This is amazing to see. I have some audio recordings, digitized from tapes recorded in the 1960s, of my great-grandfather who was raised on a farm in Iowa. He talks about his experiences in amateur radio in the early 1900s-1920s. He mentioned bringing telephones out into the field that could be clipped to the fence wire to make calls back to the house, which was not hooked up to an electric grid but had batteries. Sadly, he did not say how the batteries were re-charged.
MarkusWandel 45 minutes ago [-]
The phone batteries weren't a high load kind of affair. They merely needed to change the varying resistance of the carbon microphone into an audio voltage - on the order of milliwatts of power - to send down the line. A more modern phone, still using a carbon microphone but powered by the line, needed about 20mA of loop current to do this. The telephone terms for the old system vs. the newer is "local" vs. "common" battery.
Heavy duty batteries - specifically the "A" batteries that powered the vacuum tube heaters in early radios - were made rechargeable to save cost.
biofox 5 hours ago [-]
The batteries were either charged using a "telephone magneto", or were taken to a local town to be charged off of mains electricity:
If you look in vintage Sears catalogs - easily found online - I have a printed copy somewhere of the 1908 one and it's definitely in there - aftermarket phones had a bit of a "contraband" aspect to them, and were offered to be shipped in unmarked boxes. Not all local phone companies were "friendly" to people stringing up their own lines.
dmazin 5 hours ago [-]
If you can get your hands on it, I recommend Other Networks: A Radical Technology Sourcebook by the same author. She covers barbed wire as well as many other ways to communicate. The book itself is gorgeous.
There are also discussions about networking over barbed wire.
biofox 6 hours ago [-]
Very cool to see one comment linking to an old Sears magazine from the 1920s, showing some of the equipment people would have constructed these networks from:
The thing I'm most amazed by is how "modern" the catalogue is, especially the clothing and phonograph sections.
zafka 3 hours ago [-]
When I was a kid, I scavenged a hunk of cable "Ma Bell" had left behind. I spliced together a quarter mile pair of wires to connect the neighbors house to mine and hooked up a battery and microphone on one side, and a speaker on the other. No luck. Then we connected the "speaker side" to the input of my friends stereo, and it was possible to be heard. I was about 10 at that time ( ~1970) and was not very aware of voltage drop. The taps and recording system I put in our basement worked much better!
idatum 5 hours ago [-]
I couple years ago I read "A Mind at Play", Soni & Goodman, a biography on Claude Shannon. He grew up on a farm and the book mentions how he made extensive use of barbed wire fence telegraph (and if I recall telephone). Perhaps one of the early experiences Shannon had regarding information.
The MIT Museum had a display (last year) of Shannon's "toys", including the famous mouse maze. I don't recall any mention of his early days using barbed wire telegraph though.
MagicMoonlight 5 hours ago [-]
That’s really cool. I wonder if you could run anything else on a fence network. Like some sort of primitive computer network.
bombcar 2 hours ago [-]
You can run Ethernet over coat hangers, barbed wire should be fine (if slow).
_whiteCaps_ 1 hours ago [-]
You could probably do AX.25 over barbed wire.
torstenvl 6 hours ago [-]
I was really disappointed not to see any mention of Claude Shannon running barbed wire comms in rural Northern Michigan.
eschulz 5 hours ago [-]
As a native of Northern Illinois, I was pleased to see Joseph Glidden mentioned.
Heavy duty batteries - specifically the "A" batteries that powered the vacuum tube heaters in early radios - were made rechargeable to save cost.
https://www.1900s.org.uk/1920s60s-windup-phones.htm
Dry-cell batteries had to be changed, they weren't recharged.
https://www.reddit.com/r/diyelectronics/comments/y7qmhq/15v_...
[0] - https://en.wikipedia.org/wiki/Vacuum_tube_battery
[1] - https://www.wincharger.com/
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
There are also discussions about networking over barbed wire.
https://babel.hathitrust.org/cgi/pt?id=njp.32101066805050&vi...
The thing I'm most amazed by is how "modern" the catalogue is, especially the clothing and phonograph sections.
The MIT Museum had a display (last year) of Shannon's "toys", including the famous mouse maze. I don't recall any mention of his early days using barbed wire telegraph though.
https://en.wikipedia.org/wiki/Joseph_Glidden
Edit: after reading about Claude Shannon, I too think it would have been nice if he was mentioned.
The most powerful geomagnetic storm in recorded history
Likely from the largest coronal mass ejection in modern human history
The natural EMP effect was so powerful, telegraph operators were able to completely disconnect all their batteries and still communicate for hours
https://en.wikipedia.org/wiki/Carrington_Event#Telegraphs
Imagine some future event even more powerful and our dependence on all those LEO sats...