Fun fact about that air raid siren you were standing in front of, it’s made by Chrysler and sports a Chrysler V-8 331-CID Hemi Engine And the siren has a Decibel Output of 138dB at 100 feet, it’s definitely one of the most distinct sounding sirens so when you hear it go off you know exactly what siren it is by the tone of the wail!
Would love to acquire one of these units! A true classic and a real sound blaster! The newer Federal Signal and Whalen voice over sirens are nice as well!
1. Wow this was exactly the amount of information I wanted when I clicked the video 2. You’re on the top of my list for if I ever visit Seattle yet somehow I wasn’t subscribed to your channel‽
There's nothing worse than getting your hand shocked on connections on a wirewrap block on a frame and jerking it forcefully driving the back of your hand into the block next to it and getting shocked again.
It would have only happened once with the equipment I worked with High voltage DC at enough current to set you on fire. One transmitter used 7,000VDC at over 5 A for normal operation,. The filaments in the final tubes were 1.5V @ 1000A each so that was 3KW f ac current per tube. One would set you on fire, the other would melt any tools that got in the way.
Bonus points for doing the "There are four lights" routine from Star Trek TNG. (Though it must be considered obligatory when actually talking about four lights!) 😁
I went to school at Arizona State University in the late '80's. Every Saturday at noon, the air raid siren on the hill to the north of campus went off during its weekly test. Us dorm dorks referred to it as the "hangover check." This siren had a rotating horn assembly to extend the reach of audibility. As the siren went through the test, you could hear the sound volume (the actual volume, not warbling) change as the rotation came up to speed, became steady, then slowed back down to a stop. On particularly bad Saturdays, it would come to rest with the business end pointing straight at campus, so you got to listen to the siren at full volume until the siren itself finally spun back down. Great video. Thanks for the fantastic history lesson.
The Defense Switch Network, the successor to AUTOVON, is still very much alive and well today! We even still have the same 4 priority levels (Priority, Immediate, Flash, Flash Override) that you can use on DSN calls.
Which go through the red switch network. Digitized in the '90's, rendering the old AUTOVON network obsolete. I remember our staff meetings, initially IA getting to go after red switch briefed on their status, but after some rather high profile events, IA got to go before red switch had nothing to report. We did have red switch go down twice at one installation and well, due to that installation's purpose, theater wide. Once, due to a generator failure, the other, a transformer fire, both triggering failover to the building UPS that was inoperable until the generators could come online. A longstanding issue of a room full of defunct batteries was swiftly addressed after the second time the general's phone stopped working... I still remember siren codes. Warbling wail, a warning. Pulsating, strike incoming soon. Continuous, strike imminent. Goes back to warble, all clear. 3 - 5 minutes duration. Adapted in many areas to warble a warning, continuous typically being a tornado is about to relocate your furniture. But, all derived from the military system, which had a few additional tone codes, before we all ended up with computing devices attached to our gonads. ;)
There was a "Bells & Lights" box in the office of my elementary school, just outside the principal's office - where I often sat waiting to "discuss my attitude problem". I was fascinated by every part of it down to the _Private Line_ sticker on the connector block.
I had much the same experience! I remember one fine day when i was sitting there and it rang, quite loudly. I asked the office staff what that thing was but they either didn't know or didn't want to engage with the kid in detention, but they declined to explain. I guess I've been waiting for this video for over 50 years! Thanks to Sarah et al for posting it. I also have memories of the air raid sirens wailing their monthly test run. A kind of eerie feeling as the waves of sound from multiple sirens cascaded over the city.
I remember drills in elementary school. Crouch under your desk, face away from the windows and put your head between your knees. We used to joke .. 'and kiss your ass goodbye'
@@jimurrata6785no memory of those, they ended shortly before I went to school. But then, I was born a week after Tzar Bomba was detonated. But, after starting a lengthy military career, in nukes initially, I've a different mode of address to a nuclear warning. "Go to the light, my children!" And I live now at pretty much ground zero, a state capital, a couple of blocks from the governor's residence, in a region ringed with military supply depots and communications nodes. A hint for the curious, I miss a major navigational landmark that's now gone for a hand span of years, the plume from Three Mile Island.
@@spvillano Steam from a cooling tower is pretty empherial, for a landmark. I remember the meltdown. People where I was (NYC) were concerned if the containment burst. Thankfully we didn't have a situation like in Ukraine.
@@jimurrata6785indeed! I was in Delaware County, just south of Philly when it melted down. Hollywood reliably informed us a week before that Pennsylvania would be uninhabitable. So, per Hollywood, I guess that I'm dead or something. ;) Chernobyl, well, that was quite the series of errors, from construction with an inflammable roof (specified to not be so in their plans) onward. Yeah, one of their specifications was for a non-flammable roof. So, corruption ensued, flammable roof installed.
Went to High School in the mid 1960s in Kenai , Alaska where there were White Alice antennas locted 25 miles north of town. I had a mobile CB radio in my VW bug and found that finding the sweet spot in front of the White Alice antenna allowed my to converse with other CB operators in Japan when " Skip Signal conditions were present.
My father worked on the White Allice site outside of Kotzebue, AK. I've visited the site, which I believe you pictured. (As well as the "Kotzebue National Forrest" :) He was also one of the lead engineers for RCA / Alascom that designed the microwave and satellite communications systems to bring modern communication to remote Alaska villages. All of this was an immense undertaking to build. It kept my father flying around Alaska in his Cessna for the better part of 15 years. Thank you for bringing the history of this system to everyone. It brought back warm memories seeing these photos again.
Many places in “tornado alley” still maintain similar systems to this day. Here in Indianapolis they go off every Friday around 11 a.m. Instead of nuclear missiles, they warn people of dangerous weather like, as the name of the region may suggest, tornados.
I live in Saint Cloud Minnesota and they have Federal Signal 2001 sirens they test once a month and the National Weather Service tests the Weather Radio alert system every Thursday at 1 pm.
Yah, here in Minnesota, they audibly test the "tornado sirens" at 1 PM on the first Wednesday of every month. Also, the first full week of April is Severe Weather Awareness Week here. And on Thursday that week, the sirens sound statewide at 1:45 PM and 6:45 PM for the statewide tornado drill.
I've been around telecom my whole life - my dad worked for Michigan Bell for 30 years - and I've always been a Civil Defense buff. This video is a double whammy for me!
I'm just think how that little maneuver @13:17 could have been enhanced with a properly timed slide whistle. Another fantastic educational video. Thanks and keep it up!
your work is laudable, I was a wireman in the 70s doing summer jobs, then in the late 80s I won a heavily fought over government cable TV franchise for an area called Brighton in South England, with a US company called Cross Country Cable and we sold the franchise for broadband phones and TV to Nynex who then sold it to Cable and Wireless and eventually to Virgin..that was the beginning of the internet but predated it. Thanks for keeping the incredible museum going.....
Fun fact: technically the Hennepin County, MN sirens are Civil Defense sirens and the Ramsey County, MN sirens are for domestic use only. You'd think it'd be the other way, but apparently not. The Hennepin County sirens were able to sync with the previous national EAS test and all other sirens in Minnesota had to be tested at their usual time that day.
Slightly on a tangent, but the title reminded me of when I worked on the BT DDSN contract back in the mid 80s. The core network was based on 5ESS-PRX switches (CCITT signalling) as developed for the Saudi Arabia TEP4 contract. These switches were lacking Centrex features so when Mercury Communications bought DMS100 switches to offer Centrex to the financial businesses in the City of London, BT panicked!! They asked us to provide a switch (located in Baynard House) with Centrex. The only one available was a Bell standard switch used for 'nuclear attack hardening testing' by AT&T USA. This was shipped to the UK and attached to the BT network via 24 to 30 channel PCM converters. In the end it never went live and was used for test/training purposes #goodolddays
This was an interesting video! I'm glad you told us about this stuff. When I was a kid my father repaired all kinds of electrical motors, and he was asked to repair one of the city's sirens. He did the repair, and then he was trying to figure out how to test it. The shop was located in a residential neighborhood so he didn't want to fire it up outside. He did a couple of quick bursts of power to it to make sure it would run at all, and then he wanted to run it up to speed to make sure it was okay. He ended up pointing it down the stairway to the basement, and put a plywood board over the opening, and then firing it up. It was still really loud, but I guess it was quiet enough not to freak out the neighbors too much as no one complained.
i love how much the quality of these videos has gone up since i first subscribed and i love what y'all do at your museum! i really hope i can visit someday!
Wow, two of my nerdy interests shoved into one amazing video? Amazing! Storytime with Claire was lovely, I hope we get more of stuff like that in the future. Very well presented, and the seriousness of the situation was conveyed without being too bleak. This also revealed the link I was missing between Chrysler and Bell for the Chrysler-Bell Victory Siren, the giant V8 engine-powered one shown on the tower. They're absolutely astounding pieces of kit, being one of the few sirens to use forced induction to increase sound output. (On the siren, not the engine!)
This was an absolutely lovely video. Y'all take this topic and make it so easy for anyone to become engrossed in it. The video has a great flow and the production value really shows. I especially like the bit of related history at the end, showing how all these connections can be made. Fantastic way to wrap it up while bringing further interest in other topics. Well done!
I'm an old electronics tech, IT guru, etc. We'd end up having lunch, dinner and well, after passing out discussing circuits and processing, breakfast discussing the same. But then, I'm the guy who, when touring a battleship, got with an old snipe that was working on the engineering issues and went off tour for many hours with said snipe. A joke that came out of that was, "they were ready to begin a snipe hunt". Can't claim originality on that one, just a specific event. And a hint, I'm the guy who can intelligently discuss space cloud effects in vacuum tubes and quantum behavior in semiconductors. And also tear down an engine and transmission in a car and reassemble them working in better condition than before. Dinner? Well, I'm also a reformed chef, that'll leave the recipient comatose for a bit... :P
Y'all deserve an award for how stinkin' AMAZEBALLS your channel is for us phone nerds. Your production values, presentation style and genius-level insight into these marvelous machines is truly magnificent to behold. The stories you are telling now will echo through the eons and help keep all the electrons, and us geeks, happy as we all weave through the wires and switches. And as an audio engineer can I just leave a kudo here to the wizards that capture every whirr, click and hum. I listen to every episode 20-20khz on good studio monitors (with sub!) and revel in every nuance. Tremendous! Thank you 🙏
I adore this channel and this video has become my new favorite here (so far anyway!). Thank you guys so much for all the work you do producing these, I can tell it’s a lot of work and it’s really appreciated.
This is one of your best videos yet. I’m on the other side of the country (Philadelphia) but hope to come visit someday. If you ever start a Patreon I’d love to help support the development of future content!
@@lukejayKind of both, in a fashion. The main trunk circuits from the two core clock distribution exchanges did not distribute the siren activation signals, only confidence / warning signals from either of the two military locations that could initiate the warnings. However, the lines used to distribute the signal from the 250 or so exchanges to so called carrier control points (e.g. police stations or other fortified public service locations) were bidirectional, and tone signals and/or voice messages initiated by humans went back to the local exchange for distribution from there to the local siren / warning distribution network. There's a really excellent description of the system on the ringbell uk site - google ringbell handel warning
@@lukejayI think they were. They’re also was the “HANDEL” radio system. The government distributed these radios that would constantly beep or if an attack was coming they’d make noice and say “Attack warning Red” meaning “your fucked m8” Again the speaking clock lines were used. It’s an amazing system
There are several well maintained Handel devices, I've personally seen them in RAF Holmpton which was used as a monitoring centre (and has an actual Polaris warhead on site!), it's a restored nuclear bunker. I also worked for BT and we had lots of artefacts post cold war.
My old man was an RCAF radar tech on the Pinetree Line, the precursor to the DEW line. It was crazy times and technology evolved very quickly during those times. Also the fire station where I work used to have a Canadien Civil Defense air raid siren behind it, it was an Allertor 125 which was removed when they shut down the system in the 80's.
I remember the AUTOVON red and white cross connect jumpers on the Main Distribution Frames and SSM protectors on the terminations. You didn’t dare touch them.
When I was in the USAF, you could get the base operator to place an Autovon call back home for you at night when there was low traffic. We were sure not to do it too often, which might have raised flags. You had to have after-hours access to a military phone, of course, such as at a MARS station.
As a Boy Scout in the early 1980's, we got a tour of the then-still functioning Autovon facility at Dranesville. It's multiple stories below ground and was designed to blend in with the surrounding residential neighborhood. It remains active today, doubtless with a newer mission and almost certainly no longer allowing Boy Scout troops in.
The catch with the Chrysler Air Raid Siren- Receiving the signal didn't directly activate the siren. It told a guy that he had to go up, start the motor, and manually engage and disengage the clutch to the siren rotor mechanism. One of the top 10 jobs I'd never want, sitting on a roof/tower warning the world that it's ending without being able to hide, yourself!
The air raid siren in Eatonville, WA, was re-purposed in the 90's until the mid to late 00's as a signal to the local volunteer fire department. They ceased using it around the time that Cell phone service became reliable across that area. I remember visiting my grandparents down there one 4th of July and the thing was going off every 45 minutes or so probably because of fireworks related incidents.
My wife grew up in Warrenton, VA and she remembers the town using the air raid sirens to call their volunteer fire department members in the late ‘70’s-early ‘80’s.
@@jimw7ry A lot of municipalities used the same siren for both purposes. At the fire house there was a big controller that actuated the siren. Depending on what signal was sent from the dispatch center to the firehouse over a dedicated copper pair "lease line" it would start the appropriate siren timer, where a synchronous motor turned a bunch of timer cams actuating micro switches and the correct on off timing was sent to the siren contactor.
The Bells & Lights box is a central component of the plot in "Ladybug, Ladybug" - a cold war film available to watch here on TH-cam. It has one of the best endings to a psychological thriller I've ever seen!
This is top-level YT technology content. Thanks so much for telling the story of these devices and the CD method! ...I am old enough to remember the CD in the triangle signs at the local small town bank.....
This series from "Connections Museum" is just amazing! (new subscriber) There are so many wonderful lessons to be learned from the old equipment as they are the basic building blocks of physics, mechanics, electronics and computer programming that we utilize and rely so heavily on today. The Bell engineers did a fantastic job. I think the 359A tube is extremely robust, inexpensive to manufacture and has an very long service life. I think the main limitation is how many ma of current can it sink. Best wishes to the entire museum staff. Many thanks.
I’m a huge civil defense enthusiast. I plan on making a modern version of the “Bell and Lights” system called the Federal Signal “RadAlert”. It’s basically like a fire alarm system but for nuclear fallout when it reaches a city. It’ll also work for nuclear power plant leaks too. The alarm will be a horn strobe similar to a fire alarm but yellow with an amber light.
Thank you for sharing your video. You have an absolutely interesting museum. Communication is something we all take for granted in our current days. The hardware and books that you have bring back memories of growing up in the Cold War era. You are great preservationists and archivists.
You guys are awesome. I can't even imagine how much fun it is to geek out on equipment like this. Thank you for preserving and maintaining this wonderful electronic history! 😎🤘☮️
My grandmother had a large furniture style Hi-Fi stereo and the tuning dial glass had the (CD) printed on two spots. It wasn't until the Internet age I learned what those were for. When I lived in Hawai’i the tsunami warning siren test something I got used to. People can even “adopt” a siren to ensure it is functioning correctly. Then there was the “this is not a drill” day from the EAS. I was working in a resort hotel at the time and I turned on the test TV and seeing how none of the local stations broke away from regular programming I figured it was a false alarm.
In the event of an emergency, all United States television and FM radio stations were required to stop broadcasting. Upon alert, most AM medium-wave stations shut down. The stations that stayed on the air would transmit on either 640 or 1240 kHz. They would transmit for several minutes and then go off the air, and another station would take over on the same frequency in a "round robin" chain. This was to confuse enemy aircraft who might be navigating using radio direction finding. By law, radio sets manufactured between 1953 and 1963 had these two frequencies marked by the triangle-in-circle ("CD Mark") symbol of Civil Defense.[3] Although the system by which the CONELRAD process was initiated (switching the transmitter on and off) was simple, it was prone to numerous false alarms, especially during lightning storms.
MUZAK became an EBS participant by 1986 (see Code of Federal Regs, Title 47, 1986) to supplement the phase out of Bell & Lights inside offices and bldgs. NOAA radio could also relay attack warnings to colleges, schools etc. via NAWAS terminals at NWS offices.
NOAA All-Hazards does that exact thing today; they can warn for everything from Nuclear Attack to Volcanic Eruptions to Avalanche Warnings (yes really; SAME enabled receivers have all those possible warnings and more. They even have one for disease outbreaks which was actually used in some places when Covid hit).
There was a siren right across the street from my grammar school in San Francisco and I remember it going off regularly. I also recall from my service in the U.S. Navy what to do if a nuclear alert went off, as follows: stand up, bend over, put your head between your knees, and kiss your a$$ goodbye ...
Or as I trained my men, "Go to the light, my children, go to the light!". Back when I worked on Pershings, one highly aggressive idiot NCO that entirely failed to advance repeatedly said, "once these missiles go, you are infantry". Growing tired swiftly of that guff, I finally replied, "Sergeant, once those missiles go, we're a bad odor in the air after their counterstrike evaporates us". The brass was nearby and laughed to near incapacity, she was at least speechless, much to the relief at all. My promotion was advanced by a couple of months. Boy, do I enjoy retirement! Now, all I have to worry about is whether or not to trip some asshole with my cane. ;)
Finally, a good back story for those "CD" triangle shaped indicators found on vacuum tube radios from this era. The telephony systems involved are fun to learn about and like all things from early telephony, I remain consistently amazed at what was and could be done without amplifiers. This was a particularly enjoyable video. Thank you. (Man, I gotta visit, and will soon.)
Well, 48 VDC is a common standard in communications. Look at a network router or switch used in a corporate environment, you'll see a plate for a 48 VDC connector. Some datacenters actually have 48 VDC buses to support network equipment today. DC doesn't travel well, Edison's failure, Tesla and others got it right that AC travels well. There is minimal travel in a datacenter, so DC makes sense, uses less circuitry and requires less regulation, due to its already regulated condition.
@@spvillano48V DC "phantom power" is also used as a power standard in audio recording, specifically microphones, as a holdover from the telecom industry as well.
Claire and Sarah are adorable ❤ and cool , I love learning about old Civil Defence warining systems, alarms and communications technology, since I was a little kid I've always been fascinated by how this equipment works, I've always loved seeing these old systems being demonstrated how they work. Thank you so much for making these videos they are awsome I look forward to seeing more of these Great videos thanks again 🩷💜💙
I am very impressed at the incredible detail you all provided in this documentary. I have never seen the CD/CARW system described in any BSTJ journal publications. Combine that with your breif overview of the DEW line and White Alice, along with AUTOVON is great. Now, any chance of doing a video on Project offices and hardened L systems in the 60s for CoG?
You passion for this nerdy stuff is so infectious. If I weren't already a telecom nerd (have been since the early 90s), I would be after watching these videos.
Fascinating video. I'm a geezer so grew up with air raid warning siren tests but I had no idea of the technology used behind the scene. As soon as Sarah started describing the tubes used to the illuminated notification box I knew they were repurposed selective 4-party calling. I never had the thrill of being on a 4-party phone line but 2-party phone lines were still pretty common into the 1970s and marketed at a lower cost. A far cry from today where everyone has their personal phone number.
Thanks for sharing your technical knowledge on how the bell system worked with the CD system. As a kid I remember the "duck and cover" drills a school.
I started as a dispatcher for a county sheriff in 1977. Our center didn't have such a device, nor did the three municipal centers. By then, alerts were sent by teletype and sirens were activated via a different device.
So cool you could leverage the retirees memorabelia from their time in Alaska doing the comms work there. Always valuable, and absolutely needed to prevent the details from getting lost. This was a great video, and makes me think of the old Dr. Seuss title, "Oh the places you'll go" from CARWash to White Alice, to the DEWline, to Long Lines and Telstar.
This was great and brought back memories. I went to that school, John B. Allen elementary in the 3rd grade, probably around 1970(?) and I remember that air raid siren sounding every week, I think it was Wednesday at noon? It was loud!
Oh my, microwave relay links. A brief anecdote about that lovely White Alice technology: back in the day (in this case, the 1980s day) my employer had a leased data line from AT&T between northern California and Arizona, and mysteriously the line would fail fairly regularly in the summer. The story we eventually received from the nice people at AT&T Long Lines was that the culprit was smog-induced multipath distortion on the microwave links passing through Los Angeles. It is lovely to see that those clever folks at Western Electric repurposed 4-party polarity signalling to light those four lamps (without actually requiring Extra Lamps, super bonus moment, we'll just use these Light Emitting Relays we are using as the lamps). Thanks so much for all you do (and all you film)--as you can tell, it delights me.
I remember back in 1978 working with GTE labs in San Carlos, California the development of isolinear chip designs to replace the aging relay switching circuits.
Fun fact about autovon and the later Defense Switched Network: it also extends to field phones! With a touch tone dialpad accessory, a hand crank field phone could be converted into a 16-button DTMF set with appropriately labeled FO, F, I, and P keys.
I'm curious why CARW used a separate ringing generator that was only powered infrequently during activation, as using a relay switched cycle from the main office ring generator would have improved reliability by using a constant use system meaning faults would be quickly identified/fixed. (The British Telecom equivalent of this system called HANDEL used the Speaking Clock circuit to ensure quick fault detection, in a similar way.)
It could have been a consideration of load. If there were more than 100 stations to ring simultaneously, that could put a significant load on the main ringing generator, which might already be overloaded if there was a real emergency. There is an option to use the main ringing generator in the schematic. It’s up to the telephone company how they actually want to wire it. Faults are located by all of the dials and all of the bell and lights stations being in one large circuit. If that circuit is broken at any time, an alarm will sound.
@@ConnectionsMuseum Thanks so much for the info! It's greatly appreciated as always. I'm so grateful for all the time and effort that all of you put in for systems such as CARW, which could easily get somewhat lost given their relative lack of public discussion during their service life. Actually, I'm grateful for everything that you all do, always. Yes, I can absolutely see the point about not overloading the main ringing generator that may well already be overloaded under conditions where the system would actually be needed. That's an extremely good point. I hadn't thought of that, and actually I should have done, because the British HANDEL system suffered from a similar problem but in a different way. Whilst it was a voice announcement system using a carrier tone to activate the receivers, as it used the local exchange speaking clock circuit to operate (injected before the line amplifiers from the clock announcer so as to use the same office equipment) this meant each receiver station needed a local battery and/or mains power source for local amplification due to the line attenuation caused by the alert stations when they went off hook on the same shared circuit in response to the carrier. Obviously, the line amplifiers for the speaking clock were never intended for that many subscriber lines being connected under normal conditions. In comparison, the American CARW system has the huge advantage that it's entirely powered by the line current and avoids the huge wall mounted receiver/transmitter sets that HANDEL needed at all relevant police, fire, military and government locations. I do love the simplicity of the user sets for CARW in comparison and also that it shows a decisive alert state rather than a generic alarm followed by a live spoken transmission that had to be specifically listened to.
I vaguely remember growing up in L.A. the air raid sirens going off once a month as a test. I think was either the last Monday or last Friday of the month at 10:00 am. It was about the same time at my elementary school that we were out on the playground for recess. We never paid attention to them, other than hear the siren go off for a few minutes each month. No bombs were ever coming to be dropped on us, so school was never cancelled.
Very informative and entertaining video. As an Australian it is really intriguing to know there was this level of public warning system. I dont think we had anything apart from radio warnings. Will definetly visit your museum when i hopefully go to USA next year.
I've watched a few videos from this channel over the years about telephone equipment when I was listening to the Evan Doorbell tapes... But the kind of information placed in historical context, and presentation in THIS video is awesome and EXACTLY up my alley, well done! Also, are you sure there aren't five lights?
About 14 years ago, I did some work with the Upgraded Early Warning Radar network, which is what replaced the DEW Line. Of course, its purpose now is not just to provide warning, but to direct missile defense systems. Hopefully, the day will come when we can make that system big enough that a preemptive first strike will no longer be possible.
Sarah and Claire loved this video. I’m into the Civil Defense system enjoyed the explanation of how the telephone company AT&T was involved. The dial and the lights are so cool. I have to get a shirt! ❤
Fun fact about that air raid siren you were standing in front of, it’s made by Chrysler and sports a Chrysler V-8 331-CID Hemi Engine And the siren has a Decibel Output of 138dB at 100 feet, it’s definitely one of the most distinct sounding sirens so when you hear it go off you know exactly what siren it is by the tone of the wail!
Would love to acquire one of these units! A true classic and a real sound blaster! The newer Federal Signal and Whalen voice over sirens are nice as well!
Chrysler had a restored one at their museum before it closed up in 2016
@@erichite4871 damn 😢 😞
Was going to mention this, but here you are,.
(Yes, there are siren and klaxon geeks too!)
rumor has it it could have lit any nearby dry leaves on fire... I dont' believe it, but, 138dba at that frequency range is nothing to laugh at
i already loved this channel but the production quality has really gone up recently and I’m here for it!
1. Wow this was exactly the amount of information I wanted when I clicked the video
2. You’re on the top of my list for if I ever visit Seattle yet somehow I wasn’t subscribed to your channel‽
So glad you enjoyed it! We'd love to have you visit sometime; You have at least a few fans yourself here at the museum, myself included. -Claire
@@ConnectionsMuseum 💖
The Museum is terrific! Definitely visit!
The bounciest man on the internet, Matt Gray!
"I am so proud I only got shocked twice"🤣 Got to love Sarah she has a way with words. Seriously this is one of the best technical channels on TH-cam
There's nothing worse than getting your hand shocked on connections on a wirewrap block on a frame and jerking it forcefully driving the back of your hand into the block next to it and getting shocked again.
It would have only happened once with the equipment I worked with High voltage DC at enough current to set you on fire. One transmitter used 7,000VDC at over 5 A for normal operation,. The filaments in the final tubes were 1.5V @ 1000A each so that was 3KW f ac current per tube. One would set you on fire, the other would melt any tools that got in the way.
Bonus points for doing the "There are four lights" routine from Star Trek TNG. (Though it must be considered obligatory when actually talking about four lights!) 😁
Glad the joke came across. Was concerned that people might not get it :)
Just don't be the one wearing the red shirt... 🙄
Would never have noticed the reference without your comment
1984
@@WR3ND Yes, it's from the Star Trek Next Generation episode "Chain of Command" part 2, and it is indeed a reference to 1984 by George Orwell.
I went to school at Arizona State University in the late '80's. Every Saturday at noon, the air raid siren on the hill to the north of campus went off during its weekly test. Us dorm dorks referred to it as the "hangover check."
This siren had a rotating horn assembly to extend the reach of audibility. As the siren went through the test, you could hear the sound volume (the actual volume, not warbling) change as the rotation came up to speed, became steady, then slowed back down to a stop. On particularly bad Saturdays, it would come to rest with the business end pointing straight at campus, so you got to listen to the siren at full volume until the siren itself finally spun back down.
Great video. Thanks for the fantastic history lesson.
The Defense Switch Network, the successor to AUTOVON, is still very much alive and well today! We even still have the same 4 priority levels (Priority, Immediate, Flash, Flash Override) that you can use on DSN calls.
Reminds me of the CBS Net Alert in a way. 0-9 with the “Big One” being NATIONAL EMERGENCY.
Which go through the red switch network. Digitized in the '90's, rendering the old AUTOVON network obsolete.
I remember our staff meetings, initially IA getting to go after red switch briefed on their status, but after some rather high profile events, IA got to go before red switch had nothing to report.
We did have red switch go down twice at one installation and well, due to that installation's purpose, theater wide.
Once, due to a generator failure, the other, a transformer fire, both triggering failover to the building UPS that was inoperable until the generators could come online. A longstanding issue of a room full of defunct batteries was swiftly addressed after the second time the general's phone stopped working...
I still remember siren codes. Warbling wail, a warning. Pulsating, strike incoming soon. Continuous, strike imminent.
Goes back to warble, all clear. 3 - 5 minutes duration.
Adapted in many areas to warble a warning, continuous typically being a tornado is about to relocate your furniture.
But, all derived from the military system, which had a few additional tone codes, before we all ended up with computing devices attached to our gonads. ;)
There was a "Bells & Lights" box in the office of my elementary school, just outside the principal's office - where I often sat waiting to "discuss my attitude problem". I was fascinated by every part of it down to the _Private Line_ sticker on the connector block.
I had much the same experience! I remember one fine day when i was sitting there and it rang, quite loudly. I asked the office staff what that thing was but they either didn't know or didn't want to engage with the kid in detention, but they declined to explain. I guess I've been waiting for this video for over 50 years! Thanks to Sarah et al for posting it. I also have memories of the air raid sirens wailing their monthly test run. A kind of eerie feeling as the waves of sound from multiple sirens cascaded over the city.
I remember drills in elementary school.
Crouch under your desk, face away from the windows and put your head between your knees.
We used to joke .. 'and kiss your ass goodbye'
@@jimurrata6785no memory of those, they ended shortly before I went to school. But then, I was born a week after Tzar Bomba was detonated.
But, after starting a lengthy military career, in nukes initially, I've a different mode of address to a nuclear warning. "Go to the light, my children!"
And I live now at pretty much ground zero, a state capital, a couple of blocks from the governor's residence, in a region ringed with military supply depots and communications nodes. A hint for the curious, I miss a major navigational landmark that's now gone for a hand span of years, the plume from Three Mile Island.
@@spvillano Steam from a cooling tower is pretty empherial, for a landmark.
I remember the meltdown. People where I was (NYC) were concerned if the containment burst.
Thankfully we didn't have a situation like in Ukraine.
@@jimurrata6785indeed! I was in Delaware County, just south of Philly when it melted down.
Hollywood reliably informed us a week before that Pennsylvania would be uninhabitable. So, per Hollywood, I guess that I'm dead or something. ;)
Chernobyl, well, that was quite the series of errors, from construction with an inflammable roof (specified to not be so in their plans) onward. Yeah, one of their specifications was for a non-flammable roof. So, corruption ensued, flammable roof installed.
Sarah is such a great presenter. You guys are making kick ass videos one after another. The museum is totally on my bucket list thanks to your videos.
Went to High School in the mid 1960s in Kenai , Alaska where there were White Alice antennas locted 25 miles north of town. I had a mobile CB radio in my VW bug and found that finding the sweet spot in front of the White Alice antenna allowed my to converse with other CB operators in Japan when " Skip Signal conditions were present.
My father worked on the White Allice site outside of Kotzebue, AK. I've visited the site, which I believe you pictured. (As well as the "Kotzebue National Forrest" :) He was also one of the lead engineers for RCA / Alascom that designed the microwave and satellite communications systems to bring modern communication to remote Alaska villages.
All of this was an immense undertaking to build. It kept my father flying around Alaska in his Cessna for the better part of 15 years. Thank you for bringing the history of this system to everyone. It brought back warm memories seeing these photos again.
And as Picard would say, "Well done."
a cool fact about that big siren you opened the video in front of. it was the loudest siren ever built, powered by a Chrysler Hemi V8.
Many places in “tornado alley” still maintain similar systems to this day. Here in Indianapolis they go off every Friday around 11 a.m. Instead of nuclear missiles, they warn people of dangerous weather like, as the name of the region may suggest, tornados.
I live in Saint Cloud Minnesota and they have Federal Signal 2001 sirens they test once a month and the National Weather Service tests the Weather Radio alert system every Thursday at 1 pm.
We have sirens where I live, but they don't (audibly) test them. The only times I've heard them sound is when a (very rare) tornado is on the ground.
they just used them for the severe warning a week ago I think it was too.
Yah, here in Minnesota, they audibly test the "tornado sirens" at 1 PM on the first Wednesday of every month.
Also, the first full week of April is Severe Weather Awareness Week here. And on Thursday that week, the sirens sound statewide at 1:45 PM and 6:45 PM for the statewide tornado drill.
I've been around telecom my whole life - my dad worked for Michigan Bell for 30 years - and I've always been a Civil Defense buff. This video is a double whammy for me!
I'm just think how that little maneuver @13:17 could have been enhanced with a properly timed slide whistle. Another fantastic educational video. Thanks and keep it up!
your work is laudable, I was a wireman in the 70s doing summer jobs, then in the late 80s I won a heavily fought over government cable TV franchise for an area called Brighton in South England, with a US company called Cross Country Cable and we sold the franchise for broadband phones and TV to Nynex who then sold it to Cable and Wireless and eventually to Virgin..that was the beginning of the internet but predated it. Thanks for keeping the incredible museum going.....
Fun fact: technically the Hennepin County, MN sirens are Civil Defense sirens and the Ramsey County, MN sirens are for domestic use only. You'd think it'd be the other way, but apparently not. The Hennepin County sirens were able to sync with the previous national EAS test and all other sirens in Minnesota had to be tested at their usual time that day.
I wish I didn't have to cross an entire ocean to come visit this museum, it looks amazing. One day.....
Wow! Beautiful video!
❤️🧡💛💚🩵💙
Slightly on a tangent, but the title reminded me of when I worked on the BT DDSN contract back in the mid 80s. The core network was based on 5ESS-PRX switches (CCITT signalling) as developed for the Saudi Arabia TEP4 contract. These switches were lacking Centrex features so when Mercury Communications bought DMS100 switches to offer Centrex to the financial businesses in the City of London, BT panicked!! They asked us to provide a switch (located in Baynard House) with Centrex. The only one available was a Bell standard switch used for 'nuclear attack hardening testing' by AT&T USA. This was shipped to the UK and attached to the BT network via 24 to 30 channel PCM converters. In the end it never went live and was used for test/training purposes #goodolddays
This was an interesting video! I'm glad you told us about this stuff. When I was a kid my father repaired all kinds of electrical motors, and he was asked to repair one of the city's sirens. He did the repair, and then he was trying to figure out how to test it. The shop was located in a residential neighborhood so he didn't want to fire it up outside. He did a couple of quick bursts of power to it to make sure it would run at all, and then he wanted to run it up to speed to make sure it was okay. He ended up pointing it down the stairway to the basement, and put a plywood board over the opening, and then firing it up. It was still really loud, but I guess it was quiet enough not to freak out the neighbors too much as no one complained.
i love how much the quality of these videos has gone up since i first subscribed and i love what y'all do at your museum! i really hope i can visit someday!
Wow, two of my nerdy interests shoved into one amazing video? Amazing!
Storytime with Claire was lovely, I hope we get more of stuff like that in the future. Very well presented, and the seriousness of the situation was conveyed without being too bleak.
This also revealed the link I was missing between Chrysler and Bell for the Chrysler-Bell Victory Siren, the giant V8 engine-powered one shown on the tower. They're absolutely astounding pieces of kit, being one of the few sirens to use forced induction to increase sound output. (On the siren, not the engine!)
This was an absolutely lovely video. Y'all take this topic and make it so easy for anyone to become engrossed in it. The video has a great flow and the production value really shows. I especially like the bit of related history at the end, showing how all these connections can be made. Fantastic way to wrap it up while bringing further interest in other topics. Well done!
Thank you so much!
I'm an old electronics tech, IT guru, etc. We'd end up having lunch, dinner and well, after passing out discussing circuits and processing, breakfast discussing the same.
But then, I'm the guy who, when touring a battleship, got with an old snipe that was working on the engineering issues and went off tour for many hours with said snipe. A joke that came out of that was, "they were ready to begin a snipe hunt". Can't claim originality on that one, just a specific event.
And a hint, I'm the guy who can intelligently discuss space cloud effects in vacuum tubes and quantum behavior in semiconductors. And also tear down an engine and transmission in a car and reassemble them working in better condition than before.
Dinner? Well, I'm also a reformed chef, that'll leave the recipient comatose for a bit... :P
NAWAS is still used, I just hooked one up at a new 911 center. They still use the red phones, but copper to fiber at the demarc point.
Are you referring to NAWAS?
@@Robinzano yes sorry typo
That's one of the best videos y'all have made yet! Fascinating and informative.
I definitely have a civil defense addiction, I’ve watched this video at least 15 times and I still can’t get enough of it. Ok I’m starting it again
The Connections Museum is an amazing wealth of knowledge and technical history!! And your videos just keep getting better and better!!!!
👏👏👏
Thanks so much!
Y'all deserve an award for how stinkin' AMAZEBALLS your channel is for us phone nerds. Your production values, presentation style and genius-level insight into these marvelous machines is truly magnificent to behold.
The stories you are telling now will echo through the eons and help keep all the electrons, and us geeks, happy as we all weave through the wires and switches.
And as an audio engineer can I just leave a kudo here to the wizards that capture every whirr, click and hum. I listen to every episode 20-20khz on good studio monitors (with sub!) and revel in every nuance. Tremendous!
Thank you 🙏
I adore this channel and this video has become my new favorite here (so far anyway!). Thank you guys so much for all the work you do producing these, I can tell it’s a lot of work and it’s really appreciated.
My father worked as a foreman for Bell during construction of both the White Alice and the DEW Line. Thank you for bring back a lot of great memories.
Love this. Love the tech, the descriptions, the production. Love your hair and the sweater too!! Thanks for this and all your fascinating videos!!
The amount of context provided is outstanding.
This is one of your best videos yet. I’m on the other side of the country (Philadelphia) but hope to come visit someday. If you ever start a Patreon I’d love to help support the development of future content!
In the UK, the "Speaking Clock" lines were used - every telephone exchange had a feed from a central location.
Very clever to repurpose the speaking clock lines!
Were they used to sound air raid sirens, or to give important information?
Clever either way!
@@lukejayKind of both, in a fashion.
The main trunk circuits from the two core clock distribution exchanges did not distribute the siren activation signals, only confidence / warning signals from either of the two military locations that could initiate the warnings.
However, the lines used to distribute the signal from the 250 or so exchanges to so called carrier control points (e.g. police stations or other fortified public service locations) were bidirectional, and tone signals and/or voice messages initiated by humans went back to the local exchange for distribution from there to the local siren / warning distribution network.
There's a really excellent description of the system on the ringbell uk site - google ringbell handel warning
@@lukejayI think they were. They’re also was the “HANDEL” radio system. The government distributed these radios that would constantly beep or if an attack was coming they’d make noice and say “Attack warning Red” meaning “your fucked m8”
Again the speaking clock lines were used. It’s an amazing system
There are several well maintained Handel devices, I've personally seen them in RAF Holmpton which was used as a monitoring centre (and has an actual Polaris warhead on site!), it's a restored nuclear bunker. I also worked for BT and we had lots of artefacts post cold war.
My old man was an RCAF radar tech on the Pinetree Line, the precursor to the DEW line. It was crazy times and technology evolved very quickly during those times. Also the fire station where I work used to have a Canadien Civil Defense air raid siren behind it, it was an Allertor 125 which was removed when they shut down the system in the 80's.
I remember the AUTOVON red and white cross connect jumpers on the Main Distribution Frames and SSM protectors on the terminations. You didn’t dare touch them.
I was wondering how would one know not to connect a buttset to this type of line
Tell us idiots more!
When I was in the USAF, you could get the base operator to place an Autovon call back home for you at night when there was low traffic. We were sure not to do it too often, which might have raised flags. You had to have after-hours access to a military phone, of course, such as at a MARS station.
As a Boy Scout in the early 1980's, we got a tour of the then-still functioning Autovon facility at Dranesville. It's multiple stories below ground and was designed to blend in with the surrounding residential neighborhood. It remains active today, doubtless with a newer mission and almost certainly no longer allowing Boy Scout troops in.
I could spend day's at your museum and never run out of exciting things to learn about. I hope I can visit someday ❤
The catch with the Chrysler Air Raid Siren- Receiving the signal didn't directly activate the siren. It told a guy that he had to go up, start the motor, and manually engage and disengage the clutch to the siren rotor mechanism. One of the top 10 jobs I'd never want, sitting on a roof/tower warning the world that it's ending without being able to hide, yourself!
The quality and information in these videos just keeps getting better and better!!! Serious respect to everyone for their hard work over there!
The air raid siren in Eatonville, WA, was re-purposed in the 90's until the mid to late 00's as a signal to the local volunteer fire department. They ceased using it around the time that Cell phone service became reliable across that area.
I remember visiting my grandparents down there one 4th of July and the thing was going off every 45 minutes or so probably because of fireworks related incidents.
My county continues to use sirens for fire calls, and because of that sirens are completely disregarded except near the nuclear power plant.
My wife grew up in Warrenton, VA and she remembers the town using the air raid sirens to call their volunteer fire department members in the late ‘70’s-early ‘80’s.
@@lizzylightning6224 No... It was a siren at the fire station set off remotely by the dispatch center. It was NOT an air-raid siren.
@@jimw7ry A lot of municipalities used the same siren for both purposes. At the fire house there was a big controller that actuated the siren. Depending on what signal was sent from the dispatch center to the firehouse over a dedicated copper pair "lease line" it would start the appropriate siren timer, where a synchronous motor turned a bunch of timer cams actuating micro switches and the correct on off timing was sent to the siren contactor.
Thanks for the excellently narrated and produced video. You did a great job of tying many Cold War loose ends together.
The Bells & Lights box is a central component of the plot in "Ladybug, Ladybug" - a cold war film available to watch here on TH-cam. It has one of the best endings to a psychological thriller I've ever seen!
Almost spooky.
This is top-level YT technology content. Thanks so much for telling the story of these devices and the CD method! ...I am old enough to remember the CD in the triangle signs at the local small town bank.....
There are a few buildings around here that still have the old Fallout Shelter signs.
This series from "Connections Museum" is just amazing! (new subscriber) There are so many wonderful lessons to be learned from the old equipment as they are the basic building blocks of physics, mechanics, electronics and computer programming that we utilize and rely so heavily on today. The Bell engineers did a fantastic job. I think the 359A tube is extremely robust, inexpensive to manufacture and has an very long service life. I think the main limitation is how many ma of current can it sink.
Best wishes to the entire museum staff. Many thanks.
I’m a huge civil defense enthusiast. I plan on making a modern version of the “Bell and Lights” system called the Federal Signal “RadAlert”. It’s basically like a fire alarm system but for nuclear fallout when it reaches a city. It’ll also work for nuclear power plant leaks too. The alarm will be a horn strobe similar to a fire alarm but yellow with an amber light.
Thank you for sharing your video. You have an absolutely interesting museum. Communication is something we all take for granted in our current days.
The hardware and books that you have bring back memories of growing up in the Cold War era.
You are great preservationists and archivists.
You guys are awesome. I can't even imagine how much fun it is to geek out on equipment like this. Thank you for preserving and maintaining this wonderful electronic history! 😎🤘☮️
My grandmother had a large furniture style Hi-Fi stereo and the tuning dial glass had the (CD) printed on two spots. It wasn't until the Internet age I learned what those were for.
When I lived in Hawai’i the tsunami warning siren test something I got used to. People can even “adopt” a siren to ensure it is functioning correctly. Then there was the “this is not a drill” day from the EAS. I was working in a resort hotel at the time and I turned on the test TV and seeing how none of the local stations broke away from regular programming I figured it was a false alarm.
In the event of an emergency, all United States television and FM radio stations were required to stop broadcasting. Upon alert, most AM medium-wave stations shut down. The stations that stayed on the air would transmit on either 640 or 1240 kHz. They would transmit for several minutes and then go off the air, and another station would take over on the same frequency in a "round robin" chain. This was to confuse enemy aircraft who might be navigating using radio direction finding. By law, radio sets manufactured between 1953 and 1963 had these two frequencies marked by the triangle-in-circle ("CD Mark") symbol of Civil Defense.[3]
Although the system by which the CONELRAD process was initiated (switching the transmitter on and off) was simple, it was prone to numerous false alarms, especially during lightning storms.
Outstanding! Great job, really! Thank you for bringing it all back.
MUZAK became an EBS participant by 1986 (see Code of Federal Regs, Title 47, 1986) to supplement the phase out of Bell & Lights inside offices and bldgs. NOAA radio could also relay attack warnings to colleges, schools etc. via NAWAS terminals at NWS offices.
NOAA All-Hazards does that exact thing today; they can warn for everything from Nuclear Attack to Volcanic Eruptions to Avalanche Warnings (yes really; SAME enabled receivers have all those possible warnings and more. They even have one for disease outbreaks which was actually used in some places when Covid hit).
There was a siren right across the street from my grammar school in San Francisco and I remember it going off regularly. I also recall from my service in the U.S. Navy what to do if a nuclear alert went off, as follows: stand up, bend over, put your head between your knees, and kiss your a$$ goodbye ...
Or as I trained my men, "Go to the light, my children, go to the light!".
Back when I worked on Pershings, one highly aggressive idiot NCO that entirely failed to advance repeatedly said, "once these missiles go, you are infantry".
Growing tired swiftly of that guff, I finally replied, "Sergeant, once those missiles go, we're a bad odor in the air after their counterstrike evaporates us".
The brass was nearby and laughed to near incapacity, she was at least speechless, much to the relief at all. My promotion was advanced by a couple of months.
Boy, do I enjoy retirement! Now, all I have to worry about is whether or not to trip some asshole with my cane. ;)
Oh... My Goodness 😮
Finally, a good back story for those "CD" triangle shaped indicators found on vacuum tube radios from this era.
The telephony systems involved are fun to learn about and like all things from early telephony, I remain consistently amazed at what was and could be done without amplifiers. This was a particularly enjoyable video. Thank you. (Man, I gotta visit, and will soon.)
Thanks for adding actual captions for the Deaf
You’re welcome. We try our best to do so for every video but sometimes we miss one or two.
Incredible video, I learned a lot. Thanks for all the hard work putting this together. Now I want to make it up to Seattle to check out the museum
This is incredibly interesting! I really love how far relay logic can go if someone puts the time into designing the system.
Using the power supply for a piece of VoIP equipment to power up your vintage frame seems appropriate.
Well, 48 VDC is a common standard in communications.
Look at a network router or switch used in a corporate environment, you'll see a plate for a 48 VDC connector. Some datacenters actually have 48 VDC buses to support network equipment today.
DC doesn't travel well, Edison's failure, Tesla and others got it right that AC travels well. There is minimal travel in a datacenter, so DC makes sense, uses less circuitry and requires less regulation, due to its already regulated condition.
@@spvillano48V DC "phantom power" is also used as a power standard in audio recording, specifically microphones, as a holdover from the telecom industry as well.
Thank you for this great video! It is so cool to see obscure telecom hardware being brought back to life!
You’re amazing. Fantastic to see everything in working order. Love your work ❤
Fantastic video! This is the first I ever heard of CARWash, and I'm excited that you have Autovon equipment in the museum. Very informative!
Amazing video Team!
Awesome work all around! Thanks for the insight!
Claire and Sarah are adorable ❤ and cool , I love learning about old Civil Defence warining systems, alarms and communications technology, since I was a little kid I've always been fascinated by how this equipment works, I've always loved seeing these old systems being demonstrated how they work. Thank you so much for making these videos they are awsome I look forward to seeing more of these Great videos thanks again 🩷💜💙
Your such brilliant story teller’s. Very interesting video. I like the way the telephone company used their existing tech in a different way.
What an outstanding, well-researched and informative video! Bravo.
I am very impressed at the incredible detail you all provided in this documentary. I have never seen the CD/CARW system described in any BSTJ journal publications. Combine that with your breif overview of the DEW line and White Alice, along with AUTOVON is great. Now, any chance of doing a video on Project offices and hardened L systems in the 60s for CoG?
This is such a cool part of history, thank you for sharing!
You passion for this nerdy stuff is so infectious. If I weren't already a telecom nerd (have been since the early 90s), I would be after watching these videos.
Fascinating video. I'm a geezer so grew up with air raid warning siren tests but I had no idea of the technology used behind the scene. As soon as Sarah started describing the tubes used to the illuminated notification box I knew they were repurposed selective 4-party calling. I never had the thrill of being on a 4-party phone line but 2-party phone lines were still pretty common into the 1970s and marketed at a lower cost. A far cry from today where everyone has their personal phone number.
i love all of you. Thanks for telling all of these stories!!
as a 68 year old man, I so remember the noon on Wednesday tests weekly test. still have PDSD over that!
Thanks for sharing your technical knowledge on how the bell system worked with the CD system. As a kid I remember the "duck and cover" drills a school.
I started as a dispatcher for a county sheriff in 1977. Our center didn't have such a device, nor did the three municipal centers. By then, alerts were sent by teletype and sirens were activated via a different device.
Well documented! Thanks for producing this.
Glad you enjoyed it!
So cool you could leverage the retirees memorabelia from their time in Alaska doing the comms work there. Always valuable, and absolutely needed to prevent the details from getting lost. This was a great video, and makes me think of the old Dr. Seuss title, "Oh the places you'll go" from CARWash to White Alice, to the DEWline, to Long Lines and Telstar.
This is fascinating to me. Thanks for doing such a concise deep dive on the carwash!
A fascinating video as always! As a kid, I remember that distinctive wail of the civil defense sirens - it still kind of freaks me out today!
Very interesting! Thanks again for another great video. I grew up just toward the end of the Cold War. It was exciting times.
This was great and brought back memories. I went to that school, John B. Allen elementary in the 3rd grade, probably around 1970(?) and I remember that air raid siren sounding every week, I think it was Wednesday at noon? It was loud!
I bet Fran Blanche would be proud add this to her FranLab
Great video and thank you so much to Claire for the digitisation efforts on Internet Archive
Love the camera angle in between rack equipment. Thanks for the data download!
Oh my, microwave relay links. A brief anecdote about that lovely White Alice technology: back in the day (in this case, the 1980s day) my employer had a leased data line from AT&T between northern California and Arizona, and mysteriously the line would fail fairly regularly in the summer. The story we eventually received from the nice people at AT&T Long Lines was that the culprit was smog-induced multipath distortion on the microwave links passing through Los Angeles. It is lovely to see that those clever folks at Western Electric repurposed 4-party polarity signalling to light those four lamps (without actually requiring Extra Lamps, super bonus moment, we'll just use these Light Emitting Relays we are using as the lamps). Thanks so much for all you do (and all you film)--as you can tell, it delights me.
Your stuff is always detailed and fascinating thank you😊😊
I remember back in 1978 working with GTE labs in San Carlos, California the development of isolinear chip designs to replace the aging relay switching circuits.
that one you are showing in Seattle looks like a victory air raid siren built by the Chrysler Automotive Company powered by a V8 Hemi Engine
Fun fact about autovon and the later Defense Switched Network: it also extends to field phones! With a touch tone dialpad accessory, a hand crank field phone could be converted into a 16-button DTMF set with appropriately labeled FO, F, I, and P keys.
I'm curious why CARW used a separate ringing generator that was only powered infrequently during activation, as using a relay switched cycle from the main office ring generator would have improved reliability by using a constant use system meaning faults would be quickly identified/fixed. (The British Telecom equivalent of this system called HANDEL used the Speaking Clock circuit to ensure quick fault detection, in a similar way.)
It could have been a consideration of load. If there were more than 100 stations to ring simultaneously, that could put a significant load on the main ringing generator, which might already be overloaded if there was a real emergency.
There is an option to use the main ringing generator in the schematic. It’s up to the telephone company how they actually want to wire it.
Faults are located by all of the dials and all of the bell and lights stations being in one large circuit. If that circuit is broken at any time, an alarm will sound.
@@ConnectionsMuseum Thanks so much for the info! It's greatly appreciated as always. I'm so grateful for all the time and effort that all of you put in for systems such as CARW, which could easily get somewhat lost given their relative lack of public discussion during their service life. Actually, I'm grateful for everything that you all do, always.
Yes, I can absolutely see the point about not overloading the main ringing generator that may well already be overloaded under conditions where the system would actually be needed. That's an extremely good point.
I hadn't thought of that, and actually I should have done, because the British HANDEL system suffered from a similar problem but in a different way. Whilst it was a voice announcement system using a carrier tone to activate the receivers, as it used the local exchange speaking clock circuit to operate (injected before the line amplifiers from the clock announcer so as to use the same office equipment) this meant each receiver station needed a local battery and/or mains power source for local amplification due to the line attenuation caused by the alert stations when they went off hook on the same shared circuit in response to the carrier. Obviously, the line amplifiers for the speaking clock were never intended for that many subscriber lines being connected under normal conditions.
In comparison, the American CARW system has the huge advantage that it's entirely powered by the line current and avoids the huge wall mounted receiver/transmitter sets that HANDEL needed at all relevant police, fire, military and government locations. I do love the simplicity of the user sets for CARW in comparison and also that it shows a decisive alert state rather than a generic alarm followed by a live spoken transmission that had to be specifically listened to.
I vaguely remember growing up in L.A. the air raid sirens going off once a month as a test. I think was either the last Monday or last Friday of the month at 10:00 am. It was about the same time at my elementary school that we were out on the playground for recess. We never paid attention to them, other than hear the siren go off for a few minutes each month. No bombs were ever coming to be dropped on us, so school was never cancelled.
always a pleasure watching this! congrats, team!
Very informative and entertaining video. As an Australian it is really intriguing to know there was this level of public warning system. I dont think we had anything apart from radio warnings.
Will definetly visit your museum when i hopefully go to USA next year.
I've watched a few videos from this channel over the years about telephone equipment when I was listening to the Evan Doorbell tapes... But the kind of information placed in historical context, and presentation in THIS video is awesome and EXACTLY up my alley, well done!
Also, are you sure there aren't five lights?
What's the map at 22:14 specifically from? Searched around and got stuff similar, but not exact. Thanks.
About 14 years ago, I did some work with the Upgraded Early Warning Radar network, which is what replaced the DEW Line. Of course, its purpose now is not just to provide warning, but to direct missile defense systems. Hopefully, the day will come when we can make that system big enough that a preemptive first strike will no longer be possible.
I recommend the Connections Museum. Very interesting place.
Loving the high concept production here.
loves the history in this one :D
Sarah and Claire loved this video. I’m into the Civil Defense system enjoyed the explanation of how the telephone company AT&T was involved. The dial and the lights are so cool. I have to get a shirt! ❤
I never knew such a thing existed. Thanks for doing a video on it.