I imagine some of those racks had multiplexers in them. It's amazing you were able to power up the building after 25+ years. It is a testament to the quality of AT&T manufacturing that nothing shorted, blew-up, or caught fire. I was waiting for the magic smoke. 😁
Bro, go to the communications museum in Seattle Washington. I’m from Wisconsin and I’ve flown out there 6 times already this year to see their stuff. They have 2 warehouse sized floors of working telephone switching equipment from Stroger switches, step-by-step switches, cross bar switches, microwave carriers, you name it. It’s only open on Sundays though from 10 AM to 4 PM. There is no entry fee but leave a donation is encouraged.
They also have a ton of engineers our age there who work alongside with all Bell System engineers. All the equipment can be played with and you can ask all the questions you want. It’s awesome. Plan your next trip there
TH-cam suggested this probably because I'm a technology geek. Thanks for this video. It shows how well prepared our country always tries to be to ensure we have highly reliable government and military communications if things were to get serious. Excellent presentation.
The nuclear continuity plan is to destroy all other countries entirely to save what they can of the US. We're all dead once there's no food, no low-cost Chinese manufactering which is essential now, no ships crossing the ocean. Remember COVID and supply chain problems? You ain't seen nothing. All outbound missiles are pretargetted there are no options for surviving nuclear war other than to hope we hit them before they hit us. They have us convinced that they're going to protect us. With what? I don't want to survive such an eventl Nuclear winter, no energy, no water, no food. Good times.
The "Microwave module" is actually a Nokia router with different module options (Verizon uses those Nokias). The top slots looks like fiber optic interfaces, and the bottom looks like a T-1 breakout module that's probably connected (wired) to the Telect DSX panel right below it. Cell sites were originally fed via T-3 (DS3) microwave, which then had a demux ("M13" pronounced M-1-3) which took the T-3 and broke it out to 28 T-1 lines. That was fed to the DSX panel,, and patched up to the Nokia router module (the white cables). That style of "trunking" is long gone, and now cell sites are either fed by 10GB Ethernet or OC-192 SONET microwave (or higher nowadays via dedicated underground fiber to accommodate 5G speeds). The Nokia routers also have a special clock timing option to sync the transport network together, which is important in how Cellular networks work.
BACK IN MY DAY lol, cell sites would only need 4 t-1s. They soon doubled every couple years when cdma came and improved. The latest and greatest is the fiber for c-band. 125 gig WDM muxers in each site.
Is that a Nokia? We just started installing SAR’s to replace sonet equipment, but we use Aviat radios for microwave. The shelves are very similar in size and design.
You brought back the memory of my dad pointing out microwave antennae, mounted all over the place, when we drove long distances on vacation. He worked for Bell Labs for 42 years, retiring in 1969, so he knew all that technology.
A great video on TH-cam is a Bell System 1968 film called "Without Fail.". Corn some reason it comes up as "The amazing unfailing Bell System. I watch it periodically to remind myself how great a system it was.
@@mepperganfortas The current AT&T is not the AT&T of old. After the breakup there was a lot of chaos that took place in both the Bell System and the telephone industry in general. To make a very long story short, as I mentioned in a previous comment, the former AT&T aka the Bell System aka Ma Bell was weakened to the point that it was taken over by one of her former "children" Southwest Bell Telephone. That entity took on the name of its former parent and became the AT&T we have today. The former AT&T was a MUCH BETTER organization than the AT&T that exists now.
Dad worked on Motorola two ways from the earliest I could remember then sold for Motorola for over 30 years. He too would explain the various towers we saw as I traveled with him: TD towers, Range stations, broadcast stations, comms stations, the works.
@ATI556, thanks for doing detailed walk-through and power up of the AT&T relay site. Since I was born in 1955 and made a career of servicing and designing transceivers, I found your video very interesting, especially since intact sites are very rare these days. I was never associated with telephone communication so, don't know any of the system design specifics. Making a long distance call in the 1970's sounded like the system was using supressed carrier single sideband with multiple channel banks. A friend in 1982 told me the large antenna horns had a front-to-back ratio of 80 dB, which was necessary since the input frequency was the same as the output frequency. That waveguide looks to be sized for 5 to 6 GHz. Of course, high frequency solid state devices were not available so, klystrons were probably used as transmitters in the original 1950's systems. Later, solid state RF power amps were used at lower frequencies, then multiplied up to the transmit frequency using varactor frequency multipliers.
They operated smack in the 4ghz satellite downlink C band. That is why up until the mid 1980s C band satellite receive stations also had to be licensed as the receiver LO could cause interference to the AT&T links. With the AT&T breakup and the proliferation of back yard C band receivers before scrambling, the FCC finally gave up on the C band receive license requirement.
@billharris6886, Yes, klystons were used for the MW modulators in the first TD-2 facilities. Then TH radio was developed using TWT modulators, which have less noise. Then TD-2 was improved by solid stating it and using TWT'S instead of Klystons, it was labeled TD-3. Then it all went digital.
It's incredible how many of these microwave sites appear to have been left completely untouched since decommissioning/cutover. Thank you for documenting the site!
A minor correction, if I may. Southwestern Bell Telephone & Telegraph was one of the Regional Bell Operating Companies (RBOC) of the former Bell System. Long Lines was the part of the legacy AT&T that quite literally was responsible for all of the cables and later, microwave communications. AT&T Long Lines ceased to exist after the Bell System breakup and long story short, Southwestern Bell eventually was able to "swallow" its former parent, AT&T. It took on its parent name and became the current AT&T.
It seems all the YT videos don't understand that Long Lines was a company owned by AT&T, and they also don't know that almost all of the equipment was made and installed by Western Electric, which was also owned by AT&T.
@williamjones4483, It's rather ironic to note that AT&T did the same thing to it's parent company way earlier. AT&T was formed by American Bell Telephone Co. In 1885 to build and operate long distance lines. In 1900, AT&T took over American Bell and the child swallowed the parent. 100 years later SBC (Southwestern Bell Co.) acquired AT&T and again the child swallowed the parent. But this time the AT&T name was retained. After the divestiture of the Bell System on 1/1/84, Western Electric and Bell Labs became part of AT&T, and the "Long Lines" term was dropped. The newly independent ex-Bell operating companies seemed to eventually all gobble up each other and now it's just AT&T. So the only thing the divestiture accomplished was the demise of the separate entities!
@@itz_mxxri Before the breakup in 1984 there existed AT&T COMPANY that was the parent. There was Bell Labs research and development, Western Electric manufacturing and installing and then AT&T Long Lines which handled long distance. There also existed at the time the Regional Bell Operating Companies or RBOC. The RBOC was what supplied you with local service and a long distance connection to the rest of the network. One of those RBOC's was Southwest Bell Telephone & Telegraph. I'm about to simplify things here so I hope it doesn't confuse you. The court ordered that AT&T Company divest itself of Western Electric and the RBOC's to say the least. Each of these units became its own business entity and proceeded to do whatever. In the meantime the former parent began to shrink because of the assets it was forced to give up. Southwest Bell Telephone changed its name to SBC and began to grow. Over time it became big enough that it was able to "swallow" or take over, its former parent. When it did so it took on the name of its former parent and began to call itself AT&T CORPORATION and that is the entity we have today. Some of the former bell System has reconstituted itself. AT&T Long Lines is no more as is Western Electric and Bell Labs which is owned by Nokia. From 1984 to current date there has been, for lack of a better term, much musical chairs going on. In short it was a takeover, not a merger. Go to Wikipedia's home page and type in the search box "breakup of the bell system". It explains events far better than I can.
I've already seen one difference between the old AT&T site and this cellular building. The AT&T site was built with love. The engineers back in those days took pride in their work. Cables were neatly dressed and bundled. The equipment was well placed and care given to its appearance in the racks. Today, equipment is thrown in racks and barely screwed in. Cables are not well managed or bundles to look halfway neat. The art of building a nice looking tower site seem to have gone by the wayside. But it's an interesting video, and thanks for sharing.
You're right about that! When my dad worked for PT&T and later AT&T back in the 60's, 70's and 80s, I'd go to work with him often. I remember watching the Western Electric guys doing their installation work, and it was a work of art that they took pride in!
That was nice to see one not vandalized all up. Very interesting stories about the whole entire system. The one thing I was trying to find out is when the last one was used. Never did find an exact date (For the original horns). Talk of around year 2000. Mostly a few places that was not worth running fiber to. Even then it was upgraded to more modern radios. I have few sites around me. One in my Home town I grew up in was purchased by a ham guy. Can't find any update on it and does not seem to be up-kept. The other building up on a mountain is still used and has the original horns and some new stuff. I think it is a fiber hub now. Then the other one was removed in early 2000 or something. The site and everything. So nothing left. I know of one other tower, but have not had a reason to drive that way. Once I do I'll be sure to take some pictures of it.
@idahofur, All of thsee microwave and carrier facilities were shut down by 1992. Totally replaced with fiber optic cables. So this DR6 facility was the last microwave developed and was only in service for 10 years or less!
This brings back memories of the days my dad worked for PT&T and later AT&T in the 60's, 70's and 80s. I went to work with him often. Before he retired, he worked in microwave, but it was all the old TD-2 and TH radio. This is the first time I've ever seen DR-6 . The latest facility I saw was called AR-6.
Thank you so much for helping to document the fascinating history of the long lines system. This is easily the most interesting video I've seen on it to date. It is so amazing to see a site that has most of the equipment in working order. I never thought I'd see somebody actually power up a site. It makes me wonder how many others are out there that are frozen in time, as if they were just simply switched off and left behind. I hope I get a chance like this someday
THANK YOU for capturing these images and publishing this video for all of us to see. I have always found the AT&T Long Lines system enigmatic and mysterious, and seeing the inside of a facility is indeed quite the treat...thanks!
You're lucky to have access to such amazing history! That was a newer long lines site too. Some of the videos that I've seen have much older equipment in them. Even some have tours of the bunker sites as well.
I kind of figured that was the case. I was a contractor for our local telco (which was bought out by Bell Canada in 2016, kind of a full circle story since our government had bought it from Bell in 1908) and have been in many CO's and seen a LOT of old switching equipment. No mechanical switches, but mostly Nortel DMS and a few Automatic Electric GTD-5 in very rural offices. This stuff looked newer than the stuff I saw!
I posted in a sub-comment but will repeat here: it looks to me like this is a very *late* technology version of the Long Lines system, probably updates not long before or even while the system was beginning to b4 phased out of use. The logo shown on the rectifiers, transmitter racks, and other systems is the post Bell breakup “Death Star” AT&T logo, which was first used in 1983. No less cool, but quite a bit more modern and MUCH smaller than the original fully vacuum tube hardware that would have been used when the first Long Lines stations went into service.
I remember it well when my dad was working for PT&T, and then on 1/1/84 he was suddenly working for AT&T! Nobody was happy with the break - up of the Bell System! So much confusion as to who would use the Bell logo, and no one liked the first AT&T globe logo! They put different colored tape and signs all over the office equipment rooms to designate what belonged to AT&T or Pacific Bell ! It was crazy!
This is really cool! The equipment with the cards in the blue racks is newer than you stated. That is digital microwave equipment from the mid-late 1980s. All of the analog sites were shut down by the early 90s, this site may have lasted a lot longer than that, since it has the newer digital equipment. There are still a few sites running today in AT&Ts network using these radios.
I believe that is FR8, AT&T’s last generation of analog microwave ( with the Death Star logo) though it could carry T1s from terminal to terminal. I worked on some in the 90s and even occasionally post Y2K, after I graduated college. It was cool to learn. The mux equipment was from Grainger, and when I was troubleshooting an issue, I ran across the statement that a circuit carrying a high speed modem required a pilot sync card to be installed in the shelf. Elsewhere high speed modem was defined as anything faster than 300 baud.
I can’t edit- analog means the radios take an analog input, called based band and mux it up to 70 MHz IF, than microwave. Digital systems digitally modulate the carrier using discrete I and Q signals. Analog microwave can carry digital signals using a modem, digital microwave can carry analog signals using a channel bank. We’ve run digital and analog on the same link at the same time ( but different frequencies). We may have been the first guys to disconnect the B channel of a FR-8 and replace it with digital microwave, while A still carried traffic with out interruption.
I can’t believe that powers up a runs! Usually electrolytic caps tend to fail from just sitting there. About half the older electronics I play with needed a cap or two replaced. Also the clock batteries always fail. Super impressed that you got it fired up, great vid!
I have been in many of the old MCI sites as well along with being on the towers working them. This was back in the mid 90's after they had decom'd and sold them already.
Amazing. Can’t believe AT&T left all the hardware there and in workable order. I’ve watched some vids of the underground telco bunkers and all equipment was removed.
Nice job on the tour, brings back some good memories. This was just a hair before my career in telecommunications but when he mentioned the rectifiers converting ac to 24V DC, I’ve never been in a CO or HUT that was not -48v DC.
Same here. All the telco central offices were 48 volt. I was not aware the relay sites were 24 volt. Most of those panels he referred to as processors were most likely multiplex units. This was not what we think of today as packet data. Voice channels were 64kb each and 24 of them became a T1 (1.544M) and then those were combined to a higher data rate and then modulated onto an RF carrier that was then upconverted to the actual Microwave Frequency. Unlike our in-home Wifi that is half duplex, these were full duplex units they had a TX channel and and RX channel for each. That must have been a newer SW Bell site. The older AT&T sites had really thick solid concrete walls that were like 18 inches thick. The one I was in a few years back even had a generator room. The generator was huge and was inside the building. Still a nice video 🙂
Yeah, I agree. Back in the days when my dad worked for the Bell System, all the equipment in the COs, repeater stations and huts operated on - 48 volts. Maybe this newer digital stuff is lower voltage.
This was such a great video! I have been fascinated by these sites since I was a kid. I'd look for them on long trips with my parents, seeing the huge red and white towers with gigantic horn antennas on top. I always day dreamed about what was inside of these buildings. There is a tower near me that still has the original horns, but they have seen better days. Keep up the great work!
Exactly. AT&T Long Lines. And every AT&T long lines site, from underground cable to microwave stations and repeaters carried the Autovon network. The traffic from the Autovon network commingled with normal traffic
That equipment was all upgraded in the 80's or 90's. Those are all digital radios. The 1950's Bell System Longlines network was all analog radios with analog A, L and other carriers. All of the equipment was gray and it had Bell System bell logos and said Western Electric in the old lightning font. The AT&T "Deathstar" logo didn't come into existence until 1984. When they first started to switch from analog to digital, they used transmuxes that would take T1 spans and convert them to an analog L carrier (and back) so they could be transmitted over the existing analog radios. That site is clearly newer than 1984.
Yes, that is true! The break - up of the Bell System occurred on 1/1/84, and that was the first globe logo AT&T used that no one liked. My dad worked for PT&T and on that date he suddenly was working for AT&T!
I heard that this actually has lower latency than a fiber optic line. Or at least that was true when a stock trader developed his own system of these going from New York stock exchange to Chicago's.
This was a great video. I remember back before they went digital I was trying to learn to phreak and fell in love with the idea of building a phone network to survive a nuclear exchange.
Whats funny is, I drove past one of those towers recently in my state wondering what the purpose of those were for. Looked unkept but still interesting to see.
Very well done and explained. I hope that someone might make a museum here, or on another of the many but now abandoned sites. I'd love to have a piece of memorabilia from this era. Keep making videos, and all the best! 73 DE W8LV BILL
The old school aluminum cornucopia P to P microwave antennas. These antennas RF all over the place compared to the UHD parabolic dishes with frequency specific feed horns. The shelters that housed the longline equipment was built to withstand heavy blasts, I just don’t know how big of a blast. These structures became a pain to deal with in the last couple decades because internal compliance found there to be asbestos used inside which got costly to remediate.
You may chuckle at this: We were still maintaining these 13:50 type of batteries on a Lucent 5ESS toll switch. (Still handling *live* traffic / calls).
Should definitely reach out to the Connections Museum in Seattle. They might could make use of that equipment in their restorations Ideally [and depending on location], some horns could be reinstalled and they could bring it back online as part of a functional link between museum sites
As a microwave engineer… I’m REALLY hoping the transmitters weren’t fully turned on to transmit… with the waveguides lopped off at the building and plates installed, that would act as an RF short and all that power would reflect back to the Tx… the finals would be cremated in short order 😖
Unpopular Opinion Ahead - As a broadcast engineer, I would have kept my hands off the equipment. Take the pictures I needed, and LEAVE without touching ANYTHING... Without knowing anything about the site... Nobody has any idea of the condition of the electrical, grounding, spurious emissions, and other functions of the site without a proper inspection and approval to turn the equipment on. That aside, I do give credit where credit is due. Great video and good simple description of everything that's in the site. Great piece of history and excellent show of PPE and safety knowledge. A sleeping beauty finally awakened...
@@MendotaTech I get what you are saying about powering that stuff up cold after 20+ years. I 'm also a close to retirement broadcast engineer and even collect old analog and early SDI gear. But sadly all that stuff we see here is headed for a land fill anyway.
Hahaha! As a Television Broadcast Engineer Specializing in ENG and dSNG 2,6,7,12 & 14 GHz and still a Satellite Uplink Truck OP; I gotta admit. I Scrutinized! 😜 I was looking at that Waveguide (likely close to 6GHz by it's size; It wasn't KU or X-Band waveguide. and I call it HARDguide) And when he was describing the Ice Bridge, There was no Flex Guide (or Transmission line) Heading out of the building! I took a close look at the panel and noticed most of the panel had light duty terminators placed on the ends, One or two were left open and I had to go back to when he turned the black knobs on the modulators. From the brief glimpse of the HPAs he gave us, the one or two HPAs that he did show WERE IN STANDBY!! Otherwise those little terminators would have turned into brake lights with forward drive on! There were NO Dummy Loads on that outside panel! I will say this: Long lines were replaced by Communications Satellites (that were even longer lines haha), performed the same job, but also allowed Simultaneous reception anywhere in the continental US. That's what killed long lines. Broadcasters like NBC, CBS, PBS and ABC could now send programming directly to specific Affiliates and disseminate primetime programming across the nation in just under 2 seconds. Now days, Fiber (including IP based) and Cellular Bonded modems are killing Satellite communications (and my career). And now, my head is filled with too much useless information regarding old and retired communications systems like this.
This is the first mention of frequency bands used on this system. Crazy to think that today, the 1-6 GHz band is the most valuable part of the entire radio spectrum. I would have expected that the 80-120 GHz band would have been used, as this range is unusable for satellite communication but is still in a range where atmospheric attenuation is not enough to block focused signals. But also thinking that we didn't have the electronic equipment at the time to reliably generate that frequency.
Good to see this stuff. In tthe 70"s and 80"s I worked for MCI and took care of installing and maintaining the frequency division multiplex that prepared the analog voice and data private line circuits. One microwave radio handled 2700 circuits until the conversion of the microwave from fm to single sideband doubled the capacity. By the late 80's and early 90's fiber was installed along highways, pipelines and railroads eventually making the microwave system obsolete. Satellites were also part of themix, but they had limitations on capacity and the delay caused a lot of issues...
All the technology you showed was 1980's or later, meaning the site was upgraded to newer technology. The site may have come online in the 1950's-1970's, but everything was replaced with the exception of the towers & building....
I’ve been to a lot of mountain tops as a comm tech that have old long lines sites, many with the horn antennas still up, but haven’t been able to see inside one until now. I’m sure very few have the equipment left inside.
Its really interesting how these systems worked and why they were built! I think that the main reason why these systems was built is that they provided a strategic communications link between the DEFENCE EARLY WARNING system up north in Alaska, Canada northern areas to the U.S defence and government leaders like you briefly mentioned! I believe that most of the funding to build these systems came from the US government. and the Bell systems to get these systems built as quickly as possible, It was indeed a HERCULEAN operation, especially in the frozen north! Many thanks for posting this video!
Back in the mid 70s, when I was working in Northern Ontario, I used to frequent a small town, in the middle of nowhere, called Armstrong (about 150 miles north of Thunder Bay), that had a USAF radar station, though it closed down shortly before my first visit there. However, there were a few other sites that were still active and I did some work in one in Falconbridge Ontario. They were part of the Pinetree line, which was the first radar line across the continent. I recall the circuits for the SAGE network, which connected the radar sites to some big computers, to keep track of enemy aircraft. The company I worked for was not part of Bell, though we often carried them into some remote communities.
There’s an old at&t Long Lines tower near Belton, Tx still standing. It’s now used by a wireless internet provider. The diesel generator is a relic, that can be a sweet project for an enthusiast to restore, if it can be recovered from the site.
That setup looks to be mostly 1980's tech. The round "Bell Cells" in plastic racks is a dead giveaway, as well as the light blue racks themselves. In the 70's and earlier the cells were rectangular and sat on rubber mats on heavy steel racks, and the equipment racks were all "Telco Gray". The blue Bell System symbol on the wall is from the 70's and the AT&T logo is from the 80's.
It's funny YT would recommend your channel to me today. I got to check out a very small, 80s AT&T built microwave repeater site yesterday and whats left of the AT&T equipment looked just like this! There was some DC stuff and a rack of channel banks and patch panels left and the (I believe) original Generac propane generator is still in use and works just fine. Excellent video btw. Modern comm facilities are so boring in comparison to this stuff.
I wish I could show you some old C system analog carriers for open wire lines. They were built with vacuum tubes and date from the 1930s. They had something called a "Sensitrol relay" to measure the signal level and then operate a motor to crank the gain up or down. Depending on the model, they could carry 3 or 4 voice channels on a pair of wires. You often see open wire lines in old movies, particularly near railroads.
@james_Knott, Yes, my dad worked for the Bell System in the 60's, 70's and 80s. I've seen all of that old equipment including C carrier bays, but it was all retired in place. I was always fascinated with the old telephone facilities. Especially open wire. It's all gone now! I do miss it.
This is not a long lines site. The tower and equipment all indicate that it is simply a mid 90’s cell site. The land wasn’t even leased to AT&T until 1995, long after the breakup of the Bell System.
I was told, after I hired in as a systems tech for SWBT, in 1999, that those big old batteries were the same batteries they use on submarines. Even though I was a U.S. Navy submariner for 6 years, I can’t confirm that. Our batteries were hidden away in the battery compartment in the forward bottom part of the sub, which the interior communications (“IC men”) guys took care of. (I worked on ballistic missiles.) They’ll definitely hold a charge for a while. They were full of clear sulfuric acid, and the containers were clear as well. So when that site gets gutted out, that’ll be a big hazardous ⚠️ waste issue for them.
I am sure @ConnectionsMuseum would love to perhaps get their hands on some of this equipment so it can be preserved and perhaps used to set up a RF-hardline demo
Man I love this old stuff, it's so cool where we are today with technology and all but all this old stuff that got us here back then is awesome to understand. Who knows, one day we might have to power up that old robust stuff in the bomb proof shelters...
That old C band network was 4/6 GHz. The network handled what ever the phone company did. While telephone and TV were certainly a large part of it, they also handled data, though not to the level of today. I recall working on the multiplexing equipment. Starting at the bottom was what was called "Voice Frequency Carrier Telegraphy" (VFCT) which connected the old teletype and similar circuits over a voice channel. Then the voice channels were grouped and carried over either microwave, open wire lines or the new fangled digital T1 system. In microwave the channels were bundled into groups and super groups, to be carried over the radio link. Back in those days, a modem, which might be as fast as 2400B, required a dedicated, conditioned circuit and when carried over microwave were not placed on channels near the edge of the group, as the filter roll off would reduce the bandwidth of the voice channel. Also, those towers did not "broadcast". Broadcast is a specific term in telecom, which means from one point to many, as with radio broadcasts. Microwave links are point to point, with the signal focused on the other end. In fact, broadcast is one thing they did not want to do because a) it's a waste of signal and b) it might interfere with something else. A lot of telecom gear is -48V and if you have 3 power supplies, you likely need only 2, with the 3rd for redundancy, in case of failure. You should be able to pull out 1, without affecting anything. You say that equipment is old, but in fact looks fairly new. The stuff I used to work on was a lot older. For example, the batteries were in glass, not plastic. It sounds like you're confusing hard line with wave guide. You had shown wave guide earlier then started talking about hard line. Hard line is essentially rigid coaxial cable, but those microwave sites usually used wave guide as even hard line coax had too much loss. Anything with an 8 bit CPU is no older than 1974 or so. That shelf you were leaning on, near the end, appears to be a DSX panel. where DS1 (T1) 1.544 Mb circuits were cross connected.
Being from KCMO I remember the AT&T building downtown that had the large microwave antennas on the top of the building. I wonder if that site talked directly to the site near me in Ks. Is there any maps on what towers were connected to what tower? There was a long lines site about 6-7 miles from my house. A number of years ago all the old microwave antennas were removed so now the site does not look so much like a long lines site. Would have been cool to see in the building. Probable been cleaned out now.
IDK about the later generation of radios in this site but the older ones were give or take DS3 equivalent. That MPR in the mobility site can do a lot more than 5x that though it probably was licensed for some lower bitrate. Plus mobility configures their MPRs to be redundant, so instead of 6 individual EASV2 cards, the chassis is split primary and secondary so you really only have 3 pairs of EASV2 cards(or EAC10G etc) to allow fail over.
I can tell you that the Analog Video portion would have been36MHz each. That would have dropped down to a minimum of 6MHz when digital video modems came into play.
The really old sites would have been analog, with multiplexing to create groups and super groups. Later on, digital signal were used to modulate the microwave signal.
For the most part the microwave and other transmission equipment is powered by lead acid cells. I’ve seen nickel-iron and other alkaline cells used as start batteries for the on-site diesel generators or turbines if the site has them, although sometimes they are the more standard automotive lead acid type.
in nov im taking my 4x4 group to check out the long lines equipment bunker on razor rd near barstow ca. there is also a unmarked att microwave antenna close to anza borreigo. down town LA has an interesting building next to the Japanese embassy, similar to that spooky building in New York.
That old bunker was once a L3 carrier main repeater station near Baker, CA. Back in the 70's the PT&T com. techs called it Beacon underground. Unfortunately vandals broke into it and destroyed everything and stole all the copper! It makes me sick because I was down there once back in 1978 when it was still in operation.
great in depth explanations ! With the project being dead, very surprised everything was still in working order. Is this for preservation, or simply abandoned in place? I would have thought everything would be powered down except for required tower lighting circuits.
This is really cool, i live 30 min away from Fayetteville, Ar. And was wondering where this location is. I know there is some old sites close to fort smith along i40.
There are still a set of AT&T Long Lines towers still standing in a small city in Middle TN. There is a building below the towers. There's always a car there, so I am not sure what AT&T is using this building for, and why these towers have stayed there for so long. Doesn't seem to host any DSL c/o. and its not running any active antennas for cell data. Do you know where this is?
FYI: AT&T created this nationwide System Built in the 60s and used till the 90s 3 Ghz to 4.2 GHz L4 cables buried ran to these sites as well They carried phone and TV The 100 foot satellite dishes in the 70s were hooked up and they are still in use today. I have been in the LL sites and in the Teleport sites and seeing these dishes was a huge thrill every day.
6 Gig as well. late 40s they had some experimental routes going, 1951 they had a transcon microwave path NY to SF. A good bit of it was shut down in 92, replaced by fiber optics.
@@davewood406 I remember in 99,00the new fiber was being trenched along the highways. I worked at a government facility and our data went slowly. I remember the morning the first fiber went online and the speed was so fast. The copper was maxed out all the time and it went from 100% capacity to.0001 capacity in a matter of seconds. It really changed the world
@@ocsrc If you're not familiar with DWDM and CWDM fiber tech, dig in. Just an upgrade at the equipment at the ends, as long as the existing fibers are in good shape, they can carry a lot more data.
@@davewood406 pre-99 in our area we had fiber run by the cable company between the major cities on poles, but when AT&T ran the new fiber, I was driving a lot back and forth 300 miles each way, and they trenched and buried 8 plastic conduits along the utility ROW where the old copper was, and they installed the flower pots. That was handled by a third party, then they ran the fiber and they only ran just one of the conduit and they built a new switching center underground where the two interstates interchange was. They connected into the COs in the major metro areas, 6 cities in my state. Seeing the giant metal jacket L4 cables and the tiny fiber and the fact that it could carry hundreds of thousands the amount of data, it makes me wonder what we will have 50 years from now. I remember when C-band first started and cell phones when only the phone company had them on the 30 MHz low band, and then 800 MHz commercial cell phones, and Ku band when it first came out and was experimental. And now C-band is about to be retired from satellite service and transferred to cell phone use. I have seen the laser communication used for satellites and I have seen it used from the ground station, even tracking the moving satellites. The beam was only visible when you wore the special glasses to see laser light. I just wonder if that will replace the fiber one day. At least from metro area to metro area. I still remember dial up at 300 baud And the first fax machines And the first gateways to dial in to the Internet. Young people who have never known a Time without smartphones don't understand what it was like before the revolution. It was peaceful and quiet but there was a lot of down time. I sit at restaurants or in doctor offices and I think about what it was like waiting 20 or 30 minutes, just sitting doing nothing and how boring it was. I really hope I live to see the brain implant to communicate with our digital devices. Just think turn off the master bedroom lights and Alexa will read our thoughts and turn them off. And self driving cars, that we can just go to sleep and wake up 10 hours later and be at our destination. It will change the world, again.
@@ocsrc I used to work for the telecommunications division of Canadian National Railway, which later merged with the same from Canadian Pacific. Our fibres went along the tracks.
I do believe they're a nickel-iron battery look up Edison batteries you can go down the rabbit hole of when exide battery purchased them and switch them all out to lead acid did the Edison battery last and definitely just drain out the electrolyte every 50 years
@@kurtzxcvb3481 I saw a life expectancy chart tucked into a round cell stand when we removed some and I forget exactly but somewhere around 70 degrees they expected 100 years of service. Assuming proper maintenance of course. A warmer room diminished life quite a bit. Still better than the VRLA they use now though.
I’m gonna burst some bubbles and suggest that this was not a long lines site. Nothing in this site appears to be from any earlier than the mid 80s. The circuit breakers, the processors, etc. Even the tower structure.
There were some Long Lines sites built like this one after 1983 (post Bell System divestiture). Some still exist today, but instead of using analog or digital microwave radio to access or regenerate the network signal, they typically use fiber optic equipment.
The fun thing with the waveguides is sizing everything for the frequency. Everything from the bends to the runs had to be sized correctly to a multiple of the wavelength or else you would cause reflections and destructive interference. So when racks and equipment needed to be placed in the room you had a relatively (for rack work) tight tolerance on where everything needs to sit. I don't know how AT&T did it when they were laying out these buildings, but often it was easier to get the racks in the general vicinity and not bolt them to the floor, or leave very oversized holes in the bottom plates of the rack. That way when doing final assembly and fit up of everything you were free to nudge the rack over, or put shims under them. Then after all the tests you would just torque everything down in place. Because it just always seemed to be the case that the tower or entry hole through the building was just constructed to 0.25-2 inches off from the plans and you had to compensate by moving everything else.
Strap in... Pre divestiture it was all one but there were business groups with separate responsibilities, so up until 1984 it was the Long Lines Division of AT&T. Though for some reason the Pacific Bell region, Long Lines was handled by Pacific Bell. Which as the RBOCs reorganized, merged and whatnot after Divestiture became Southwestern Bell(SBC then AT&T as it exists today) So that might be what tripped him up. I want to say Long Lines stayed part of what was left of Ma Bell at least for a while but you need a map for the Splits and mergers post Divestiture... I'd hope someone could paint a clearer picture but they way it played out was a mess and easy to get things confused.
@@James_Knott There was a discussion about that a few months ago, the Pacific/Nevada Bell region specifically. it was the same network and whatnot but technically the folks handling the day to day operations were Pacific/Nevada Bell. It was still AT&T Long Lines. I didn't take from that discussion that PB operated it independently. Likely a distinction without a difference other than to the bean counters and lawyers. It may have been more or less than that but thats just how the discussion painted it.
@davewood406, Hi, we meet again! Yes you are exactly right in everything about the Bell System divestiture. Before 1/1/84 Pacific Telephone and Nevada Bell were the only Bell operating companies maintaining their toll facilities, the rest of the country was all AT&T Long Lines. On 1/1/84 my dad , who worked for PT&T, was suddenly working for AT&T! Nobody liked it! And PT&T became Pacific Bell and the term "Long Lines" was dropped. They put different colored tape and different colored signs all over the equipment rooms in the toll offices designating what belonged to AT&T or Pacific Bell ! It was crazy!
This was neat! For your role do you actually need to know math beyond arithmetic and be able to calculate things by hand? Or just an awareness of what the application is doing enough?
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I imagine some of those racks had multiplexers in them. It's amazing you were able to power up the building after 25+ years. It is a testament to the quality of AT&T manufacturing that nothing shorted, blew-up, or caught fire. I was waiting for the magic smoke. 😁
Something most definitely broke, just didn't let out the magic smoke 😅
Yes, there were no flaming capacitors! Even the LEDs inside of the AT&T Trimline phone work.
I work in telecommunications, that is an active hut. There is fiber optics in that hut.
@@Mike-ij9vj I can 100 percent confirm there are no active fiber systems in the old longline hut.
Bro, go to the communications museum in Seattle Washington. I’m from Wisconsin and I’ve flown out there 6 times already this year to see their stuff. They have 2 warehouse sized floors of working telephone switching equipment from Stroger switches, step-by-step switches, cross bar switches, microwave carriers, you name it. It’s only open on Sundays though from 10 AM to 4 PM. There is no entry fee but leave a donation is encouraged.
They also have a ton of engineers our age there who work alongside with all Bell System engineers. All the equipment can be played with and you can ask all the questions you want. It’s awesome. Plan your next trip there
@@cameronweston1762that sounds awesome, did they have broadcast Tx equipment too?
@@TheMW2informerthey do. I worked on trying to get some carrier systems working there a couple of years ago myself :)
they also have a TH-cam channel, they post a lot of great videos
TH-cam suggested this probably because I'm a technology geek. Thanks for this video. It shows how well prepared our country always tries to be to ensure we have highly reliable government and military communications if things were to get serious. Excellent presentation.
The nuclear continuity plan is to destroy all other countries entirely to save what they can of the US. We're all dead once there's no food, no low-cost Chinese manufactering which is essential now, no ships crossing the ocean. Remember COVID and supply chain problems? You ain't seen nothing. All outbound missiles are pretargetted there are no options for surviving nuclear war other than to hope we hit them before they hit us. They have us convinced that they're going to protect us. With what? I don't want to survive such an eventl Nuclear winter, no energy, no water, no food. Good times.
The "Microwave module" is actually a Nokia router with different module options (Verizon uses those Nokias). The top slots looks like fiber optic interfaces, and the bottom looks like a T-1 breakout module that's probably connected (wired) to the Telect DSX panel right below it. Cell sites were originally fed via T-3 (DS3) microwave, which then had a demux ("M13" pronounced M-1-3) which took the T-3 and broke it out to 28 T-1 lines. That was fed to the DSX panel,, and patched up to the Nokia router module (the white cables). That style of "trunking" is long gone, and now cell sites are either fed by 10GB Ethernet or OC-192 SONET microwave (or higher nowadays via dedicated underground fiber to accommodate 5G speeds). The Nokia routers also have a special clock timing option to sync the transport network together, which is important in how Cellular networks work.
BACK IN MY DAY lol, cell sites would only need 4 t-1s. They soon doubled every couple years when cdma came and improved.
The latest and greatest is the fiber for c-band. 125 gig WDM muxers in each site.
Is that a Nokia? We just started installing SAR’s to replace sonet equipment, but we use Aviat radios for microwave. The shelves are very similar in size and design.
@@SovietRobot69 Yeah, Nokia MPR9500, same as the Alcatel units.
T1 breakout = channel bank?
Seems rather slow. T1 Was 1.5Mb per copper line. Yes at the time 1.5 Mb was quiye fast, but for the amount of data going through, it seems slow.
You brought back the memory of my dad pointing out microwave antennae, mounted all over the place, when we drove long distances on vacation. He worked for Bell Labs for 42 years, retiring in 1969, so he knew all that technology.
A great video on TH-cam is a Bell System 1968 film called "Without Fail.". Corn some reason it comes up as "The amazing unfailing Bell System. I watch it periodically to remind myself how great a system it was.
@@mepperganfortas The current AT&T is not the AT&T of old. After the breakup there was a lot of chaos that took place in both the Bell System and the telephone industry in general. To make a very long story short, as I mentioned in a previous comment, the former AT&T aka the Bell System aka Ma Bell was weakened to the point that it was taken over by one of her former "children" Southwest Bell Telephone. That entity took on the name of its former parent and became the AT&T we have today. The former AT&T was a MUCH BETTER organization than the AT&T that exists now.
Dad worked on Motorola two ways from the earliest I could remember then sold for Motorola for over 30 years. He too would explain the various towers we saw as I traveled with him: TD towers, Range stations, broadcast stations, comms stations, the works.
@ATI556, thanks for doing detailed walk-through and power up of the AT&T relay site. Since I was born in 1955 and made a career of servicing and designing transceivers, I found your video very interesting, especially since intact sites are very rare these days.
I was never associated with telephone communication so, don't know any of the system design specifics. Making a long distance call in the 1970's sounded like the system was using supressed carrier single sideband with multiple channel banks. A friend in 1982 told me the large antenna horns had a front-to-back ratio of 80 dB, which was necessary since the input frequency was the same as the output frequency. That waveguide looks to be sized for 5 to 6 GHz. Of course, high frequency solid state devices were not available so, klystrons were probably used as transmitters in the original 1950's systems. Later, solid state RF power amps were used at lower frequencies, then multiplied up to the transmit frequency using varactor frequency multipliers.
They operated smack in the 4ghz satellite downlink C band. That is why up until the mid 1980s C band satellite receive stations also had to be licensed as the receiver LO could cause interference to the AT&T links. With the AT&T breakup and the proliferation of back yard C band receivers before scrambling, the FCC finally gave up on the C band receive license requirement.
@@andydelle4509 Thanks for the system frequency history, very interesting!
@billharris6886, Yes, klystons were used for the MW modulators in the first TD-2 facilities. Then TH radio was developed using TWT modulators, which have less noise. Then TD-2 was improved by solid stating it and using TWT'S instead of Klystons, it was labeled TD-3. Then it all went digital.
@@itz_mxxri Thanks for the info; very interesting!
It's incredible how many of these microwave sites appear to have been left completely untouched since decommissioning/cutover. Thank you for documenting the site!
A minor correction, if I may. Southwestern Bell Telephone & Telegraph was one of the Regional Bell Operating Companies (RBOC) of the former Bell System. Long Lines was the part of the legacy AT&T that quite literally was responsible for all of the cables and later, microwave communications. AT&T Long Lines ceased to exist after the Bell System breakup and long story short, Southwestern Bell eventually was able to "swallow" its former parent, AT&T. It took on its parent name and became the current AT&T.
So much for stopping monopoly capitalism. Our government is bought and paid for by these companies.
It seems all the YT videos don't understand that Long Lines was a company owned by AT&T, and they also don't know that almost all of the equipment was made and installed by Western Electric, which was also owned by AT&T.
@williamjones4483, It's rather ironic to note that AT&T did the same thing to it's parent company way earlier. AT&T was formed by American Bell Telephone Co. In 1885 to build and operate long distance lines. In 1900, AT&T took over American Bell and the child swallowed the parent. 100 years later SBC (Southwestern Bell Co.) acquired AT&T and again the child swallowed the parent. But this time the AT&T name was retained. After the divestiture of the Bell System on 1/1/84, Western Electric and Bell Labs became part of AT&T, and the "Long Lines" term was dropped. The newly independent ex-Bell operating companies seemed to eventually all gobble up each other and now it's just AT&T. So the only thing the divestiture accomplished was the demise of the separate entities!
I've heard conflicting stories and I'm not sure which one is true. Did SBC actually take over AT&T or did they merge? Does anyone know for sure?
@@itz_mxxri Before the breakup in 1984 there existed AT&T COMPANY that was the parent. There was Bell Labs research and development, Western Electric manufacturing and installing and then AT&T Long Lines which handled long distance. There also existed at the time the Regional Bell Operating Companies or RBOC. The RBOC was what supplied you with local service and a long distance connection to the rest of the network. One of those RBOC's was Southwest Bell Telephone & Telegraph. I'm about to simplify things here so I hope it doesn't confuse you. The court ordered that AT&T Company divest itself of Western Electric and the RBOC's to say the least. Each of these units became its own business entity and proceeded to do whatever. In the meantime the former parent began to shrink because of the assets it was forced to give up. Southwest Bell Telephone changed its name to SBC and began to grow. Over time it became big enough that it was able to "swallow" or take over, its former parent. When it did so it took on the name of its former parent and began to call itself AT&T CORPORATION and that is the entity we have today. Some of the former bell System has reconstituted itself. AT&T Long Lines is no more as is Western Electric and Bell Labs which is owned by Nokia. From 1984 to current date there has been, for lack of a better term, much musical chairs going on. In short it was a takeover, not a merger. Go to Wikipedia's home page and type in the search box "breakup of the bell system". It explains events far better than I can.
I've already seen one difference between the old AT&T site and this cellular building. The AT&T site was built with love. The engineers back in those days took pride in their work. Cables were neatly dressed and bundled. The equipment was well placed and care given to its appearance in the racks. Today, equipment is thrown in racks and barely screwed in. Cables are not well managed or bundles to look halfway neat. The art of building a nice looking tower site seem to have gone by the wayside.
But it's an interesting video, and thanks for sharing.
You're right about that! When my dad worked for PT&T and later AT&T back in the 60's, 70's and 80s, I'd go to work with him often. I remember watching the Western Electric guys doing their installation work, and it was a work of art that they took pride in!
I loved the edit of the equipment lighting up in the dark that was sick
That was nice to see one not vandalized all up. Very interesting stories about the whole entire system. The one thing I was trying to find out is when the last one was used. Never did find an exact date (For the original horns). Talk of around year 2000. Mostly a few places that was not worth running fiber to. Even then it was upgraded to more modern radios. I have few sites around me. One in my Home town I grew up in was purchased by a ham guy. Can't find any update on it and does not seem to be up-kept. The other building up on a mountain is still used and has the original horns and some new stuff. I think it is a fiber hub now. Then the other one was removed in early 2000 or something. The site and everything. So nothing left. I know of one other tower, but have not had a reason to drive that way. Once I do I'll be sure to take some pictures of it.
There’s a guy on Facebook that maintains data on active sites. There’s still one or two active sites using the original microwave horns.
@@thecooldude9999 You don't have the link for that do you?
@@idahofur You tube tends to block links / even the hint of a link so be aware if you don't get a reply.
@@bobroberts2371 That’s what happened :(
@idahofur, All of thsee microwave and carrier facilities were shut down by 1992. Totally replaced with fiber optic cables. So this DR6 facility was the last microwave developed and was only in service for 10 years or less!
This brings back memories of the days my dad worked for PT&T and later AT&T in the 60's, 70's and 80s. I went to work with him often. Before he retired, he worked in microwave, but it was all the old TD-2 and TH radio. This is the first time I've ever seen DR-6 . The latest facility I saw was called AR-6.
Thank you so much for helping to document the fascinating history of the long lines system. This is easily the most interesting video I've seen on it to date. It is so amazing to see a site that has most of the equipment in working order. I never thought I'd see somebody actually power up a site. It makes me wonder how many others are out there that are frozen in time, as if they were just simply switched off and left behind. I hope I get a chance like this someday
Glad you enjoyed it!
THANK YOU for capturing these images and publishing this video for all of us to see. I have always found the AT&T Long Lines system enigmatic and mysterious, and seeing the inside of a facility is indeed quite the treat...thanks!
You're lucky to have access to such amazing history! That was a newer long lines site too. Some of the videos that I've seen have much older equipment in them. Even some have tours of the bunker sites as well.
I kind of figured that was the case. I was a contractor for our local telco (which was bought out by Bell Canada in 2016, kind of a full circle story since our government had bought it from Bell in 1908) and have been in many CO's and seen a LOT of old switching equipment. No mechanical switches, but mostly Nortel DMS and a few Automatic Electric GTD-5 in very rural offices. This stuff looked newer than the stuff I saw!
I posted in a sub-comment but will repeat here: it looks to me like this is a very *late* technology version of the Long Lines system, probably updates not long before or even while the system was beginning to b4 phased out of use. The logo shown on the rectifiers, transmitter racks, and other systems is the post Bell breakup “Death Star” AT&T logo, which was first used in 1983. No less cool, but quite a bit more modern and MUCH smaller than the original fully vacuum tube hardware that would have been used when the first Long Lines stations went into service.
I remember it well when my dad was working for PT&T, and then on 1/1/84 he was suddenly working for AT&T! Nobody was happy with the break - up of the Bell System! So much confusion as to who would use the Bell logo, and no one liked the first AT&T globe logo! They put different colored tape and signs all over the office equipment rooms to designate what belonged to AT&T or Pacific Bell ! It was crazy!
This is really cool!
The equipment with the cards in the blue racks is newer than you stated. That is digital microwave equipment from the mid-late 1980s. All of the analog sites were shut down by the early 90s, this site may have lasted a lot longer than that, since it has the newer digital equipment.
There are still a few sites running today in AT&Ts network using these radios.
Ah, I see you talked about them being digital. That’s what I get for commenting before watching the whole video :)
In particular anything with the AT&T “death star”logo on it is from 1983 or later.
I believe that is FR8, AT&T’s last generation of analog microwave ( with the Death Star logo) though it could carry T1s from terminal to terminal. I worked on some in the 90s and even occasionally post Y2K, after I graduated college. It was cool to learn. The mux equipment was from Grainger, and when I was troubleshooting an issue, I ran across the statement that a circuit carrying a high speed modem required a pilot sync card to be installed in the shelf. Elsewhere high speed modem was defined as anything faster than 300 baud.
I can’t edit- analog means the radios take an analog input, called based band and mux it up to 70 MHz IF, than microwave. Digital systems digitally modulate the carrier using discrete I and Q signals. Analog microwave can carry digital signals using a modem, digital microwave can carry analog signals using a channel bank. We’ve run digital and analog on the same link at the same time ( but different frequencies). We may have been the first guys to disconnect the B channel of a FR-8 and replace it with digital microwave, while A still carried traffic with out interruption.
I can’t believe that powers up a runs! Usually electrolytic caps tend to fail from just sitting there. About half the older electronics I play with needed a cap or two replaced. Also the clock batteries always fail.
Super impressed that you got it fired up, great vid!
I have been in many of the old MCI sites as well along with being on the towers working them. This was back in the mid 90's after they had decom'd and sold them already.
Amazing. Can’t believe AT&T left all the hardware there and in workable order. I’ve watched some vids of the underground telco bunkers and all equipment was removed.
Nice job on the tour, brings back some good memories. This was just a hair before my career in telecommunications but when he mentioned the rectifiers converting ac to 24V DC, I’ve never been in a CO or HUT that was not -48v DC.
Same here. All the telco central offices were 48 volt. I was not aware the relay sites were 24 volt. Most of those panels he referred to as processors were most likely multiplex units. This was not what we think of today as packet data. Voice channels were 64kb each and 24 of them became a T1 (1.544M) and then those were combined to a higher data rate and then modulated onto an RF carrier that was then upconverted to the actual Microwave Frequency. Unlike our in-home Wifi that is half duplex, these were full duplex units they had a TX channel and and RX channel for each.
That must have been a newer SW Bell site. The older AT&T sites had really thick solid concrete walls that were like 18 inches thick. The one I was in a few years back even had a generator room. The generator was huge and was inside the building.
Still a nice video
🙂
Yeah, I agree. Back in the days when my dad worked for the Bell System, all the equipment in the COs, repeater stations and huts operated on - 48 volts. Maybe this newer digital stuff is lower voltage.
Amazing still working, I still remember the sound of the diferents types of rings for the central offices before the modern standard ring came out
Algorithm recommended you channel to me, and it's AWESOME. Keep the videos coming!
You are producing some amazing and interesting videos. Thank You!
Time 845 " The chair is just chillin. . " ( The Proper People )
This was such a great video! I have been fascinated by these sites since I was a kid. I'd look for them on long trips with my parents, seeing the huge red and white towers with gigantic horn antennas on top. I always day dreamed about what was inside of these buildings. There is a tower near me that still has the original horns, but they have seen better days. Keep up the great work!
Southwestern Bell? No, give a look to AT&T (old pre-SBC merger) LongLines, and they're still in service in some locations to this date.
Exactly. AT&T Long Lines. And every AT&T long lines site, from underground cable to microwave stations and repeaters carried the Autovon network. The traffic from the Autovon network commingled with normal traffic
Some friends of mine in a local ham radio club own the tower north of Dover. It still has the waveguides and horns
This is just so cool to see. I cant thank you enough for capturing this and explaining it. This history needs to be preserved.
That equipment was all upgraded in the 80's or 90's. Those are all digital radios. The 1950's Bell System Longlines network was all analog radios with analog A, L and other carriers. All of the equipment was gray and it had Bell System bell logos and said Western Electric in the old lightning font. The AT&T "Deathstar" logo didn't come into existence until 1984. When they first started to switch from analog to digital, they used transmuxes that would take T1 spans and convert them to an analog L carrier (and back) so they could be transmitted over the existing analog radios. That site is clearly newer than 1984.
There was also that label that said 1984. 🙂
Yes, that is true! The break - up of the Bell System occurred on 1/1/84, and that was the first globe logo AT&T used that no one liked. My dad worked for PT&T and on that date he suddenly was working for AT&T!
Phantastic video! Thanks alot for sharing all of this, well done! What a pleasure to see the "good old days" tech ;)
I heard that this actually has lower latency than a fiber optic line.
Or at least that was true when a stock trader developed his own system of these going from New York stock exchange to Chicago's.
Thank you for your time creating and posting this. Appreciate it. :D
This was a great video. I remember back before they went digital I was trying to learn to phreak and fell in love with the idea of building a phone network to survive a nuclear exchange.
Your videos are very interesting. I work as an OSP fiber splicer in north GA. I rarely get to see the inside equipment. Keep it up!!!
Whats funny is, I drove past one of those towers recently in my state wondering what the purpose of those were for. Looked unkept but still interesting to see.
Very well done and explained. I hope that someone might make a museum here, or on another of the many but now abandoned sites. I'd love to have a piece of memorabilia from this era. Keep making videos, and all the best! 73 DE W8LV BILL
My wife says she has a piece of memorabilia from that era. DE KL7DL
You could probably find this old gear at Goodwill.. hahaha... (😳 Not Joking!)
The old school aluminum cornucopia P to P microwave antennas. These antennas RF all over the place compared to the UHD parabolic dishes with frequency specific feed horns. The shelters that housed the longline equipment was built to withstand heavy blasts, I just don’t know how big of a blast. These structures became a pain to deal with in the last couple decades because internal compliance found there to be asbestos used inside which got costly to remediate.
This is definitely a newer long lines site. That tower does not look like the classic LL tower.
You may chuckle at this: We were still maintaining these 13:50 type of batteries on a Lucent 5ESS toll switch. (Still handling *live* traffic / calls).
Should definitely reach out to the Connections Museum in Seattle. They might could make use of that equipment in their restorations
Ideally [and depending on location], some horns could be reinstalled and they could bring it back online as part of a functional link between museum sites
i second this. it would be very cool of that museum to preserve all of this!
Me Three!
As a microwave engineer… I’m REALLY hoping the transmitters weren’t fully turned on to transmit… with the waveguides lopped off at the building and plates installed, that would act as an RF short and all that power would reflect back to the Tx… the finals would be cremated in short order 😖
No transmitters were harmed in the making of this video. They were not powered on.
Unpopular Opinion Ahead - As a broadcast engineer, I would have kept my hands off the equipment. Take the pictures I needed, and LEAVE without touching ANYTHING...
Without knowing anything about the site... Nobody has any idea of the condition of the electrical, grounding, spurious emissions, and other functions of the site without a proper inspection and approval to turn the equipment on.
That aside, I do give credit where credit is due. Great video and good simple description of everything that's in the site. Great piece of history and excellent show of PPE and safety knowledge. A sleeping beauty finally awakened...
People can be cremated - not inanimate objects.
@@MendotaTech I get what you are saying about powering that stuff up cold after 20+ years. I 'm also a close to retirement broadcast engineer and even collect old analog and early SDI gear. But sadly all that stuff we see here is headed for a land fill anyway.
Hahaha! As a Television Broadcast Engineer Specializing in ENG and dSNG 2,6,7,12 & 14 GHz and still a Satellite Uplink Truck OP; I gotta admit. I Scrutinized! 😜 I was looking at that Waveguide (likely close to 6GHz by it's size; It wasn't KU or X-Band waveguide. and I call it HARDguide) And when he was describing the Ice Bridge, There was no Flex Guide (or Transmission line) Heading out of the building! I took a close look at the panel and noticed most of the panel had light duty terminators placed on the ends, One or two were left open and I had to go back to when he turned the black knobs on the modulators. From the brief glimpse of the HPAs he gave us, the one or two HPAs that he did show WERE IN STANDBY!! Otherwise those little terminators would have turned into brake lights with forward drive on! There were NO Dummy Loads on that outside panel!
I will say this: Long lines were replaced by Communications Satellites (that were even longer lines haha), performed the same job, but also allowed Simultaneous reception anywhere in the continental US. That's what killed long lines. Broadcasters like NBC, CBS, PBS and ABC could now send programming directly to specific Affiliates and disseminate primetime programming across the nation in just under 2 seconds. Now days, Fiber (including IP based) and Cellular Bonded modems are killing Satellite communications (and my career). And now, my head is filled with too much useless information regarding old and retired communications systems like this.
This is the first mention of frequency bands used on this system. Crazy to think that today, the 1-6 GHz band is the most valuable part of the entire radio spectrum. I would have expected that the 80-120 GHz band would have been used, as this range is unusable for satellite communication but is still in a range where atmospheric attenuation is not enough to block focused signals. But also thinking that we didn't have the electronic equipment at the time to reliably generate that frequency.
That was fascinating! Nice overview. Thank you.
Good to see this stuff. In tthe 70"s and 80"s I worked for MCI and took care of installing and maintaining the frequency division multiplex that prepared the analog voice and data private line circuits. One microwave radio handled 2700 circuits until the conversion of the microwave from fm to single sideband doubled the capacity. By the late 80's and early 90's fiber was installed along highways, pipelines and railroads eventually making the microwave system obsolete. Satellites were also part of themix, but they had limitations on capacity and the delay caused a lot of issues...
Great to see this from the inside. Relics from a post Cold War era. Still functioning after 32 years in hibernation.
All the technology you showed was 1980's or later, meaning the site was upgraded to newer technology. The site may have come online in the 1950's-1970's, but everything was replaced with the exception of the towers & building....
My thoughts also.
I’ve been to a lot of mountain tops as a comm tech that have old long lines sites, many with the horn antennas still up, but haven’t been able to see inside one until now. I’m sure very few have the equipment left inside.
damn that is interesting the fact that AT&T still maintain that king of equipement at least when the bomb fell communication can be restored
Unlike Cell Phones, Hardline phones (Ma Bell/At&T) were federally mandated to a specific functional "Up Time" of: 99.997%.
@@miketomas8564 oh that why well keep up the good work out there and have an excellent day
I think those air/pneumatic components are diaphragm pressure switches made by Dwyer that alarm if the pressure drops in the waveguides.
Yep, they are the newer style pressure switches. Long Lines sites mostly used Mercoid switches before that.
THAT, was awesome! Thanks for sharing!
Nice, reminds me of my IBM Mainframe days
Its really interesting how these systems worked and why they were built! I think that the main reason why these systems was built is that they provided a strategic communications link between the DEFENCE EARLY WARNING system up north in Alaska, Canada northern areas to the U.S defence and government leaders like you briefly mentioned! I believe that most of the funding to build these systems came from the US government. and the Bell systems to get these systems built as quickly as possible, It was indeed a HERCULEAN operation, especially in the frozen north! Many thanks for posting this video!
Back in the mid 70s, when I was working in Northern Ontario, I used to frequent a small town, in the middle of nowhere, called Armstrong (about 150 miles north of Thunder Bay), that had a USAF radar station, though it closed down shortly before my first visit there. However, there were a few other sites that were still active and I did some work in one in Falconbridge Ontario. They were part of the Pinetree line, which was the first radar line across the continent. I recall the circuits for the SAGE network, which connected the radar sites to some big computers, to keep track of enemy aircraft. The company I worked for was not part of Bell, though we often carried them into some remote communities.
Bell Long Lines were fun to talk on. Sometimes you could get some nice echoes due to multipathing.
There’s an old at&t Long Lines tower near Belton, Tx still standing. It’s now used by a wireless internet provider.
The diesel generator is a relic, that can be a sweet project for an enthusiast to restore, if it can be recovered from the site.
That setup looks to be mostly 1980's tech. The round "Bell Cells" in plastic racks is a dead giveaway, as well as the light blue racks themselves. In the 70's and earlier the cells were rectangular and sat on rubber mats on heavy steel racks, and the equipment racks were all "Telco Gray". The blue Bell System symbol on the wall is from the 70's and the AT&T logo is from the 80's.
Yes, you're exactly right. That's how I remember it back in the old central offices I've been in.
It's funny YT would recommend your channel to me today. I got to check out a very small, 80s AT&T built microwave repeater site yesterday and whats left of the AT&T equipment looked just like this! There was some DC stuff and a rack of channel banks and patch panels left and the (I believe) original Generac propane generator is still in use and works just fine.
Excellent video btw. Modern comm facilities are so boring in comparison to this stuff.
'Modern comm facilities are so boring" Right? Modern comm facilities are so Point-n-Click...
I wish I could show you some old C system analog carriers for open wire lines. They were built with vacuum tubes and date from the 1930s. They had something called a "Sensitrol relay" to measure the signal level and then operate a motor to crank the gain up or down. Depending on the model, they could carry 3 or 4 voice channels on a pair of wires. You often see open wire lines in old movies, particularly near railroads.
@james_Knott, Yes, my dad worked for the Bell System in the 60's, 70's and 80s. I've seen all of that old equipment including C carrier bays, but it was all retired in place. I was always fascinated with the old telephone facilities. Especially open wire. It's all gone now! I do miss it.
This is not a long lines site. The tower and equipment all indicate that it is simply a mid 90’s cell site. The land wasn’t even leased to AT&T until 1995, long after the breakup of the Bell System.
interesting stuff, keep making videos m8.
The long line system was also installed in Canada as well. You are talking about line-of-sight transmission and ionospheric propagation.
Wait! Does this mean the earth isn't flat?
I was told, after I hired in as a systems tech for SWBT, in 1999, that those big old batteries were the same batteries they use on submarines.
Even though I was a U.S. Navy submariner for 6 years, I can’t confirm that. Our batteries were hidden away in the battery compartment in the forward bottom part of the sub, which the interior communications (“IC men”) guys took care of. (I worked on ballistic missiles.)
They’ll definitely hold a charge for a while. They were full of clear sulfuric acid, and the containers were clear as well.
So when that site gets gutted out, that’ll be a big hazardous ⚠️ waste issue for them.
I am sure @ConnectionsMuseum would love to perhaps get their hands on some of this equipment so it can be preserved and perhaps used to set up a RF-hardline demo
Man I love this old stuff, it's so cool where we are today with technology and all but all this old stuff that got us here back then is awesome to understand. Who knows, one day we might have to power up that old robust stuff in the bomb proof shelters...
Many years ago, I worked on stuff that was older than I was!
That old C band network was 4/6 GHz. The network handled what ever the phone company did. While telephone and TV were certainly a large part of it, they also handled data, though not to the level of today. I recall working on the multiplexing equipment. Starting at the bottom was what was called "Voice Frequency Carrier Telegraphy" (VFCT) which connected the old teletype and similar circuits over a voice channel. Then the voice channels were grouped and carried over either microwave, open wire lines or the new fangled digital T1 system. In microwave the channels were bundled into groups and super groups, to be carried over the radio link. Back in those days, a modem, which might be as fast as 2400B, required a dedicated, conditioned circuit and when carried over microwave were not placed on channels near the edge of the group, as the filter roll off would reduce the bandwidth of the voice channel.
Also, those towers did not "broadcast". Broadcast is a specific term in telecom, which means from one point to many, as with radio broadcasts. Microwave links are point to point, with the signal focused on the other end. In fact, broadcast is one thing they did not want to do because a) it's a waste of signal and b) it might interfere with something else.
A lot of telecom gear is -48V and if you have 3 power supplies, you likely need only 2, with the 3rd for redundancy, in case of failure. You should be able to pull out 1, without affecting anything.
You say that equipment is old, but in fact looks fairly new. The stuff I used to work on was a lot older. For example, the batteries were in glass, not plastic.
It sounds like you're confusing hard line with wave guide. You had shown wave guide earlier then started talking about hard line. Hard line is essentially rigid coaxial cable, but those microwave sites usually used wave guide as even hard line coax had too much loss.
Anything with an 8 bit CPU is no older than 1974 or so.
That shelf you were leaning on, near the end, appears to be a DSX panel. where DS1 (T1) 1.544 Mb circuits were cross connected.
Being from KCMO I remember the AT&T building downtown that had the large microwave antennas on the top of the building. I wonder if that site talked directly to the site near me in Ks. Is there any maps on what towers were connected to what tower? There was a long lines site about 6-7 miles from my house. A number of years ago all the old microwave antennas were removed so now the site does not look so much like a long lines site. Would have been cool to see in the building. Probable been cleaned out now.
This site is much newer than the one I worked on. From the size of the wave guide the site used 3.6 to 4.2 Ghz microwave gear.
That would have handled one side of the connection. The other half would have been around 6 GHz.
IDK about the later generation of radios in this site but the older ones were give or take DS3 equivalent. That MPR in the mobility site can do a lot more than 5x that though it probably was licensed for some lower bitrate. Plus mobility configures their MPRs to be redundant, so instead of 6 individual EASV2 cards, the chassis is split primary and secondary so you really only have 3 pairs of EASV2 cards(or EAC10G etc) to allow fail over.
I can tell you that the Analog Video portion would have been36MHz each. That would have dropped down to a minimum of 6MHz when digital video modems came into play.
The really old sites would have been analog, with multiplexing to create groups and super groups. Later on, digital signal were used to modulate the microwave signal.
@@miketomas8564 As I recall, it took an entire DS3 to carry a broadcast quality TV signal.
@davewood406, Well Hi ! We meet again!
I really need one of these in my life
it really does look like you're sitting in a cabinet, nice job :)
If I'm not mistaken the battery do not not have sulfuric acid in them their nickel-iron batteries they are alkaline Bass or Edison batteries
I'm not sure, but I've seen identical batteries in a telephone exchange.
They were lead-acid.
For the most part the microwave and other transmission equipment is powered by lead acid cells. I’ve seen nickel-iron and other alkaline cells used as start batteries for the on-site diesel generators or turbines if the site has them, although sometimes they are the more standard automotive lead acid type.
This was awesome! Thank you for the video. Do you have any info on this site or why it is still intact?
Long lines were still around in the 90's. Just like party lines were still around in certain parts until around 2000
in nov im taking my 4x4 group to check out the long lines equipment bunker on razor rd near barstow ca. there is also a unmarked att microwave antenna close to anza borreigo. down town LA has an interesting building next to the Japanese embassy, similar to that spooky building in New York.
That old bunker was once a L3 carrier main repeater station near Baker, CA. Back in the 70's the PT&T com. techs called it Beacon underground. Unfortunately vandals broke into it and destroyed everything and stole all the copper! It makes me sick because I was down there once back in 1978 when it was still in operation.
My gods its beautiful
I admit I snorted when I heard “1 gigahurt”
Yeah, I also got the impression he knows a bit, but not a lot about this gear.
Yeah, you're right. It's gigahertz, named after Heinrich Hertz. Hertz means cycles per second.
great in depth explanations ! With the project being dead, very surprised everything was still in working order. Is this for preservation, or simply abandoned in place? I would have thought everything would be powered down except for required tower lighting circuits.
Thanks for sharing!
Pretty sure they were in operation until the late 80’s.
Yeah, definitely. This DR6 radio was installed in 1984 or '85. The last microwave system (digital) developed . Just to be shut down 10 years later!
This is really cool, i live 30 min away from Fayetteville, Ar. And was wondering where this location is. I know there is some old sites close to fort smith along i40.
Well I have a few of those cards, now I know I have pieces of an AT&T longlines installation
There are still a set of AT&T Long Lines towers still standing in a small city in Middle TN. There is a building below the towers. There's always a car there, so I am not sure what AT&T is using this building for, and why these towers have stayed there for so long. Doesn't seem to host any DSL c/o. and its not running any active antennas for cell data. Do you know where this is?
This is to help more people see this!
FYI:
AT&T created this nationwide System
Built in the 60s and used till the 90s
3 Ghz to 4.2 GHz
L4 cables buried ran to these sites as well
They carried phone and TV
The 100 foot satellite dishes in the 70s were hooked up and they are still in use today.
I have been in the LL sites and in the Teleport sites and seeing these dishes was a huge thrill every day.
6 Gig as well. late 40s they had some experimental routes going, 1951 they had a transcon microwave path NY to SF. A good bit of it was shut down in 92, replaced by fiber optics.
@@davewood406 I remember in 99,00the new fiber was being trenched along the highways.
I worked at a government facility and our data went slowly. I remember the morning the first fiber went online and the speed was so fast.
The copper was maxed out all the time and it went from 100% capacity to.0001 capacity in a matter of seconds.
It really changed the world
@@ocsrc If you're not familiar with DWDM and CWDM fiber tech, dig in. Just an upgrade at the equipment at the ends, as long as the existing fibers are in good shape, they can carry a lot more data.
@@davewood406 pre-99 in our area we had fiber run by the cable company between the major cities on poles, but when AT&T ran the new fiber, I was driving a lot back and forth 300 miles each way, and they trenched and buried 8 plastic conduits along the utility ROW where the old copper was, and they installed the flower pots. That was handled by a third party, then they ran the fiber and they only ran just one of the conduit and they built a new switching center underground where the two interstates interchange was.
They connected into the COs in the major metro areas, 6 cities in my state. Seeing the giant metal jacket L4 cables and the tiny fiber and the fact that it could carry hundreds of thousands the amount of data, it makes me wonder what we will have 50 years from now.
I remember when C-band first started and cell phones when only the phone company had them on the 30 MHz low band, and then 800 MHz commercial cell phones, and Ku band when it first came out and was experimental.
And now C-band is about to be retired from satellite service and transferred to cell phone use.
I have seen the laser communication used for satellites and I have seen it used from the ground station, even tracking the moving satellites.
The beam was only visible when you wore the special glasses to see laser light.
I just wonder if that will replace the fiber one day.
At least from metro area to metro area.
I still remember dial up at 300 baud
And the first fax machines
And the first gateways to dial in to the Internet.
Young people who have never known a Time without smartphones don't understand what it was like before the revolution.
It was peaceful and quiet but there was a lot of down time.
I sit at restaurants or in doctor offices and I think about what it was like waiting 20 or 30 minutes, just sitting doing nothing and how boring it was.
I really hope I live to see the brain implant to communicate with our digital devices. Just think turn off the master bedroom lights and Alexa will read our thoughts and turn them off.
And self driving cars, that we can just go to sleep and wake up 10 hours later and be at our destination.
It will change the world, again.
@@ocsrc I used to work for the telecommunications division of Canadian National Railway, which later merged with the same from Canadian Pacific. Our fibres went along the tracks.
Cool video.
The stuff in the racks looks awfully modern for 1950 ?
Yeah, I don't think there were many labels back then that said "1984". 🙂
I think that equipment was more modern than the 1970s.
SOME of the long line towers are still going today.
What kind of batteries are those? What technology?
I do believe they're a nickel-iron battery look up Edison batteries you can go down the rabbit hole of when exide battery purchased them and switch them all out to lead acid did the Edison battery last and definitely just drain out the electrolyte every 50 years
@@kurtzxcvb3481 Wow that is what I thought they look like. Those batteries last literally forever. Very cool.
@@kurtzxcvb3481 I saw a life expectancy chart tucked into a round cell stand when we removed some and I forget exactly but somewhere around 70 degrees they expected 100 years of service. Assuming proper maintenance of course. A warmer room diminished life quite a bit. Still better than the VRLA they use now though.
Very interesting there is one of these towers I can see from my home. Is there any of this equipment in a museum?
I’m gonna burst some bubbles and suggest that this was not a long lines site. Nothing in this site appears to be from any earlier than the mid 80s. The circuit breakers, the processors, etc. Even the tower structure.
There were some Long Lines sites built like this one after 1983 (post Bell System divestiture). Some still exist today, but instead of using analog or digital microwave radio to access or regenerate the network signal, they typically use fiber optic equipment.
AT&T dropped the Long Lines term after divestiture in 1984.
The fun thing with the waveguides is sizing everything for the frequency. Everything from the bends to the runs had to be sized correctly to a multiple of the wavelength or else you would cause reflections and destructive interference. So when racks and equipment needed to be placed in the room you had a relatively (for rack work) tight tolerance on where everything needs to sit. I don't know how AT&T did it when they were laying out these buildings, but often it was easier to get the racks in the general vicinity and not bolt them to the floor, or leave very oversized holes in the bottom plates of the rack. That way when doing final assembly and fit up of everything you were free to nudge the rack over, or put shims under them. Then after all the tests you would just torque everything down in place. Because it just always seemed to be the case that the tower or entry hole through the building was just constructed to 0.25-2 inches off from the plans and you had to compensate by moving everything else.
Never heard southern bell long lines.. Just att long lines. Typo or different system?
Strap in... Pre divestiture it was all one but there were business groups with separate responsibilities, so up until 1984 it was the Long Lines Division of AT&T. Though for some reason the Pacific Bell region, Long Lines was handled by Pacific Bell. Which as the RBOCs reorganized, merged and whatnot after Divestiture became Southwestern Bell(SBC then AT&T as it exists today) So that might be what tripped him up. I want to say Long Lines stayed part of what was left of Ma Bell at least for a while but you need a map for the Splits and mergers post Divestiture...
I'd hope someone could paint a clearer picture but they way it played out was a mess and easy to get things confused.
Well that makes sense, it's wild just how much history the bell system has. I love it all, and seeing this site powered up was insane.
AT&T Long Lines was the division of AT&T that connected all the regional phone companies. Never heard of SB or any other "long lines".
@@James_Knott There was a discussion about that a few months ago, the Pacific/Nevada Bell region specifically. it was the same network and whatnot but technically the folks handling the day to day operations were Pacific/Nevada Bell. It was still AT&T Long Lines. I didn't take from that discussion that PB operated it independently. Likely a distinction without a difference other than to the bean counters and lawyers. It may have been more or less than that but thats just how the discussion painted it.
@davewood406, Hi, we meet again! Yes you are exactly right in everything about the Bell System divestiture. Before 1/1/84 Pacific Telephone and Nevada Bell were the only Bell operating companies maintaining their toll facilities, the rest of the country was all AT&T Long Lines. On 1/1/84 my dad , who worked for PT&T, was suddenly working for AT&T! Nobody liked it! And PT&T became Pacific Bell and the term "Long Lines" was dropped. They put different colored tape and different colored signs all over the equipment rooms in the toll offices designating what belonged to AT&T or Pacific Bell ! It was crazy!
This was neat! For your role do you actually need to know math beyond arithmetic and be able to calculate things by hand? Or just an awareness of what the application is doing enough?
The 50s to 60s site would likely have been TD2 carrying L carrier. That is what we had in Alaska on the White Alice system.
L Carrier? Like L-BAND? 70MHz Modulation?
This site looks like it was also converted into a POP. The more modern equipment (channel banks), etc., are mostly from the post microwave era.
Cool to cool.
It was called RF Skip
What kind of keyway is on the front door lock?
Those engineers were on their A game
epic.