[HN Gopher] How photos were transmitted by wire in the 1930s
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How photos were transmitted by wire in the 1930s
Author : bookofjoe
Score : 215 points
Date : 2024-03-13 11:53 UTC (11 hours ago)
(HTM) web link (kottke.org)
(TXT) w3m dump (kottke.org)
| xattt wrote:
| Tangential, but was there ever some form of fibre or telephony
| connection for news crews in 1990s? Microwave trucks excluded.
|
| I ask this because I swear, as a kid, I've seen a cameramen open
| up a telecom/telephone box and connect something to it. I assumed
| it was for an uplink back to the station to transmit video.
| lebuffon wrote:
| Absolutely. From the advent of radio broadcasting telephone
| lines were used for everything, audio and even DC signalling to
| control relays. All remote radio broadcasts used at least two
| lines. One for sending sound back to the station and a 2nd pair
| (telephone lines are a balanced pair of wires) for "cue" that
| came from the master control room to the remote site.
|
| Since most transmitters were located outside of city limits,
| equalized telephone lines were used to send the sound from
| master control to the transmitter.
|
| This was the most common and cheapest way to make the
| connection to the transmitter until the advent of inexpensive
| microwave equipment. And microwave links have a nasty habit of
| fading out during tropospheric inversions so they were actually
| not as reliable, over long distances, as a phone line with a
| backup phone line that took an alternate path. (first hand
| experience here. Ya I'm that old) :-)
|
| Most people today have no idea how you transmit analogue audio
| faithfully and reliably over long distances, via wires.
| Telephone engineers figured it out over 100 years ago.
| riffic wrote:
| they would have had the operator reverse the charges I
| assume?
|
| by the way the old bell system technical journals are a fun
| read and are generally available at places like archive.org
| ikiris wrote:
| I know ISDN was used for this kind of thing for a good while.
| lebuffon wrote:
| Yes, ISDN was the higher priced product offered by the telcos
| but ISDN was not available until the 1980s. Radio
| broadcasting started over 60 years earlier and analogue lines
| were the only option.
| subpixel wrote:
| This is also how live radio broadcasts were made. I'm old
| enough to have been a part of shows performed at the West End,
| mixed across the street in the studio, and broadcast from the
| World Trade Center downtown.
| rightbyte wrote:
| In it's simplicity it is genius. I had no clue this was a thing.
|
| https://en.m.wikipedia.org/wiki/Wirephoto
|
| I really like these old "explaining" films. The pedagogical level
| is far higher than what seems common today. And the they take
| their time to convey the message.
| mhuffman wrote:
| >I really like these old "explaining" films. The pedagogical
| level is far higher than what seems common today. And the they
| take their time to convey the message.
|
| I wonder what happened? I have been blown away by some of the
| older explainer videos from the 40s and 50s, esp. some of the
| military training videos for vehicle repair, electrical
| engineering, etc. Very concise and very clear explanations,
| always with visual examples. Today, we have things like
| 3brown1blue that are kind of like that, but in general you
| don't see information transfer like this either online or in
| school (at least not in my experience).
| Osiris wrote:
| The one about how a differential works is fantastic. It just
| goes step by step through showing the problem to incremental
| improvements until the final gearing system is "simple".
| BurningFrog wrote:
| My guess is that back then producing films was expensive
| cutting edge technology, and the few films that got made
| hired the brightest and best, and gave them time to get it
| right.
|
| Today any unemployed bozo can make explainer YouTube videos.
| That great as a "democratization", but the average quality is
| obviously lower.
| SoftTalker wrote:
| They were produced to convey information, not to generate
| clicks and ad views.
| cm2187 wrote:
| Youtube is full of videos like that. A few sample excellent
| channels:
|
| https://www.youtube.com/@animagraffs
|
| https://www.youtube.com/@engineerguyvideo
|
| https://www.youtube.com/@Lesics/videos
|
| The problem is more that they are drowned under the volume of
| content available.
| pjerem wrote:
| Also Jared Owen which does an impressive work of 3D
| modeling to explain how things and places work. I'm amazed
| by the level of documentation you have to ingest to model
| things in such details.
| Gerard0 wrote:
| Wow, thanks for sharing!
| sema4hacker wrote:
| If YouTube had a Dewey decimal style clickable directory it
| would be a lot easier to find content.
| jimbokun wrote:
| Those videos were the equivalent of 3brown1blue for their
| day. With YouTube, there are far more videos of this sort
| today than there were then.
| roywiggins wrote:
| Yes, however, nobody has (imho) done it better than The
| Secret Life of Machines did it back in the late 80s/early
| 90s:
|
| https://www.youtube.com/watch?v=yuUyt9RG7pk
| ClassyJacket wrote:
| Have you seen Technology Connections on YouTube?
| xandrius wrote:
| Yeah, a bit dry and it doesn't always hit the spot with the
| tone.
|
| I wanted to like it but couldn't.
| chiph wrote:
| It's simple, yet hard to execute well. Each sentence contains
| one piece of information to be imparted. The speed of
| speaking is slower - with emphasis on diction and
| pronunciation. There is a slight pause between sentences to
| allow the recipient time to comprehend what was just said.
|
| Try it yourself - read some of the comments here in that
| manner and observe the difference.
| nonameiguess wrote:
| I pretty much use YouTube as a MTV replacement to watch music
| videos only, so won't speak to the quality of instructional
| material you find there, but I was still in the military as
| recently as 12 years ago and the training material in the
| military was still terrific. This includes unclassified
| material, though I don't know how you'd find it as a civilian
| if, for whatever reason, you were interested in learning how
| to perform maintenance on a modern humvee or what not.
|
| The technical manuals are all available through Army epubs,
| but even though they're not classified, you still need a
| common access card to login and use the site. A lot of them
| get mirrored somewhere the public can find them, but I would
| definitely not call the sprawl of where you might find them
| very searchable.
| mrandish wrote:
| > The pedagogical level is far higher than what seems common
| today.
|
| This is a growing pet peeve of mine. I used to think that
| advancing media formats and productions tools would generally
| make conveying knowledge faster, better and deeper. Instead, we
| see most media intentionally engaging in overall
| 'dumbification'. It's not just more content being shorter or
| more summarized, as I'm trying to compare 'apples to apples'
| here in terms of content targeting, length etc.
| anonymoose33282 wrote:
| What's interesting is you also see the is was sponsored by
| Chevrolet (on the title screen), so it seems monetization-
| wise, it's no different than today when YouTubers have a
| sponsor read at the start of a video. I just wonder if then
| it's simply a matter of more creators competing for less ad-
| money-per-person, which leads to the kind of "optimized"
| content we see today.
| Narkov wrote:
| Does survivor bias account for this? Only the best/most
| worthwhile videos from the "old times" are archived.
|
| Right now, we see every piece of crap uploaded to YouTube. No
| doubt there's awesome video content being created today -
| Smarter Every Day by Destin Sandlin seems to fit - but it's
| surrounded by junk.
| caditinpiscinam wrote:
| A couple other good ones:
|
| How Differential Steering Works (1937)
| https://www.youtube.com/watch?v=yYAw79386WI
|
| Flak (1943) https://www.youtube.com/watch?v=H8zPNMqVi2E
| rightbyte wrote:
| The diff one is so good.
|
| Note how they made a model in the wirephoto video too to show
| the concept but with painted rope.
|
| Models seems to me to be a very good pedagogical tool.
| causi wrote:
| AT&T's "Similarities of Wave Behavior" is incredible.
| Animats wrote:
| That's Jam Handy. They were really good at that.
|
| Some Youtubers should try that style. Neckbeards with
| headphones are so over.
| rdlw wrote:
| Not sure what you mean by that but Steve Mould
| (physics/chemistry/engineering), Matt Parker (math), Primer
| (economics), AlphaPhoenix (electricity, lately), 3Blue1Brown
| (math), Fraser Builds (history of chemistry, alchemy), Ben
| Eater (computers), Gneiss Name (geology) and The Thought
| Emporium (genetics/miscellaneous) are some youtube channels I
| really enjoy that teach concepts by either making elaborate
| models, making elaborate animations, or just actually making
| the thing they're talking about from scratch.
| Animats wrote:
| The hard part was synchronization. We're used to
| synchronization being easy today, but it was really hard to
| synchronize anything until the 1980s, when phase-locked loops
| became easy and cheap.
| rightbyte wrote:
| Does the belinograph need syncing though? I imagine you would
| just have a waste ribbon around the photo and start it after
| the call with say a delay you both agreed too. Or maybe you
| could send light in some known pattern with a starter strip
| and the receiver could look at the lamp.
|
| Attenuation most have been a problem though? I guess you
| could send some sort of calibration photo to adjust gain? I
| don't think practical FM signal modulation was a thing yet in
| the 30s?
| barrkel wrote:
| You need to synchronize the spin rate of the drums on
| either end. If there's a difference of half a rotation over
| however many hundreds (thousands?) of rotations to transmit
| the photo, you'd end up with a completely distorted
| picture.
| jnewkirk wrote:
| I had a pair of these transceivers when I was in my teens,
| from a somewhat later period, thanks to my grandfather who
| refurbished them from his time as a telegrapher at Western
| Union. Synchronization at startup took ten seconds or so
| while each unit adjusted its timing and apparently sent a
| correction signal to the other, drums whirling all the time
| and gradually matching initial positions. It looked like the
| most primitive process possible, but worked every time.
| barrkel wrote:
| Yes, I was looking for the bit where they addressed skew. You
| can even see it in the demo with the string, horizontal lines
| come out wavy after transfer to the other spool due to small
| differences in synchronization.
| ugh123 wrote:
| > The pedagogical level is far higher than what seems common
| today. And the they take their time to convey the message.
|
| I think that is true for some content, but there's certainly a
| contingent of content creators out there now putting out a lot
| of good technical explainer videos. They're doing it far better
| than your typical mass media content producers.
| sgc wrote:
| I agree completely. I have found so many great videos for
| woodworking, coffee (both roasting and espresso brewing),
| robotics, home construction, car repairs, computer/portable
| device repairs, etc. Youtube has made almost any hands-on
| activity so much easier for me to learn.
|
| I prefer reading for theoretical concepts most of the time,
| but something more complex that I don't have the time to
| properly study is sometimes better served by a good video or
| series as well.
|
| Practically, most everything I dig into it's using both,
| although I just now started using phind.com (thanks for the
| tip HN) to fill in some of the things all my sources seemed
| to be skipping over or presupposing, and that has helped me
| get answers to latent questions I had for quite some time. I
| really need those links out because I can't rely on AI
| generated information otherwise, of course.
| kgwxd wrote:
| OT but one of my favorite songs is made from an old video like
| that https://youtu.be/Azsk21MpbUk?feature=shared
| roywiggins wrote:
| Possibly the high water mark of such things was the "Secret
| Life Of Machines" series. Here is their episode on fax
| machines:
|
| https://www.youtube.com/watch?v=yuUyt9RG7pk
| ikiris wrote:
| That is some electric age magic and is really neat.
| at_a_remove wrote:
| I have some old wire photos in a particular set of movie
| memorabilia I've been constructing from press kits, pamphlets,
| film cells, foreign posters, slides, lobby cards, et al.
| ThePowerOfFuet wrote:
| Original source link: https://youtube.com/watch?v=cLUD_NGE370
| caditinpiscinam wrote:
| How did they get the incandescent bulb on the receiving end to
| switch on and off fast enough to avoid blurring the picture?
| clintfred wrote:
| I think the video said it was a neon bulb, which reacted "fast
| enough".
| waltwalther wrote:
| A neon tube was used on the receiving end because it reacts
| more quickly to current. This is mentioned at about 6:45 into
| the video.
| zdragnar wrote:
| The video explains that they used a neon bulb, which is far
| more reactive to current changes than standard incandescent.
|
| Incandescent lights produce visible light largely through heat
| of the filament, whereas neon lights emit by passing current
| through the gas, meaning that rapidly changing the current is
| more effective- the had e doesn't need to cool down like a
| filament to stop producing light.
| asimpletune wrote:
| That scene (around 3:45) with the two, coupled spools of rope
| that transmit the picture from one spool to the other is simply
| amazing.
| abrookewood wrote:
| Agreed - really conveys what is happening in a simple and
| effective manner. It's a great addition to the video.
| fanf2 wrote:
| Fax machines go way back to the 1800s, before phones,
| surprisingly old! Another classic is Tim Hunkin's secret life of
| the fax machine https://youtu.be/yuUyt9RG7pk which features a
| clip from the video in TFA.
| maxlin wrote:
| I love this. It's so immensely simple. Truly human technology.
|
| We need to burn all computers and limit technology to this level.
| thfuran wrote:
| I think you may have gotten a bit carried away.
| insane_dreamer wrote:
| Long live the Butlerian Jihad!
| goatlover wrote:
| The spice must flow!
| ornornor wrote:
| Crazy what we had to do before fully digital circuits.
|
| Also, that GO/STOP traffic "light"!!!
| ajb wrote:
| Even older is Jacquards self portrait on 24000 punched cards - a
| 2Mpixel image in 1839
|
| https://en.m.wikipedia.org/wiki/Joseph_Marie_Jacquard
| anovikov wrote:
| 1930s? These machines were widely in use even in the very end of
| the Soviet era like in 1989 or so, in the USSR. I personally seen
| them in operation in post offices being a kid. I think the very
| last of them fell out of use when modern faxes appeared but just
| like telegrams existed for a while when email was already a
| thing, i think these stayed formally available even if not in
| demand, well into 1990s.
| IvyMike wrote:
| For a slightly later version of this: My most popular YouTube
| upload is the telecopier scene from Bullitt, where you can see
| the police use the latest and greatest "fax" technology of 1968.
| I uploaded the video without almost no information, but in an
| surprising twist, a lot of the youtube comments are actually
| pretty informative.
|
| https://www.youtube.com/watch?v=nQGAaCSFlJI
| mikehollinger wrote:
| This is remarkable. Lasers were invented in 1960 as a point of
| reference.
|
| The painted rope on two spools was also remarkable because of its
| simplicity - and it holds up today on explaining what a
| "download" is. ;-)
|
| And even cooler - if we wanted to, I would wager a high school
| student could implement something along these lines using lego
| today. There's optical sensors, and you could rig up something to
| hold a pen like this [1] to render the image.
|
| [1] https://www.youtube.com/watch?app=desktop&v=dHmgaLgFRGM
| petee wrote:
| A neat variation from the era is Hellschreiber teleprinter,
| graphically prints the characters using a spinning head that
| impacts the tape strip, which results in readable messages even
| with heavy interference
|
| https://en.m.wikipedia.org/wiki/Hellschreiber
|
| Edit: some ham radio operators still use it for fun, and I'd
| heard that one of the SDR decoders can read it
| drmpeg wrote:
| With SDR, you can paint an image into the receiver waterfall
| with OFDM.
|
| https://www.youtube.com/watch?v=saac0ZtTeX4 (be sure to switch
| to 1080p)
|
| https://github.com/drmpeg/gr-paint
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