmkorff  Shortly after as an extension of Faradays work.

[mizzarrogh]

However, the most important of Ruhmkorffs calculations was probably to pave the way to the conclusion that there is only one type of electricity, not two different types as many scientists taugt in the 1860s whan Jules Verne wrote the books which mention those both type; "common" and Static electricity, by ramping up the voltage with help of a transfomer which allows that, the outcome will be as we know today that the secondary output will be transformed to an equvivalent to static charges the human eye may notice, and it was also possible to reverse the process and transform high voltage to low voltage as we take for granted today.

[von Corax]

The law was whas probably because a sparkgap transmitter did only cost a small fraction to make compared to a valve transmitter at the time and they probably wanted to limit them being used in large numbers on fisherboats and other small ships and land stations which could not realy afford to setup a valve transmitter station.

I think the issue is that a spark-gap RF source emits radiation and interference over a very broad bandwidth, making many adjacent channels unusable.

[mizzarrogh]

Yes of course, badly written by me...
Exactly the same reason long wave was banned in modern time (except for very specific military use).

The very early transmitters did as far as i know not operate in any define spectrum (as the later ones did), they served only as an open radio telegraph unit i think, as far as i know they can not jam each other except then by an exact collision in a critical moment. But as You said that quickly became a safety problem when the number of senders in use simultaneously rapidly increased, and about 5 years later the tecnology made it possible to use a reasonably defined bandwidth.

[mizzarrogh]

I think the first regulation (at least from what i heard) was because a more powerful transmitter would automaticaly owerpower a weaker transmitter and litterary jam all wireless comunication in it's closer range during the operation process.

[J. Wilhelm]

It's interesting to think about the fact that both gas and hot air baloons with capacity of carrying multiple persons on high altitude had allredy been up and runing for about 100 Years in the Victorian time.

Depends on how you define "high altitude." Relative to the weather balloons in the news lately, no craft I know of ever reached the same altitudes. In my opinion, it was easier from an engineering point to manufacture the envelope than the gondola, avionics, and life support, because the real obstacle back then was knowledge about the directly measured properties of the atmosphere. Temperatures in particular and lack of oxygen would have been the primary challenges.

In terms of engineering, the materials available could possibly handle the size of the envelope. Yet, none of the early 20th century dirigibles, for example, ever reached the stratosphere.  An envelope for such altitude needs about 3 times the volume (if I remember correctly) to maintain the same buoyancy as an envelope at say, 30 kft, which is more or less airliner cruising altitude. One British research balloon did in fact attempt to reach those altitudes, but the research party nearly died due to lack of oxygen and the cold.

Calculations:

Off-Topic: ShowHide

In static equilibrium, weight, W must match buoyancy, B.

B-W= 0

Noting mass is equal to density times volume m=ρV, let index 1 be sea level, and 2 be 30 kft, average beginning of stratosphere (it varies greatly with latitude, as low as 20kft at the poles and 60 kft at the equator). For reference, the Chinese balloon was flying at 60kft, and the other two over Alaska at around 40kft. Airlines fly at around 35kft. At 30kft the density of air 0.37 times that of air at sea level.

Buoyancy B=ρVg
g= gravitational constant
V= volume of fluid (air) displaced by envelope
ρ= density of fluid displaced (air)

B1=B2
ρ1V1g1=ρ2V2g2

g1~g2 (gravity falls very slowly as a function of altitude)

Therefore if ρ30kft/ρ0ft ~0.37
V2/V1 =ρ1/ρ2 ~2.7

At 30 kft the temperature falls to -44 °C or -47°F

It's absolutely shocking, but from what I remember, research in earnest on the structures of the atmosphere didn't start until the 1930s! So equipment for high altitude flight didn't exist before then.

The first people to successfully enter the stratosphere were Swiss physicist Auguste Piccard and his assistant Charles Kipfer, who flew to an altitude of 15,781 m (51,775 ft) on 27 May 1931 in a gas-filled balloon designed by Piccard. Prior to that event, the "uncontrolled" attempt I mentioned above was made by the British scientists James Glaisher and his assistant Henry Coxwell on 5 September, 1862. It's unclear to me why their attempt doesn't count as a successful entry into the stratosphere, though, when they did reach 37 kft of altitude.


https://www.bbvaopenmind.com/en/science/leading-figures/auguste-piccard-the-versatile-explorer-from-the-sky-to-the-bottom-of-the-sea/

https://www.bbc.com/future/article/20160419-the-victorians-who-flew-as-high-as-jets

This is something I've been researching (since time immemorial, apparently) for my never-to-be-finished pet project "The Valkyrie and the Eagle." Basically I have to figure out an excuse as to why mid 19th century people would even be interested in exploring the atmosphere over the stratosphere and beyond.

[mizzarrogh]

No, but still impressing how far they managed to take it with the tecnology available in the 1890s. 
Gaston Tissandier did however  try to reach the actual Stratosphere.
The first sucessful actual Stratosphere flight where, as far as i know, not until 1931 with Auguste Piccards pressure chamber Aerostat (mainly because he finaly had acess to materials who could withstand the gas expansion better without taking up too much weight ( Jacques Charles and the  Robert- brothers 1783 constructed the very first unmanned hydrogen baloon but it did rip apart from the high altitude gas expansion in the early prototype demonstration stage, it was not until the late 1800 new materials made it possible to touch the border of the actual stratosphere as far as i know).

The first weather balloon was released in 1892 by Gustave Hermite
(I hawe always been deeply interested in weather and stratospehere probe balloons since i was a little child, long before the modern hype, they where the poor mans rockets in the early days and still are for some short span LE civil reserach missions, et least in my country stratosphere balloons are still in active use from time to time. Since the 1940s they are however partly replaced by sond rockets, for better altitude reach, in my country. BTW, Alfred Nobel did experiment with reusable black powder rockets allredy in the 1890s and thanks to Gustaf de Lavals general calculations for supersonic injectors (originaly for high pressure steam turbines) it was possible to construct the modern bell shaped rocket engine as we know it today (I think Robert Goddard did use it a lot actualy, he must had realised the future potential of it (the bell is only to get some extra horses from the engine, it's not the actual nossle, it was further developed to it's modern form by Konstantin Tsiolkovsky, (paralell with Goddards work), even if neither of them did the formula or designed the supersonic nossle both of them clearly did a good chunk of the early fieldwork paving for developement of the modern rocket engine as we know it today (the modern high pressure compond fuel rocket engine did not come until the 1920s, but Goddard and Tsiolkovsky managed to construct functional models for low pressure liquid fuel before that, as far as i know many of the models did actualy take off and flew shorter distances without problem, but they where not yet powerful enough to (in theory) reach space until Von Opels team developement, however Tsiolkovsky drawed a lot of manned spacecraft vehicles on paper drawings. ).). )

[J. Wilhelm]

No, it's not the actual nossle, it was further developed to it's modern form by Konstantin Tsiolkovsky, (paralell with Goddards work), even if neither of them did the formula or designed the supersonic nossle both of them clearly did a good chunk of the early fieldwork paving for developement of the modern rocket engine as we know it today (the modern high pressure compond fuel rocket engine did not come until the 1920s, but Goddard and Tsiolkovsky managed to construct functional models for low pressure liquid fuel before that, as far as i know many of the models did actualy take off and flew shorter distances without problem, but they where not yet powerful enough to (in theory) reach space until Von Opels team developement, however Tsiolkovsky drawed a lot of manned spacecraft vehicles on paper drawings. ).). )

We simply know it as the Converging-Diverging nozzle. As the gas expands from a stagnation pressure (maximum where ignition takes place in case of rocket engines) the gas is accelerated by a converging shape. As the gas approaches the speed of sound toward the neck of the nozzle a transformation occurs where the gas becomes more pliable and expands or contracts "on command" according to the shape of the tube. The neck is where you reach Mach 1, the bell, continues accelerating a now pliable gas flow, ideally continuing the drop of pressure to match ambient pressure.  That match only happens at one altitude, so you have to "tune" the bell to the particular altitude you need. Outside of that altitude efficiency drops.

In aerospace engineering you end up leaning about this at the same time you take your first class in compressible flow (supersonic flow). It's one of the first lessons in propulsion.

[mizzarrogh]

Correct, but the spike and knife edge did not as far as i know came in the picture for real until the 1960s. 
I am on the hobbyist level among those who fly plastic rocket models on the fields and DX in my hobby room to be honest, netiher am i a real collector of antiques, i mainly collect cheaper things i like to study how they where made back in the days and hawe as a referense (for example the Ruhmkorff apparates, and they still work and produce sparks after more than 130 years! I wonder how many modern apparates will still be fully functional after 100 years... ) , but it is indeed an old childhood dream to build a liquid fuel engine, however a modernized replica of for example one of Goddards demonstration models would be in reach to achive even with "garage equipment" i think.

Not realy steampunk, but 1940s SiFi, but i am still a big fan of Eugen Semitjovs cartoon books whan it come to estetic spacecraft design, unfortunatly i only managed to get one collection book so far, they are quite hard to find, but i hope they will be digitalized in the future, but i must admit that there is something more to sit down in grandmas rocking chair with an old scool paperbook compared to sitting in front of a computer/cellphone screen and trying to read a book.

Whan i was a kid i did draw the historical line exactly with the year 1900 for things i concidered as genuine, but since stempunk is not realy by any means historicaly correct i don't think there is any major issues to mix in later elements if one so desire. Personaly i love to use actual 1800 SiFi pictures and try to remake them into reasonably functional with today existing tecnology but as close as possibly to what they in another universe or so could had achieved in their own time, 1940s rockets still had skeletal frame and a lot of rivets and bolts to them for example, they are very easy to punk up a bit if one want to use rockets in the 1800 alternative universe for example.