Exploring a 1 MILLION Watt FM Tower
ฝัง
- เผยแพร่เมื่อ 13 มิ.ย. 2024
- My Dad and I took a road trip to tour the 1 MW FM community tower in Crestwood, MO, serving the entire St. Louis metro area combining 10 FM radio signals into two antenna systems.
Special thanks to the Audacy engineers who allowed us to take a peek at their (very clean!) transmitter rooms and equipment!
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#Radio #Transmitter #Engineering
Contents:
00:00 - The Supertower
01:52 - Grounding and Guy-Wires
03:11 - Tower-scale cable management
04:13 - Transmitter Room
05:49 - 400A power and backup power
07:09 - 50kW Dummy load, switching, and 30kW water cooling!
09:16 - MARTI filter cans and cable loss
10:37 - In the basement - from 30 to 300 kW
12:47 - Giant coax with explosive arcing potential
14:00 - Tower safety: RF lockout
15:01 - Power, Aux services, Comms, and Lights
16:41 - One tower, many stories - วิทยาศาสตร์และเทคโนโลยี
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Your dad is a legend! You must be so proud of him!
WKRP 50K AM transmitter room:
th-cam.com/video/cTPzTG1Lx60/w-d-xo.html
are you proud of him?
There must have been hundreds of ppl putting the whole thing together?
Amazing shots like the one of the top of the tower with the moon and a bird flying across the picture.
Totally join. A good dad.
I am , thank you Dad.
Your dad is an excellent presenter. He made it easy for the non-broadcast engineer to understand by not using commonly used terms likee Line, STL, RPU, Vault, and Tenant. Once again thanks for the great videos.
Hell, he made it easy for a non-engineer to understand!
Dad is crazy smart! Thanks!
I am not an engineer but I am an electrician...Let me tell you, your dad does an amazing job of explaining how things work in real life...very practical without ever trying to seem smart. Just a lot of knowledge with an amazing ability to simply explain how things work.
How Thick of a insulating rubber sleeve Would that high-voltage need if it wasn't in a grounded vacuum sealed copper pipe?
It’s crazy how TV and radio TX’s have evolved. A once entire room, now just one air cooled rack with a bunch of small solid state amps can push quite a few KW, mindblowing compared to what it all was.
On behalf of us broadcast nerds, thanks for the production work and upload! Always fun to see.
I worked in telecommunications as a tech for 30 years and it is the same thing. Big buildings now are mostly empty space for long haul communications transport. The amount of equipment at the site where this bandwidth is distributed has grown with the increased throughput.
I startled out doing some tower work but nothing this big. The highest antenna I ever climbed was overseas and it was only 150M.
yes, equipment is getting smaller, but also the needed TX power is much smaller (for example when comparing analog TV and digital DVB-T TV).
Right, but the magic of the old days is gone.
Now I've watched the video, it's amazing.
Who ever gets to see all the work involved in engineering to get a radio tower signal? Makes me really appreciate my radio even more.
The history of broadcast radio (AM, FM, etc., plus the analog to digital transition) is really interesting... hopefully we can dive more into some of that in future videos!
@@GeerlingEngineering YES PLEASE!
I recently discovered that DAB (European digital audio broadcasting) uses a tiny amount of power in comparison to analogue. Local stations can get away with 4 watts to cover a city. By local I mean someone broadcasting from home with an antenna on their roof. Wow, just wow.
th-cam.com/video/YXzmfmEjS8g/w-d-xo.html
@@DJ-Daz freedab is a pirate dab mux in Ireland run by hackrf one chips and is run inside people's houses. It covers most of Dublin and Cork, and the Dublin mux covers parts of England!
edit:
I thought I should mention that it is dab+ but that doesn't make much difference in context of discussion, main difference is using a much better codec for encoding the audio streams (AAC)
@@GeerlingEngineering You do that! I became an "Electronics Junkie" after being born in 1958. My last year of high school was @ a Tech School learning Radio & TV Repair. I encourage you to become an Amateur Radio operator, an Electronics Engineer; not just walkie talkies but *80-meters & up*. (D.C. to Daylight) It's been a fantastic ride for me. You've got more toys at your disposal now than Santa Claus. Go for it. 🇺🇸 😎👍☕
@@memediatek I looked into it a few months ago, being a dance music DJ I would love to do something like broadcast and teach, then bring in new talent. All local. There are even grants to cover the cost of the gear and a little left over to keep you going for a month or two.
I'm halfway through the video and I just had to pause and leave a comment about how awesome this video is.
Same.
Oh lol exactly what I was about to say! So awesome!
That’s nuthin’ Johnny Fever had 50K watts of AM power at his disposal.
th-cam.com/video/FzgLeC54cqs/w-d-xo.html
Damn dude I was bout to make this same comment, but you did so I'll reply to you lol.
True that!!❤
Your dad is a wonderful engineer and a fantastic presenter of information. An absolute joy to hear. Thank you both.
As a telecom engineer I loved seeing all of this. Thanks to both you and your dad for this amazing walkthrough!
I remember when they started moving the stations in St. Louis to that tower. To say I was drooling is an understatement. Seeing all that Heliax and all that wiring is amazing. It was definitely an engineering masterpiece to get all of those stations on one tower. I know at least one Amateur Radio repeater has a remote receive site on there (I think the K9HAM repeater out of Alton). Your Dad definitely gave a fantastic explanation of how that all works. I was nodding my head on a lot of stuff he was taking about. Especially gain on the antennas. Power on FM systems is considered ERP (effective radiated power) which is a what is being pushed up the coax and then combined with the gain of the antenna system.
Thanks again to your Dad and you for putting this video together. I know I appreciated it.
Yes indeed it is ERP, it's likely correct too, unlike ham calculators for ERP on dipoles ect as structure and ground makes a big difference compared to the free space calculations, get up in the sky like this tower and it's 99.999% free space.
VK1NME
United Video built one of the original Cable TV systems in St. Louis. The city decided to outlaw all TV and C-band antennas, including at our head end, then they wanted to add a 'luxury tax' to all cable bills to cover the full operating costs for trash collection. Both kept lawyers busty for a while.
@UCsUF5s2GCuY6qt3lncY603g They were liberal morons. They lost. While this was happening, we go a request to bid on building a system in Chicago. It had a clause that people couldn't be disconnected for not paying their bills. That request went straight into the trash.
I used to listen to KMOX the big AM station in St. Louis back in the 1970's and 80's because of the Sports programming but even though I'm only about 100 miles away as the crow flies in Southern Illinois the signal would go to hell at certain times but would clear up late at night. KMOX was supposedly a 50,000 watt station but the signal from KOA in Denver would sometimes be stronger than the KMOX signal. I used to stay up late and listen to talk radio on the big AM stations across the country but now if I try to listen to AM radio at night it's just a bunch of static for the most part. What changed?
I worked at a 5 MW EIRP UHF TV station in Florida. Our antenna was at the top of the 1700 foot tower. We had a eight input FM antenna at the 1200 foot level and another TV station was added at around 1400 feet. This was in the Orlando market. We had five FM stations on the tower, and a Trunking radio system which predates affordable Cell service. There were also leased two way radios for things like the Forestry Service.
We had two microwave STL systems. One from or original transmitter site that was fed from a former CARS link when the station transitioned from local access cable TV to OTA. the second STL came from our new studio just North of Orlando. The Comark TV transmitter used three 65KW EEV Klystrons, and large rectangular waveguide after the Diplexer.
I moved and rebuilt a RCA TTU25B transmitter in 1990 that had been at our old transmitter site. It was then used on Ch 58 in Destin Florida. It was 25 KW Visual, and 12.5 KW maximum Aural. The Aural section was a modified FM Broadcast transmitter that tripled the output frequency before it went to the final amplifier. That transmitter was released from final test at RCA on the day that I was born. 😁
M first job as a Broadcast Engineer was in 1973, at a US Army radio and TV station, in Alaska. The TV station was on Channel eight, and monochrome but I managed to transmit our station ID in color with no color equipment just to prove what an idiot the Information Officer was.
The radio station was on 980KHz, and the only AM station that I ever saw that used a center tapped horizontal dioole antenna.
I was allowed to tour both the now closed VOA station at Bethany Ohio in 1969, and the WLW site with the legendary 500KW 700KHz transmitter.
The VOA station was being upgraded from the original Crosley transmitters to new transmitters. These used servos to auto tune each stage, so they were more agile than the original Crosley units. There were ten identical new 50 KW transmitters that could be paralleled and the huge East/West curtain antenna aimed towards Europe. A new control room for the site was being built as well. It was fed by microwave from Washington DC, and it was to be the secondary master control site in case the DC studios were down or were destroyed. This was in the days that the TV networks were fed by AT&T microwave links from city to city.
I later worked at Microdyne which supplied a lot of Microwave equipment to Cable TV and Broadcast stations.
I was repairing C-band sat equipment in the '90s in my shop. I built a C-band signal generator from a highly modified tunable down converter.
Love your comments. Guys like you were my mentors and fellow engineers!
@@radijoe Thank you. You didn't tell a good engineer what he could or couldn't do. You let them d the best for your facility as long as the cost wasn't excessive. I got my start by testing out of the US Army's three year Broadcast Engineering school in 1972. I was told that no one who hadn't taken the course had ever passed that test. I scored over 93% without any preparation. That was higher than anyone who had taken the course. I always enjoyed helping other techs and engineers, as well as learning from them. One of my last projects was the kU band communications system aboard the ISS. I also worked on a turnkey earth station for NOAA's LEO weather satellites that controlled and received weather images from space. Let me know if you want to chat, off of TH-cam. I can email the Geerling Engineering website to give you contact information.
Michael, thank you for sharing that info! I really enjoyed a tour of the VOA Bethany, Ohio site when I was a kid. Each year, my family would travel south from Michigan toward Florida for vacation. And I was fascinated at all the huge shortwave antennas at that site near I-75. We stopped one year and got a great tour. I still remember the fluorescent lightbulb lighting up without being plugged in due to the high RF in the room. The engineers were fantastic.
In the 70's and 80's, VOA got the signal from DC to Bethany over many microwave hops? It was all analog along the path, right? Wonder how many hops that made. Likely similar to the way network TV was passed along on the AT&T long line towers?
@@SeanCaldwellvo Yes, it was similar to the public AT&T system, but it was on a private network that carried mostly military traffic.
A friend of mine who died around 2000 had worked for AT&T in the early '60s. He was one of the people who had to jury rig the irst nationwide network feed the day that John Kennedy was shot. There were three main networks, and some smaller feeds. Some non networked stations had to use a TV Demod to pick up a competing station and rebroadcast it. It was never designed for that application, so the bandwidth suffered as separate systems were tied together without proper Video Distribution Amplifiers which were not common at that time. This caused impedance mismatches.
As far as the VOA site, I joked with the engineer, "Have you ever been tempted to put one of those 50KW transmitters on Ch19 and into the curtain antenna before yelling, "Hey, 18 wheeler, there's a Smokey on your tail!" He looked like he was going to faint!
The light bulb trick worked much better with the original Crosley transmitters. They were designed before TV, and they were poorly shielded. They had large glass doors, and no low pass filters. That is the main reason they were replaced. They were beautiful, Art Deco/Industrial styling with a green metalflake painted finish. I asked the contractor what was to be done with the old transmitters. He told me that they were to all be scrapped, then he sold me that I was nuts when I suggested sending one to the Smithsonian Museum.
Nice story. Have you or anyone ever expressed concerns regarding radio frequencies? How was your and your coworkers health?
Hi from Australia. I was a broadcast technical officer during the 70s and 80s. Retired (changed professions) just as solid state was taking over. Loved the walk through. I felt right at home.
Takes me back to being a kid when my grandfather was an engineer for a local station and would take me with him to their AM transmitter.
As a guy that volunteers to climb towers for ham radio sites, I don't really get to see broadcast FM stuff. That basement was awesome!
Definitely on the cleaner side of tower site installations. They maintain the place very well!
as someone who is closer to your dads age than you I really appreciated this video. I wish I would have had any dad to teach me about anything. I tried to make a huge effort to teach my daughter everything I learned as I never was fortunate enough to get a son. She turned out better than I could ever imagine. Anyway enough of a pity party, I loved this video, and we need more of dad.
Girls can do anything, it just took a long time to give them a chance.
Great tour Mr. Geerling. Radio engineering gets in your blood. I've been at it for over 45 years now and everyday is as exciting and unpredictable as the day before.
I agree. It is a lifelong affliction. Once you catch the technical bug, there is no cure....LOL.
Being a broadcast engineer.... this brought back good memories. Great job recording and editing. Thanks.
Your dad seems like a genuinely nice guy. Big kudos to him!
16:00 - As an IT guy, I can relate to that issue. People plugging in stuff to your UPS and ruining the battery up time! I had to start doing the same as that fiber installer did, place labels over the receptacles.
As an electrical engineer with 30 years in telecom operations and St. Louis resident who grew up listening to some of these stations, this was FASCINATING. The power logistics are similar to central office operations. Using nitrogen to keep water vapor out of cables to avoid shorts is also similar, only with higher stakes due to the voltages.
What a completely totally awesome video! You and your dad completely rock! I've read all about this tower and have always wanted an inside view of how it works and now you have satisfied this curiosity. Thanks so much for such an amazing video. This seems like such an amazing feat of engineering to be able to integrate so many stations on the same tower. And what a complex management and control system there is. Just wow! Thanks for an amazing video!
Early in the pandemic I spent an afternoon driving around St Louis to find all the major broadcast antennas and this was definitely the most impressive. Very cool to see what's going on inside. Thanks for the video!
I am a tower watcher when I travel. I find myself trying to figure out what services are on each tower. Eventually I look back at the road!
If I had a chance to do it all over again, but in the past, such as the 1950's and 60's, I can think of two paths of engineering that would have been awesome: 1) civil engineering: particularly the building of the interstate system throughout the US, especially through the west (something seriously romantic about it all), blasting tunnels through mountains, creating switchbacks, slicing through no-man's land...and 2) RF engineering: in the heyday of AM/FM, practicing and applying the art and science, and a little black magic, of RF design, construction, and troubleshooting.
I remember seeing this tower, and it was interesting that it was in the middle of a cemetery.
I remember when I used to live in Mehlville as a kid, and a friend and I visited that same cemetery. I thought it was super interesting that there was a gigantic tower in the middle, and I always wondered what it was for, but know I know! Pretty awesome, and greatly appreciated, especially considering K-SHEE was one of the stations I listened to a lot.
Thank you for sharing this with us!
I service and commission Eaton UPS systems, including the 9355 20 to 30kva units in the video. This video answered a ton of questions that I had as a service tech going into these buildings. From one tech geek to another, I salute you!
Really enjoyed this video. I worked on shipboard long range radar in the Navy, then airport surveillance radar, radar beacon, and automated radar terminal systems for the FAA for 33 years before retiring 18 years ago. Also enjoy all your videos Jeff! Live just North of you near Springfield, IL.
Wow, I feel like Neo waking up and realizing that reality as we know it is just made up of pipes and cables. All of different sizes mind you, carrying all the information, liquids and gases to maintain the illusion we all live in. And not only that, there are entities moving around in this beautiful dimension, making sure everything works. Respect to your father!
A fascinating series of insights into modern RF transmission. Large diameter coax with solid inner and outer cores. Never seen that before. Jeff's Dad is cool.
The first wireless telegram that was broadcast from England in the early 1900's to the USA used solid coaxial line for the transmission line. The first coaxial lines ever were actually solid and rarely used as they were big diameter expensive feed lines. Balanced feeder was used extensively due to it being cheap until flexible coaxial cable was invented for military use which soon made it's way into the civilian market.
Called hardline, some of the transmission lines looked like waveguides..
At 6:18 what is the grey oval object in the centre with hundreds of short grey wires sticking out of its perimeter?
@@gordonwelcher9598 It looks like a floor mop, just stood up against the wall. :D You're seeing the back side of it, with the wooden pole and universal joint. the grey "wires" are just the cotton fibers at the edge of the mop.
Many years ago I would get giggly showing off my little Radio Shack FM transmitter kit hooked up to 50 feet of rg-58 into a tuned homemade 1/4 wave GP antenna mounted 30ft off the ground with broom sticks duct taped together strapped to the chimney lol...Putting out 15mw of dirty RF delivering clean audio 2 miles out still makes me grin...This tower and broadcast station is super and other worldly!!! There are still a few really good stations here in eastern part of US and still fire up the sdr to see what kind of good music and other programming is live....Cheers to your pops for having such a cool job ❤
I got started on a Radio Shack kit too! was able to broadcast a few hundred yards around the house as a kid and I thought it was the coolest thing ever.
@@GeerlingEngineering absolutely! Christmas season is upon us and it's fun to drive by someone's house with RaspPi or similar control lighting system and a sign in front of the house "tune your FM to 88.9" or similar so you can sit in your car and listen to the music synced to the Christmas lights...man I love tech! Cheers!
It's impressive to see so much concentrated in such a little place. The radio I work for has a antenna on the Jhon hancock building in Boston. The radio room looks about the same but the antennas are all spreaded on the rooftop.
This is cool… dad and son with the same hobby… I love radios because my dad too, but he died when I was 16. So I continue by myself. Now have 45 and I still transmit like first time
Well done video! I enjoyed seeing various broadcast tower insides over the years and this one was one of the best since your dad shared so much about it. Thank you for putting the time into making the video!
Wow this is freaking awesome!!!!! Thanks some much for showing us around! I always wondered how it's done and what's inside such a building. Blows my mind how much different techniques are used.
Love this channel , seeing you share these experiences with your father is so special. Spending time with your father is so important. It reminds me how grateful I am that I have good relationship with my father and to take advantage of that to nerd out together like you and your dad do ! Keep it up Jeff ! Hope you are doing well!
One of the best videos I've seen on TH-cam in years... thank both so much.
So much useful info, I will be re-watching this one many times.
This was fascinating ! Thanks for letting us in.
So glad I came across this video. It answers so many questions I had about high power transmission. My mind is blown at the size of the coax in those FM transmitters!
Awesome!
Watchin' from Cambodia. Feel like I'm just behind you having a great tour of this awesome facility!
Thank you and you dad so much!
A Merry Christmas and abundantly blessed 2023!
That is so cool... So.. all those copper "pipes" are not being used as conduits for wires, but they are actually coax in their own right - So the exterior of ALL of those copper pipes were the ground for the signal on the internal conductor? I would love to see the inside of one of those 90 degree bends..
Really cool video Jeff, I've always been fascinated with communications and RF tech. Thanks
Great stuff, thank you for sharing! Your Dad explaining every step in detail is legendary!
What a great father and son, I wish we had more great people like this DUO!
Amazing and super super interesting!! Please do more of these. I love seeing how things work behind the scenes.
This is one of my all-time favorite videos. I've visited a few tower sites and even climbed a fairly tall tower, but nothing like the one in the video. Some of that coaxial hardline is just massive compared to what I've seen.
Fascinating tour and story. Great history, towards the end, where he detailed the changing technologies from copper, to T1 to fiber. I grew up in the copper era and remember when only a single station could operate from any given tower. I'd love to hear more from you and your Dad. Great video!
Wow amazing, Idk why youtube recommended me this video but im glad i watched it. Your dad is excellent presenter and knows his stuff really well, you asked really good questions and top notch editing
Incredible!! I knew this would be interesting but did not expect it to actually be one of my favorite videos on youtube, thank you!!!
Great video Jeff, was a pleasure watching you and your dad.
We used to pass the tower daily and we knew that it was the Y98 broadcast tower. I figured there was a few more there but WOW! not that much. I know that many a Amateur radio operator would love to have a antenna on a tower but that is just amazing. Enjoyed the video.
Here I am at the other end of the state proud of the 100kw FM station I work on. One day I hope to be all solid state Nautel one of these years.
Great video! I'm considering going into the RF Engineering field, so this was very interesting. Thanks to your dad for the awesome tour and to you for the excellent video. Just found your channel and I'm glad I did.
This is AMAZING. Well done. You and your dad should do a bunch of stuff.
Your Father really knows his stuff. Thanks for sharing this 🙏
This was my kind of video, very detailed, asked about all the stuff I wanted to ask about, and did not waste time on unnecessary production. Thank you
Thank you thank you thank you guys for showing me exactly what the station looks like.
I never in a 50 year span ever knew how intense and intercit a station is.
Amazing to me.
This was extremely interesting, for some reason broadcast radio tech was always fascinating for me, especially now that digital and computing augments the whole thing. If you have any similar content in mind for the future, don't hold back :) I think for most of us living outside the US a separate video about HD radio would be really interesting. Your dad is amazing by the way.
I would love to 'talk shop' with my Dad about HD Radio and its history (and maybe do some comparison to DAB+ over in the EU)!
Okay, you have officially and certifiably totally BOGGLED my mind with this. I spent many years working in large data centers, and the biggest of those were mere tinker-toy child's-play compared to this incredible radio technology. Who would have guessed?
I've lived in St. Louis most of my life, I never knew about this tower. I do remember that the KSHE tower & studio was on Watson, next to the 66 Drive In Theater.
your dad is awesome af. It would be so fun and funny to see your dad and my dad hang out and talk shop. Love it!
Awesome video!! I do communications for the FAA so seeing some of the same principles and equipment we use, used in other industries and applications is awesome! Definitely showing the coworkers this video tomorrow
What an amazing tour. Thank you!!
I'm not a radio/electronics/orwhatever engineer, but I would really guess that a LOT less was necessary for FM Transmitting. Even of THIS scale.
This really blew my mind. Technology never fails to amaze me !!
PS. That bottom single point for that entire tower, is something I SERIOUSLY didn't expect either. :D
Sooo cool! I'm in television broadcast, so cool to see high power fm
We didn't show it in this video, but there are a few low power TV stations, and the remnants of a full power TV station complete with quad-pump water cooling in the basement!
We're hoping to look at a TV tower soon, too...
Great job! This brings back a lot of memories. I was a transmitter at a combines FM/TV/microwave site back in the 1970's when everything was analog. Our TV transmitter fed a high gain antenna to get 5 million watt visual power and 1.25 million aural power. FM was side mounted near the top. Microwave reflectors at two levels pointing to the roof where the dishes were, one for studio to transmitter links (STL), the other for intercity-microwave to get network feed from a sister station in another city. Two-way antennas a couple hundres feet up for remote site pickup, and a 5 thousand watt AM station down the road about five miles. Everything monitored and controlled from the TV/FM site. It was a blast. Then computers came along and I jumped ship. Retired from the computer biz 27 years later. My how things have changed! Big thanks to you and your dad!!
I wish more stuff like this existed. It's fascinating to see how things work behind the curtain, and so many operations are shrouded in secrecy for "security" or "intellectual property." As if someone's asking, gee, I wonder how they do all of that, so I can make nefarious plans? They do it the same way everyone else does it - there's no secret sauce here, it's just applied physics. Why not let people enjoy seeing how it works?
That is to say, thank you -- the transparency is appreciated by the curious minds out here in the ether.
Dad never answered your question/comment about AM radio towers. As I recall, in AM the tower is the antenna, as the wavelength is huge (compared to FM), and the base bearing is usually a ceramic dielectric insulator rather than the grounded one here. So, an AM antenna is easy to pick out, it's just a bare tower with nothing bolted to the sides (and they are never as huge as this thing).
Ah yes, you caught that-he didn't really answer that part, but I'm trying to convince him to take me on a tour of an AM tower too, so we can compare it a bit-that setup is quite a bit different!
@@GeerlingEngineering Yes, the setup for AM is typically quite different. As d00dEEE mentioned the tower itself is the radiator and this causes a number of complications as it has high RF voltage impressed upon it. As he mentioned, this requires an insulator at the base in the common bottom fed design so that the RF is not shorted to ground. There are also several other considerations. For example, it requires some special arrangements to power the anti-collision lights. A special type of isolation transformer is typically used (Austin ring) that has a toroidal primary and secondary with wide spacing between them to cut down on capacitance. Chokes (low pass filters) in the lines feeding the lights can also be used. The tower cannot be directly grounded for lightning protection so some kind of spark gap or surge arrester must be used to divert the lighting to ground and a choke is sometimes added to try and keep the lightning pulse from backing up into the transmitter output. The radiating tower must work against a ground plane and typically this means burying a lot of copper wires in a radial pattern every few degrees for a distance of at least a quarter of a wavelength from the tower base. The net effect is to form a "virtual antenna" pointing down into the earth that is the "missing half" of a centre fed dipole antenna. Due to the high voltage on the mast the guy wires have to have insulators on them to isolate the mast voltages from ground. Careful thought must be given to the location of these insulators on the guy wires as if the conductive lengths of the guy wires are too electrically long they can form parasitic resonant elements at the transmitter frequency which will distort the antenna radiating pattern.
I am sure there are lot of other considerations involved. These are just what occurred to me off the top of my head based mostly on first principles. While I am an electronics engineer and thus generally familiar with many fields of electronic I am not an antenna expert so if there is an antenna expert in the crowd I'd appreciate corrections or additional information that I can learn from.
@@Vincent_Sullivan AM transmitters also have to be built on typically wet soil so the ground mesh can properly ground the tower
@@Vincent_Sullivan Some excellent observations-I know from asking my Dad all about it when they rebuilt the KMOX tower a decade or so, that pretty much everything you mentioned is spot on. Also why you won't see my Dad walk near a live AM tower ever like he walked up to the FM tower and touched it!
This is awesome to see! I just graduated as an electrical engineer and I took a class on communications systems just last semester. Super cool to see everything in the field!
This arrangement is quite common here in the UK, with 1 tower handling all the TV / FM radio services as well as cell phone and other linked networks for personal data and communication.
Yeah, it's a shame there aren't any videos of the insides of the buildings, except for Emley Moor and even then it's short and no talking.
Also, Lewis of Ringway Manchester is persistently ignoring me asking him if he can sort something out relating to this, for some reason.
I've now asked Jeff if he can come back to the UK and arrange to video the insides of some UK transmitter site buildings.
Antennas do NOT increase the amount of power coming out of them. My guess is the ERP (Effective Radiated Power) may be 1 megawatt, but the power out but is 3-to-6 db (250 to 500 kW). The antenna shapes the radiated RF field to present on a signal at the receiving antenna a signal which would be as strong as 1 megawatt. if the antenna had no "gain". The gain from the antenna comes from shaping the radiated power that would have gone straight up and "pushing" it out to the sided or in some other way "focusing" the radiated signal in the direction of the intended receiving antenna. Again, Antenna do NOT add power to the radiated signal. EVER.
Yes, that was annoying, but a MEGAWATT sounds a lot cooler than 250KW with 6 dB of gain for a million watts ERP..l
Agreed!
@@bobaloo2012 OK Hollywood, the image of a megawatt appears cooler. This is a technical channal. 50kW is 50kW, NOT A MEGAWATT. Images only count in your imagination, not in the real world. EVER!
Can you please do more content in this field. I would love to know more about the Digital rf signal part of things. The OB microwave thing was also very interesting to hear. It makes sense, I just always thought that they sent the signal to the studio and then to the tower.
Great work on this video guys! I've always loved listen to the 'old timers' tell what they know and stories from the past and Dad is clearly a great one to listen to!
This is right up my street! Love it
I love this. Shared it all over with my ham and STL nerd friends.
Also if they happen to be surprising those unused Agilent/HP power meters, let me know :)
Incredible! I'm interested in how the signals can be combined to have multiple transmitters on one antenna. That's well beyond my knowledge of radio.
That's a great question, and you'd have to ask my Dad about the technical details, but here's a good primer from Radio World: www.radioworld.com/news-and-business/a-primer-on-fm-combiners
The problem isn't combining the signals; a simple "T" can do that. The problem is keeping the power of one transmitter from messing up (yes, damaging it) the other. Simply put, you use a very sharp filter that allows your signal out, but blocks the others from getting in.
@@JamieStuff So basically brick wall band-pass filters that only allows the signal to have influence over it's very narrow range of frequencies?
That was awesome! I studied Electrical Engineering with a major on Communications, I've been working in the IT Industry for the past 11 years and unfortunately I haven't got the opportunity to work on antennas and towers, so I gotta say, I really get stoked watching this engineering masterpieces. Great video and thanks for digging out my passion for this technology
Check out the transmitter company GatesAir, one of the transmitters he showed. Great company with a factory in Illinois.
I wish i had the knowledge that your dad has. I've been fascinated by radio communications for years and earned my HAM tech working on general now. It still blows my mind trying to comprehend how we can shape energy and magnetism and transmit and receive it through space. Very nice presentation and learned much. Thank you.
Astonished you can walk around with such high power everywhere
The majority of the radiated energy is up on the tower, so as long as you're not climbing on it, it's a lot less dangerous. I wouldn't recommend sleeping right next to the tower though!
How did the drone survive?!
There's not high power everywhere. The high power is at the top of the tower and with radiation patterns off the antenna very little would radiate towards the ground it would be like a -30db drop at the base of the tower meaning that 30,000w of power is like 30w of power. All the rest of the equipment is shielded so the RF is contained, although I'm a bit suss on how good the shielding is on the dummy loads.
Edit: Also RF power drops off at a square rate to distance so that 30w of power directly under the tower would be even less by the time it gets to the ground.
The antenna is a multi-array type so basically, wideband dipoles stacked up vertically making the radiation shoot off perpendicular to the vertical plane. They look like squares at the top but they act like dipoles just the shape widebands them like a cage dipole.
What a brilliant video, please do so much more of this, I really enjoy all cooperation videos that you two do together 😍
At around 5:00, are the pipes filled with actual cables, or are the pipes themselves waveguides, as it is often done in high power HF?
And how do the pipes transition to the tower, since they are stiff and can’t move with the tower like the other wires do, that run to the tower?
Incredible video, please do so much more!!!
Good questions-I'll have to follow-up with my Dad (maybe in a part 2!).
Same question
@@GeerlingEngineering Oh I really have no problem watching a part 2 😇😁
Great story, as a 41 year old tech/telecom engineer , worked on digital data transmission, some FM stations when i was younger, this is great information and presentation. I worked at a 1.5KW FM radio station in Europe and didn't have any idea that high powers need this kind of setup which is mental.
Thanks for the informative walk through. Air gap Coax cable that look like large water pipes- love it.
I learnt radio but we never discussed how you can send multiple radio signals on the one antenna. I love the respect you show towards your dad and the respect he shows to you.
That was a great look at what's behind a tower. I wonder what the power bill is like. Also, I'm surprised the drone had no problem flying and filming so close to such a powerful source of RF.
That's what you get when the frequencies are totally different
@@jim9930 I thought he mentioned 1 MW total power
@@jim9930 Oh that's new to me. Thanks, I shall be back with more knowledge
@@anonymousarmadillo6589 RF induction will induce a voltage in a wire. That amount of power from that close a distance isn't trivial.
@@veryboringname. It's floating with respect to ground potential. So how would it have any potential difference between any two points on/in the drone?
Great video! Please do more of these. Hope everything will be ok for you Jeff! Lovely to see you two together. Great team :)
This was so interesting! Thank you! I already watched part 2, and I'm looking forward to the TV and AM videos.
Super tower and no mention of how tall it is? Or did I miss it?
Ah, completely forgot to mention, it's 1115' tall (about 340 meters. Pretty high up!
I love this insight into critical infrastructure.
Ummm, it's not critical. If it were, it would be heavily secured. It's just radio jockeys. Or, you might as well consider all infrastructures to be "critical".
@@NeverTalkToCops1 Hey now, getting those tunes to pipe comfortably into your car speakers at 7 a.m. on a Monday morning to get to work might be critical to some :)
This is so cool! I love you two geeking out! Your dad seems to be very knowledgeable! As a starting RF engineer your dad and you are an inspiration ^^ hope to see more of you ^^
This video is absolutly amazing! Loved the detailled explanation!
Love that combiner in the basement. Does all that ambient RF on the tower mess up the two-way radio guys' receivers who are also on the tower? Do they need to run cavities on their linefeed to keep from getting overwhelmed from the broadcast RF?
Cavities do provide filtering. Seeing as those systems do have a transmit and receive frequency you need the cavities to keep them isolated from one another. If you don't have the cavities then you have to separate the antenna either vertically or horizontally. One of the major types of cavities used as what is referred to as BpBr (bandpass band reject.)
Every service that receives or transmits should do studies to see what they should do. Having the high power FM sat the top and most receive antennas hundreds of feet below help. Downward radiation is not as much as you would think. But receiver systems often have filters for best performance.
too cool man ... but go on.... stick a pico w on it
Ha! It wouldn't surprise me if there's a Pi or two somewhere around that building. I did find a few bits of rack gear (especially over on the TV side of things, which we didn't explore in this video) that I'm more familiar with from the Ansible/IT side!
Fascinating. Your dad is awesome. Thank you.
That shot of the tower just adjacent to the Moon was * chefs kiss * .
It was a happy coincidence that the moon was positioned there.
Saying "puts out a million watts of RF" and "having 1MW of EIRP" are two quite different things. Sure it's effective radiated RF in certain directions is the same as if it were 1MW isotropic, but that does not make it 1MW of RF output. Just sayin. Loved the video regardless - always great to look around a production transmission facility. Dave Jones did a great facility walkthrough too; well worth a look.
The million watt number is just a bit catchier for a title ;) - and that was an editorial decision by me (Jeff) that my Dad was like 'well...' but understands it gets a little more attention.
But 300,000 watts of RF is no joke either-just a matter of a technicality!
@@GeerlingEngineering here here! BTW you're a lucky lad to have such a cool dad :) Thanks for sharing
This seems a little more complicated than my icecast/shoutcast server.
When you start getting 'fry-a-human' levels of RF involved... it does get a bit more complicated!
I would never imagine there is so much infrastructure going on under this antenna tower, even considering its massive scale.
Amazing video!
I learned so much from this. It answered some questions I didn’t know I had. Thank you and your dad for doing this. Fascinating.
Well now we know where all the copper goes.
Seems YOU don't know much.
The amount of copper used at that 1 facility is insignificant compared to the Multi-Millions of places stuck with using 2x amount of copper due to lower mains voltage distribution... a matter of 'pissin it up the wall' in the USA.
Great video however, there was just one thing that irritated me, you kept referring to this as a "Tower", but technically it is a Mast, a Tower is self-supporting and thus has no guy wires, and a structure with guy wires is called a Mast.
Correct. A tower is free standing, a mast needs support. However, colloquially the terms are interchangeable.
Technically correct, the best kind! But more often people seem to refer to towers as ground-standing transmission apparatus, versus masts that could be attached to a tower.
Great explanation of the setup.. I used to work at a radio station when I was younger and loved talking to the engineers and absorbing everything I could.. never got a chance to go out to the transmission site.
I’ve climbed a ton of towers but not one as serious as this one. Much respect! Definitely showing coworkers. Good job guys!
I've wanted a tour of one of these forever! Thank you so much for sharing
I know right where this tower is! I live 10 minutes away and can easily see if from my house. This is awesome!