If I touch this tower, I die
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- čas přidán 27. 05. 2024
- KMOX-AM is a 50kW clear channel station in St. Louis, MO; take a tower of the tower and transmitter site!
Special thanks to Audacy and KMOX-AM engineers for assisting us with this tower tour. Find KMOX online here: www.audacy.com/kmox
Support me on Patreon: / geerlingguy
Sponsor me on GitHub: github.com/sponsors/geerlingguy
Merch: redshirtjeff.com
Main Channel: / geerlingengineering
Contents:
00:00 - 50,000 Watts
00:23 - The tower is the antenna
04:12 - The ATU (Antenna Tuning Unit)
11:30 - Transmitter building
14:03 - PEP Station (EMP-proof)
15:28 - Transmitter building (and power distribution)
20:50 - Giant tower lights, and the !@&(* button
23:41 - Guy wires and a full-service restroom
25:31 - Transmitter room
37:43 - Backup studio and MREs
39:34 - A century of tools in the workshop
41:21 - Fried frogs and other tails - Věda a technologie
The fact that you can hear the radio station inside the building just based on how much energy is radiating off conductors is absolutely terrifying.
I actually don't understand how/why you can hear anything, at least anything that isn't an incomprehensible mess. Isn't the signal an AM signal, essentially at the 1.12 MHz carrier frequency? How does the signal get mechanically rectified/demodulated back into the audio range? Any radio engineers out there who can explain this?
@@PukkehFrom what I understand, that building is what makes the AM signal. I'm probably wrong.
@@DanTDMJace My point is the AM signal is too high in frequency to be audible. It needs to be demodulated first to bring it into the audio range. I'm wondering what makes that happen, and how.
@@Pukkehair is a kinda shitty medium so maybe something with that, or maybe it’s magnetic fields causing resonance
Yea this is fascinating and I need to know how this works!
I'm a radio amateur (KA3KAS), and for me this was the equivalent of a Cessna private pilot getting a tour of a 747. All the principles are the same, but the scale is several orders of magnitude larger. I'd be interested in how they calculated for optimal standing wave ratio (SWR) before building it. Hearing echoes of the broadcast through all that metal is spooky indeed! Your father is a very clear presenter.
I agree!!!
Hi, G1ZQC here in the U.K. I have played with 160m AM and tuned 1/2 waves versus grounplaned 1/4 wave aerials. Getting the optimal modulation in the AM envelope is an art, requiring a good ear whilst monitoring. All good educational fun.
73rd like 😎
So that's the weird background robotic-ish sounds we hear, that you call Broadcast Echos?
Back in the day when I was doing this, broadcast stations tuned the antenna equipment using an RF bridge. Now, one would use an antenna analyzer. For a non-directional station like this, you hook the RF bridge / antenna analyzer directly to the tower feed point and measure the impedance. You need to know the exact tower resistance to calculate how many amps of RF current must be fed to the tower to get the licensed power (P = I squared R). The base current ammeter in the video was showing ~27 amps. Given that the licensed power is 50,000 watts, they must have measured ~68 ohms radiation resistance with the RF bridge / antenna analyzer. (27 * 27 * 68 ~= 50,0000). I will say that sitting at the tower base with the RF bridge, plotting the Smith chart by hand, was a big project. Now I can push a button on my antenna analyzer and it will plot a Smith chart in a few seconds!
Anyway, those big coils and capacitors in the "doghouse" (ATU) are part of a Pi orT matching network that converts the 50 ohm coax from the transmitter building to the impedance of the tower. When designing the ATU, one starts with the 50+j0 impedance of the feedline from the transmitter building, and calculates the component values necessary to match to the tower impedance. Usually the network is made using tapped coils and vacuum variable capacitors, so after setting the rough values to the calculated values, one connects the RF bridge / antenna analyzer to the input of the ATU, where the feedline would connect, and tweaks the values to get exactly 50+j0.
The important thing is that broadcast stations put the ATU right at the tower base, not back at the transmitter, so the 50 ohm coax is well matched to the antenna and has negligible standing waves.
For directional arrays, it's a lot more complicated, because the base impedance of the tower depends on the adjustment of the array. But again, there is an ATU at the tower base which matches that towers array impedance to the 50 ohm coax to minimize standing waves on the line. At the transmitter building (usually), there is a power dividing network, called a phasor, which has a 50 ohm input from the transmitter, and a separate 50 ohm output to drive the coax to each tower. The phasor divides the power according to the ratios and phases needed to generate the licensed directional pattern.
Stations often have a daytime directional pattern and a nighttime pattern. At the base of each tower, they often have separate tuning networks for each pattern, and big RF contactors, just like the one which was used to ground the tower in this video, are used to switch between tuning networks. I worked at a station which was non-directional, using the center tower, in the daytime, and directional with a 3-tower array at night. At the base of the center tower, there were 2 Pi tuning networks, one for day and one for night. At 2 end towers, there was a single Pi tuning network which was always connected to the coax, but a big RF contactor switched the tower feed point from the output of the Pi network (night), or to a "detuning" network (day). The detuning network made the tower "invisible" at the station's frequency so the the end towers did not act as parasitic director elements, basically a beam, which would have generated an oblong pattern rather than the desired circular, non-directional pattern. They talked a little about this when he said they had to make the main tower "disappear" when operating on the backup tower.
The last thing I'll mention is the Austin Ring transformer, which sends AC power to the tower lights without shorting out the RF. It is basically a toroidal transformer. The primary is wound directly on the core. This is the lower ring, the primary and the core. The secondary is the upper ring. It doesn't matter how much space there is between the secondary winding and the core, so long as the winding passes through the core. It is called an Austin transformer, because Austin is the name of the company who originally manufactured them.
--de N3TS
Please Jeff, never forget what these videos are about: you and your dad. My father was in charge of the technical part of electricity for the entire city of Amsterdam, and a complete nerd. He is the reason I "play" with Raspberry Pi these days. Unfortunately, he passed away at far too early an age, so I can no longer share my tinkering with him. So again, computers are fun, fathers are more important .
@@ntfx_org7603maybe 100 years ago , but i can pretty much guarantee that’s not the case. Also, kinda an odd placement choice for your comment. Regardless hope everyone is having a pleasant day. Take care.
@@ntfx_org7603 I think a deep sea divers lifespan is shorter than 55. Also electrical power workers on power lines differ from what radio engineers are doing. It is easier to shut down the power feed to a radio antenna.
Yeah, my dad loves tech
but, now, also immortal
mooi! dat soort verhalen proberen we vast te leggen bij BOEi! twee jaar geleden iets van over de PNEM mogen maken. Waar zat je vader?
Your father is a rare breed, someone who has a wealth of information in his head and is able to explain it in a way that people can understand it. Thanks for sharing these videos, subscribed & hope to see more.
Not really..its just his specialty , to him its all.easy cuz that's his life..Same as being a Dentist dentist understand everything bout teeth etc .N GENRAL Dr knows stuff bout health but got no specialty. I bet you if you were to have him diagnose electric problems in a car he be not that Good, he'd have knowledge but not like in his specialty...
“If you can’t explain it to a six-year-old, then you don’t understand it yourself” - Albert Einstein
same - very well done. I'm blessed because i love this subject matter so much, as well as old steam engines and water turbine (gridding them - getting them phased to match the frequency of the line they help drive is so amazing - i've put in equipment in coal/nuclear power plants and have seen them bring up a generator/turbine into phase lock - 1000 megawatt. i love this so much!)
@@itsmisterchrisThat is entirely besides the point. Someone can be smart and be a crap teacher. Someone can be a good teacher but only surface level still. I get asked a lot to explain and get told that I'm a better teacher than their middle school one was but at the same time I envy people who are this deep into the knowledge of their profession. Maybe I can get there some day
Very very intelligent man
Please don't touch the tower. I actually like your content.
Darwin’s theory of natural selection.
Touch my monkey
It would only hurt for a little while but the smell would be horrific.
imagine touching the tower and getting never gunna give you up played by your skin as it burns
I'd lick it
The single turn loop in the tower RF feedline is a lightning choke (not to be confused with a lighting choke). It's purpose is to prevent energy from a lightning strike from entering, and damaging, the antenna tuning unit. The loop presents a small amount of inductance that retards the initial current pulse of the lightning, diverting that energy to the ball gap, where it flows harmlessly into the ground. The added bit of inductive reactance presented to the RF by the lightning choke is nulled out during final ATU tuning.
I (Jeff) don't know more than like 0.00001% of all there is to know about antennas and RF... but it sounds like this is a plausible reason for that loop!
My Dad mentioned that some parts of the AM signal path were managed by consultants who (these are not his words, they're mine) knew the dark arts of properly tuning AM towers for maximum efficiency.
He knows a lot more on the side leading up to the ATU, but I think he was primarily FM for half his career, so learned a lot at KMOX! (Always keep learning... you never know much except what you don't know)
how the hell do people figure this stuff out?!? it's nuts!
@@mcpr5971 Engineering Biatch..!
Yep, exactly. The rise time encountered during a lightning strike is so quick that it cannot travel around that loop before being directed back to the path of least resistance (ball gap) for that tremendous amount of electrical energy, so that MOST of it is conducted to ground.
@@GeerlingEngineering If you think that's the dark art of engineering, imagine creating and maintaining a 5 or 8 or 10 tower phased array with day and night patterns! All of those from the 1930s or 1940s done in the engineers' heads.
I worked at an HF transmitter site when I was in the Army. We had multiple 1kW to 70kW transmitters, about 17 Rhombic antennas, backup power generation, technical control facilities, workshops, etc. Your video brought back a lot of good memories! Thanks for all the work to put this together and share it.
As a retired design engineer who worked predominantly with digital circuits, I always looked on RF as a bit of a black-art. What this has shown me is that high-power RF is in a league of its own. I loved that modular high-efficiency AM transmitter cabinet - I had no idea it was done like that these days. All the shiny copper was nice too. The whole video was truly fascinating. Thank you. both, for taking the time and sharing this knowledge.
More! More! More! I could watch these tours endlessly. They're beyond fascinating. Kudos to you and your Dad! And agreed about the Simpson 260. At Memphis in Navy Tradevman "A" School in the mid-60's, every bench position had a 260. They're still unbeatable.
They have been around a long time!!!
Although mine lost the battle raising 4 kids! But a few drops were my fault…
Agreed an excellent tour and so informative. His dad was a bit confused on that Simpson he pulled off the bench. That's a model 303 VTVM. Easily identified by the two rotary switches on the front and the two circular connectors for the separate AC/Ohms and DC probes. Easy mistake as both the 260 and 303 series have identical case sizes. Enjoyed the tour so much - thanks :)
Bet he's also got a Weller 8200!!!!
Some of my most prized possessions are the Simpsons I got from my BE mentor. Same as the Bird meters. Like a master machinist handing down his calipers.
Love these episodes with your dad nerding away like crazy.. 😂 Please keep on making them. Awesome to listen to the incredible knowledge and how he breathes RF!
literal porn.
I’m seconding this. I love these episodes.
I always found interesting how as you increase frequency, the electricity goes from travelling in wires to travelling in pipes, and then as you increase even more into UHF and microwave it starts looking like HVAC ducts.
Skin effect
Wave Guide en.wikipedia.org/wiki/Waveguide
I used to see a lot of ducts in radar technology =)
Almost 50 years ago, I worked for a 3 tower AM station. Periodically I had to go out to each tower to take base-current readings. I think I remember the hair on my arms standing straight up because of all the power in the dog house. We had to take the readings when there was no modulation, so we had a little transistor radio… but it didn’t have to be set to the station frequency. It was so powerful in there, you could set it to any frequency and you’d hear it. I was just a kid of 20 with almost no training. Lucky I didn’t touch anything that would have killed me.
An electrician at my work said when he was starting out he worked at an old coal preparation plant and said their electrician sent him into the control room where all the panels and electrical buses were located and he said as soon as he walked in the hairs stood up on end and the further he went in he started feeling like he was being stung by a bee. Those old transistors, inverters and relays were electrifying the air. Thankfully with todays solid state drives and better insulation I don’t have to deal that in my coal plant’s control room
I had no idea how complicated these transmitter towers are. What a great idea for a video. Your dad is a natural in front of the camera. He knows his stuff and explains it really well.
When I was a kid (1950s) my neighbor was a transmitter engineer at WSB in Atlanta. He would take me to the transmitter sight sometimes. The transmitter was an old Western Electric 50 KW thing that took up the entire building. The final tubes were about 5 feet high. I was about 3 feet and a half. I was very impressed. He was Ed Perry and helped me build my first crystal radio. Thanks Ed. (Rob KM4OXf)
I never got to see the original Westinghouse transmitter, only saw pictures, but those things were massive (and impressive!).
That's a well credentialed Elmer.
Always fascinating to us Radio Nerd-Geeks! Why? No clue. Just is. LOL
Are you saying there are vacuum tubes that are five feet tall?
As a 1830s kid i can understand
I love this. I've had a Simpson 260 for some 60+ years and I don't think I could live without it. Even with modern stuff that costs a bundle, the 260 is really the most valuable piece of test equipment I've ever had. A little plus is the mirrored scale, which for us old old old timers helps us with our eyesight.
The Simpson 260 is a must for telephone techs. A old timer trained me on how to test the outside lines with an analog meter.
Great meter. Don't drop it on a cement floor.
Your dad seems like a cool guy, you're so lucky you can still have that experience with your pops. Don't take it for granted. Great video too, love the transmitter sites. I once worked at place that had satellite transmitters and some things are similar.
I'm a BS Electrical Engineer and PE, and this video validates my opinion that RF power electronics is black magic and the guys that maintain it are wizards.
Seriously though, very very cool stuff!
Agreed 🧙♂️
.... Yeah, what he said.... RF is Voodoo and the people good at it are wizards.
I'm a Structural Engineer and PE, and I've engineered many a guyed tower, even 1 AM tower just like that in this video. I definitely leave all the RF stuff up to the RF folks. The spec sheets and diagrams and equipment they are constantly dealing with all flies right over my head; just tell me how big it is, how much it weights, and if it has some other special requirement, and I'll handle all the seismic, wind and ice loads for you.
Given that the numnut at my local Mickie D's is making $17/hr, asking me "do you want fries with that", Mr. Geerling and the like should be making 20x that! Seriously.
@@markb978idiot
I am a contract broadcast engineer and know all this but somehow watch the whole video because it's really cool to see how other guys do the same things.
When growing up in Florissant, my Grandfather would have his little portable radio playing KMOX with him either in the house, out working in his workshop, or just siting out on the front porch. On a clear night I can get KMOX 800 miles away in Charlotte, NC.
I am an Amateur Radio Op as well (W4KDN) and was privileged to experience a VIP tour of the Trans World Radio site on the island of Bonaire (about 50 miles off the coast of Venezuela). TWR runs 440 KW into a 4 tower directional and steerable array. I authored an article and submitted it to QST which was published. This video brought back some not too distant memories of that tour.
Nice tour!
Re the Xilinx chips: I designed hardware at Nautel for a while, and we used FPGAs in all sorts of places on both the AM and FM product lines. We didn't use them because of a lack of volume to justify rolling an ASIC, we used them because they kick ass.
FPGAs are absolute monsters at doing real-time DSP calculations, which is what you need for modern radio broadcast transmitter technology, especially since HD Radio came on the scene. Modern FPGA chips have hundreds, even thousands of DSP slices with tightly coupled memory which can run at hundreds of MHz. Comparing a classic DSP chip to a FPGA is like comparing a CPU to a GPU - the latter is a lot harder to program for and not suitable for a lot of tasks, but for certain tasks can absolutely mop the floor with the former.
In the exciter board in our FM transmitters, the main DSP chip sends a digital baseband over to the FPGA at a couple megasamples/sec - the FPGA then upsamples this to a much higher processing rate, applies a bunch of voodoo to linearize and improve the energy efficiency of the transmitter, frequency shifts the baseband with a DDS to set the transmit frequency, and outputs the resulting high speed data stream to a high speed RF DAC that generates the main RF signal for the transmitter. Simultaneously, the same FPGA captures samples from a high speed ADC which is sniffing the RF output of the transmitter, this gets used for the adaptive linearization voodoo and a few other things.
In terms of raw calculations, the FPGA ends up doing easily 1000x the amount of DSP calculations that the actual DSP chip on the board does.
Now... I want to go to Gates or some other manufacturer and talk to their engineers. Fascinating!
I've got contacts at Nautel, and Elenos/BE to a lesser extent, and might be able to arrange something.
Hi, can you share which programming languages did you use to run FM multiplex to RF pipeline inside the exciter? I understand there had to be either Verilog or VHDL for FPGA I wonder what was used for microcontrollers running the whole thing. Which language the predistortion engine is written?
@@antronx7 I can't share that information.
@@garymarsh23well you could, but then you’d have to kill him ….😉
This video was recommended. I originally thought I would watch a few minutes and move on, BUT I really really enjoyed the video. Yall kept it interesting and humorous. Thank you for the inside view of KMOX and your history. Why does every business have a space where chairs go to die but never quite make it to the dumpster. Subbed and thumbed.
Haha I know what you mean. I think every business with more than a few employees ends up with one of those chair graveyards!
I wonder if every current KMOX employee got one chair each. Would there still be pile of chairs? LOL Have a great day. Do not touch the tower..@@GeerlingEngineering
I've listened to KMOX since the early 70's. Strongest distant station (about 35-40 miles) I can get. We have a local station, but its only about 10 miles away.
This brought back memories, my Grandfather was a radio engineer and ran the tower at KOKH 25 UHF when I was a kid. He used to let me push the button that signed the station on and off. Excellent video. Got me into working to get my amateur radio license, just like he had. ( W5JYT) Very informative and comprehensive video. Please do more!
I've been an AM radio DX'er for years. When I was younger, KMOX was the first DX I ever picked up back in the early 90's, on my little GPX stereo. I've been hooked ever since. Now I have radios galore and 25 years worth of good DX contacts. I live up in Wisconsin, just north of Chicago. Late at night, 1-2AM, I can pick up NYC, and Los Angeles, Dallas, Denver, Winnipeg, Toronto, Montreal, Nashville. Basically if the conditions are good, I can pick up almost the entire US. Getting anything from west of the rockies is difficult though
Pesky mountains!
Here in Michigan KMOX sounds like a local after sunset most of the time. Love those clear channel 50K stations!!!!
1130AM KWKH, a local 50K station, was able to be heard all over the country back in the day. They had the Louisiana Hayride where Elvis debuted as well as countless other stars. You know that saying "ELVIS HAS LEFT THE BUILDING!"? The first time it was said was here at the Hayride. All the fans were staying there, waiting on Elvis to come back out so they finally had to tell the fans Elvis was gone so they'd leave! 🤣
Hey neighbor LOL... Mike M Wausau / Merrill Area....
KMOX was my first-ever AM DX station as well. I was about 5 or 6 years old in suburban Montreal, Canada, listening under the covers on a really good transistor radio. My teachers in grade school were amazed how I knew what the weather was in St. Louis, that there were tornados overnight, and similar tidbits of knowledge from the eastern half of the US, as I listened to WWRL, WSB, KDKA, and the rest of the 50kW blowtorches.
Thanks for the tour.
Just imagine putting that lot at 50kw and more, on board a Ship. As was done in the 60s and 70s on the Radio Ships that served AM to the U.K. and the continent of Europe.
Radio Caroline, Radio North sea International, Radio City, Radio London. The true pioneers of UK local radio.
Radio Caroline still exist today, but licenced on land 4KW on 648kHz at Orford Ness in the South East of England. They run the transmitter on Solar power during the daylight.
Look them up, well worth a visit, and they still have the last Radio Ship, fully kitted out, but connected to the TX site via the internet. Yes they still broadcast from the Ship once a month.
I was a radio operator in the military '85-'95. Radio/Radioteletype SSB AM.
We used a 15' whip antenna (xmitting about 10k volts RF) on the vehicle for mobile use, but when
we set up we raised a 50 ohm doublet (cut to whatever freq we were assigned). While deployed during the
first Gulf war, we had to set up during a sandstorm. Once the antenna
was raised, I picked up the end of the coax nearest the truck to
connect it. Big mistake. The static that had built up from the
blowing sand was enough to knock the ever-lovin fool outta me.
My whole body jolted and it felt like someone smacked the bottom
of my heels with a sledgehammer. The connector literally arced to
the grounded equipment when we went to connect it.
I was the AM transmitter RFTech for WJJZ 1460 Kc. It was my job to monitor the Dog House on an island in the Delaware River. I worked alone 3 Fay’s a week Friday to Sunday 12 hour days. Ours was a 5 kilowatt station. I arouse at four AM and drove to the Marina, then took an outboard motor boat around the cove to our landing. It was a lonely boring job requiring an FCC 1st Class Radiotelephone license. The hourly pay was good, but no benefits or vacation. I left that job for a much better gig with RCA building in the space program. They asked me to change the lights on top of the antenna in the dark. I refused, I was fired! It was always my goal to work in broadcasting , radio and or TV. This job cured me fast!
Being able to hear the broadcast when transmitter arcs is very cool
Yeah weird. Reminds me of when Laurie Partridge was hearing radio on her braces 😂
Man I love this video 10/10. It was so informative. I learned so much about am radio towers. All I knew before was they were energized and the wavelengths were impractically huge.
I chuckled at 950mhz studio link antenna called microwave rather than UHF. Its right but its just so strange as someone who worked with 900mhz to 60ghz. We just called everything sub 1ghz UHF.
I mean compared to AM, almost anything is microwave :D
@@GeerlingEngineering So true.
For other viewers here's some comparisons in the wavelength size.
49965.4096666667km wavelength @ 6hz (Teslas wireless power system)
555 meters wavelength @ 0.540mhz (start of AM broadcast band)
176 meters @ 1.7mhz (end of AM broadcast band)
11 meters @ 27mhz (CB radio)
5.99 meters @ 50mhz (6 meter ham band)
2.8 meters @ 107mhz (end of FM band)
2 meters @ 147mhz (2 meter ham band)
68cm @ 440mhz (UHF ham band)
54cm @ 550mhz (best UHF television band)
42cm @ 700mhz (cellular 700mhz band)
32cm @915mhz (ism 900mhz uhf band)
12cm @2412mhz ( wifi)
8cm @ 3.655ghz (Wireless Broadband Services WBS band for licensed fixed wireless)
5cm @ 5830mhz (end of 5ghz uni3 wifi)
1.2cm @ 24ghz (unlicensed 24ghz band)
4mm @ 60ghz (unlicensed 60ghz band)
3mm @ 90ghz (upper band mmwave 5g)
0.9mm @ 300ghz (right before it becomes infrared)
Its truly an amazing thing that people were ever able to figure out that radio waves, heat and light were the same thing before microwave spectrum and radar was a thing.
My dad worked for two-way radio, zipcall, metromedia paging in the Boston area. When I was younger in the 60s I would go with him on many of his service calls. This video brings back many good memories during that time period. One of his contracts was with WBZ TV, but he also serviced the US Navy, the Coast Guard (Nantucket Light), Woods Hole, etc. He had a fascinating life, and always had great stories.
I remember him telling me that he had to service a transmitter on Mt. Wachusett. He didn't know at the time the transmitter tower itself was live. He grabbed the tower and was thrown back. One of the guys he worked with laughed and told him he had to jump onto the tower in order to climb it.
At another time the Navy sent him out to service the radio equipment on a tugboat. When he got to the boat location, he called and told the Navy that he couldn't service the boat. When asked why, he said the boat had sunk at the dock. They had to raise the boat before he could service the equipment.
He was literally in love with his job. Miss you dad. RIP. ❤
it always amazes me how far away from STL I can hear KMOX. This was super cool to see, thanks for sharing.
A big thank you to your dad and you for recording this, it was super interesting!
I love this. I always wanted to know about AM towers. you are a fantastic creator!
Wow! I lived in St. Louis in the ‘90s for 5 years and listened to KMOX. I moved to Peoria, IL, and went to work for ROHN designing antenna towers. One of the differences is I spotted is that we would design provide a 3’ high base pedistal which is higher than KMOX’s. The reason was to keep the weeds from touching the base insulator and reduce the varmits from getting on the tower and causing an outage. I recognized a lot of the tower and, guy hardware and lights we would sell.
In another life I was in the electrical world and delt with varmit control in electrical substations. I had to stop squirrels from climbing on the circuit breakers and cutting power to the Texas Medical Center. I designed a squirrel proof fence. Today they have electric barriers in their substations to keep the varmits off the high voltage equipment.
I totally enjoyed the video because I have never had the cooks tour of an AM radio station, much less than one I used to listen to.
My dad lived next to a TV antenna. I said to him one day that he could probably watch TV without having it plugged in the wall socket. He said, " Son, you can colse your eyes and see the programs on the inside of your eyelids !"
I loved my dad , he was the best .
I saw one of those Buss Fuses displays at, coincidentally, the bus workshop my dad worked at. So when I was a little kid I thought that meant the fuses were designed for busses. And since cars are smaller than buses, using a buss fuse on a car would give it extra reliability.
Haha "Dad why do they always misspell 'bus'?"
It's good to see things like this, which I was used to seeing when I accompanied my father, working for Portuguese Broadcasting. It was and continues to be a very special world. Thank you for making these images available and thank you also for the comments throughout the video, absolutely crucial for anyone interested in this technical area.
Stay safe!
Macedo Pinto, Portugal
At around 10 minutes, you can hear the broadcast coming from an electrical arc??? Mind blown!
(FCC First Class Radiotelephone licensed since April 12, 1970 - I am licensed to operate and maintain transmitters like this one. Former WA6TDG amateur radio operator before that. Worked with 100W power line carrier - around 200 kHz - quite a lot before retiring from a Fortune 100 electric company five years ago.)
If you touch the tower you probably won't die right away, but you sure won't like it either. In the AM broadcast band touching the energized vertical would be spectacularly unpleasant - RF burns are not something anybody likes because they run deep and don't heal well.
Thanks for sharing. My dad (he’s just turned 99!) had an older friend who was a radio engineer. Always interesting, and always ready to share his love of science and technology with anyone who wanted to learn. Your dad reminds me of him.
Your dad’s knowledge is amazing! As an amateur radio operator being able to see this is incredibly fascinating! Thank you so much for sharing!
Amazing stuff. Raises my appreciation for AM station operation. Of course, nowadays there's at least one generation that's never listened to AM radio.
I'm from Mexico and when I was a kid when i heard an AM radio station in English after midnight I was very surprised and then my mom said that she also heard it when she was a kid. Thank you for this awesome and informative video
What a great video!
I've spent many nights listening to the ballgame with my grandparents thanks to this KMOX tower.
73
I always remember listening to the Blues and Cards driving home at night as a storm was approaching. You could always tell when it was getting near by how loud and frequent the crackles in the signal were!
This takes me back to my teenage years. One of my scout leaders growing up was a broadcast engineer (Pete at MidAmerica. Your father will know him, I'm sure.) I worked for him a little after high school and we went to a bunch of xmitter sites. He sounds very similar to your dad. I watched him wind coils, service xmitters, all sorts of stuff. Later, I worked with him on my master's thesis of automating the measurement of AM tower patterns. good times.
A late friend of mine was station engineer of AM station WEMP & what he told me of operation of a am radio station is exactly how you describe it. Thanks for posting this very informative video.
That meter is too cool. I recognized it immediately. In 1980, I learned DC theory in high school. The 260 Simpson is the meter we used.
Nice to see how AM radio is still very elaborately run and clearly not going anywhere anytime soon. Great content, thanks KMOX for the tour.
These tours with your dad are great! Very cool to see these sites and the changes that have occurred over the years. Many of us hams get excited about our 100W transceivers and maybe a 1500W amp but these stations are the real deal. Keep up the good work!
I get nervous with my little 5W transceiver haha
My Dad's used to high power... I just remember how much a little 120v shock hurt, and my Dad described RF burns and made me want to give anything in a transmission line a wide berth.
It's truly interesting to have an expert show you around their work site. You see a lot of things that wouldn't be on the official tour.
What a lovely video. Many thanks to you and Dad. A beautiful experience. I've been FCC-licensed since 1971 -- it's always a pleasure to experience the excellent engineering and construction of these magnificent high-power installations.
I love that there's a breaker box right through the wall from the shower.
Just a good prep for what happens if you get too close to the tower!
high power is both fascinating and scary
It just requires a lot more respect!!!!!
Yes, I'm scared of my higher power too
Yes, I'm scared of my higher power too
Where electronics & plumbing collide! Great video. The company for which I work has many such masts - the most complex of which has six services on the same tower.... now that's one very complex ATU or ACU as we call them in New Zealand. Thank you for the tour.
Great video. I wish everyone had the ability to see the inside of the station and the explanation like a few of us have. It's always a time that we wish we could have it on tape for later.
For the blueprints, you can capture them using a tripod, DSLR, and flash. Most modern DSLRs have enough pixels to meet or exceed 150 dpi depending on the lens. To get it flat you can use glass... or bricks. I always check for KMOX when I turn on the AM radio at night, and I always hear it several states away. 73 and thanks for the video.!
A.M. antenna systems are very interesting. Thank you to your father and you for this awesome video!
Do you mean AM (amplitude modulation), or Medium Wave (0.5 to 1.5 mhz)? We use the terms interchangeably for broadcast radio, but they each speak to different things. For example, the entire mast being the antenna is because it's medium wave, and would apply regardless of the modulation. Meanwhile hearing echoes of the transmission are because it's AM, and would happen regardless of the frequency.
I guess my point is that I wish the video made these differences a little more explicit.
Fantastic video. As a ham radio guy who's also been listening to KMOX since I was very young, this was a very interesting video! It's really neat to see all the infrastructure required to provide the wide coverage area and quality audio of KMOX.
really glad i found this channel. relatively new (4 years in) to IT tech, and this stuff is super interesting to watch, especially the second half of the video. this guy is really an all around master at his craft, he knows the entire site inside and out. pretty cool
Please send a heartfelt thank you to your dad for sharing his many years of experience and know-how with us. So many people must have worked to figure out all these best practices on how to design something we take for granted day to day
My dad works in radio, and i used to walk up to the AM towers. Beautiful sight.
Never touched them, glad I didn't.
Fantastic video, highly informative! down to earth.
Well typically the RF goes out the sides, it wouldn't be as effective going down to earth 😉
I have no idea how this ended up in my feed but this is STUNNING!! It doesn't get more cooler than this!
KMOX, was one of the first stations I
DX'ed back in 1960, when I starting
listening to MW from the NY city area.
It was an RCA portable with mini tubes
and an old type battery.
Some years ago, my wife and I had friends in Dorsey, IL. not too far from
KMOX site. 😊
Thanks for the tour! Brought back some memories of visiting a friend who worked An evening shift at an AM site. Back in the 80’s it was a tube transmitter and you could view the tubes through a lead glass window into the transmitter. Was a 2-way tech until semi retirement in 2006. Largest antenna site I worked on was on top of the John Hancock tower in downtown Chicago. Setting up a high power VHF paging transmitter in the late 80’s.
As a radio/Ham enthusiast I enjoy seeing the big boy setups like this. Pretty cool that ATU is the size of a small building. It was interesting to see that transformer ring for the light power. Very cool stuff. Thanks for including the radials this time. Awesome video.
Fascinating! I went to college in St. Louis in the late 60's and listened to KMOX. Never thought I would get a tour of the RF end of the station, including their "junk box!"
Great job - love this detailed tour! I've always wanted to see inside one of these facilities. Thanks for making this!
Those porcelain insulators are marvels. the little single "petticoats" used for suspending the lowest of the high voltage distribution outside most homes are rated something like 10-30klb tension or compression.
That large one is probably rated 100klb.
There was really short view of a broken one on the ground when they were outside. They're hollow?!?!
@@piquat1I think that was the one that cracked, requiring the rig to hold the tower while they replaced the broken insulator.
@@zoopercoolguy I was a field communications tech. Started out climbing towers but ones less than about 300'. Even those... well there's a LOT of weight there, then the guys and the tension, it's crazy that's all sitting on a hollow ceramic tube. It's crazy enough that they usually kind of come to a point on the bottom to pivot, but that's steel. This is nuts to me and I've been around the "smaller" versions of this stuff.
Kilopound is a cursed ass unit ☠️
Thanks Geerlings! That brings back a lot of memories.
My first job out of college back in the early '80s was with a contracting company that installed transmitters (and studios) including building phasing&matching panels.
It was a great job and taught me a *lot* in the years I worked there.
As someone who was so excited to build a CB base station in a playhouse as a kid learning how to use a SWR meter from radio shack I absolutely love this content. Thank you so much for uploading this.
So much energy that the metal in the doghouse is making a radio speaker. That’s mental.
Your dad’s expression in the thumbnail is fantastic! 😂
Love the content with your dad, I’ve always been curious how broadcast stations work - I’m a ham and had a college radio show for a while.
As a Ham (not a Sad Ham) I'm totally geeking out on these vids. Please feel free to post more. I find them extremely interesting.
Every moment of that tour was fascinating! Well done.
Very interesting tour. I was especially impressed by the solid state transmitter. Thankyou KMOX and crew.
Great video. Brings back memories of my days at KRVN 880 out at Holdrege NE. 50 kW 4 tower directional array. Lots of fun stuff! Thanks for sharing.
I was in the USAF in from `90 - `94 as an AWACS RADAR and IFF Maint technician. The Simpson 260 was the meter in our toolbox.
Thank you for your service Mr. Reid.
Nice to see a well-rounded engineer recording just a small part of his years worth of experience on a little-known subject.
Thank you!
I think you and your Dad are fantastic and it’s great to see your Dad passing the knowledge on it’s so important to us. Great Vids keep it up
I love this sort of stuff. I work in telecom and for a good 10 years we were stationed in the telco central office so it's fun to see different industry's setups.
It's great to have this shared experience with your Dad ❤
This is incredibly awesome, thank you both!
I’m a radio fan but not great at electronics, this was great fun. Much respect for RF engineers.
Well done! Thanks for the in-depth tour. 10/10 and very interesting. Seeing this made me feel a twinge of pride, as KMOX is the AM powerhouse in my region. Soak up all the knowledge you can from your Dad, and men like him, he's a real jewel.
Man, ive been a fan of you for a little over a year or two Jeff, but i have loved radio and radio technology for years. This stuff is teaching me so much (im trying to get my amateur license for the first time) and its very interesting. Thanks for all of the hard work you put into your content. Also, hope youre doing well with your Chrons. I know that can be debilitating as all hell.
This year has been great, knock on wood! No hospitalizations for 2023! (So far... knock on more wood lol)
Hook up with your local Ham Club and they will have an examiner to get you licensed.
I spent 27 yrs as an AM broadcast consultant. Miss those days. My speciality was directional antenna systems. Now retired in Wash DC area.
And yes, RF burns hurt like hell...lol😊😊
I worked at Harris/Gates Air for many years, I never had the pleasure of doing an AM project since the 3DX50 is still the king of the hill. When you're at 90%+ efficiency, there isn't much improvement to make. Really it was just working around component obsolescence issues every so often.
I did have a heavy hand in the TV/FM transmitters under development at the time. I do miss the high power sometimes.
I really enjoyed this video thanks for giving us a tour Geerling crew!
Did a TV transmitter site a few years back from the demo of 3 old analog transmitters and associated matching wave guides and coax to the power to the new dishes out in the field. From the ground up it was allot of work. The grounding of the transmitter was all that and then some! Transmitters and dummy load were all water cooled as well so there was multiple pumps and CAN bus for control and monitor. ERP on the UHF band was about double this site in the video. Fun job being there on the first day of operation and switching over from the previous transmitter site.
I appreciate the in depth explanation of all the buttons, and knobs. Love the long videos too! Thank you for the content gentlemen!
That is so cool that you can hear the station coming off the copper tubes. That is a lot of power!
I love these tours. Currently a technician working on various FAA equipment kind of near St. Louis. It’s always so cool to see the kind of radio equipment that I work on, but on steroids! Please keep the coming!
Is that a hard career to get into?
@@duck_rifle5879 they only post them once or twice a year. A lot of times to their based on FAA needs when it comes to location. They like to have people with backgrounds in electronics, radios, etc which a lot of people get from the military. 2101 ATSS is the job title if you want to look it up
I was waiting for this video for ages. AM Towers are very interesting.Thanks :)
Wow - this was really interesting for us folks who know a bit about radio waves, electronics and transmission etc! Great that you were doing this with your father too!
That’s amazing to walk through there in detail with your dad. My dad was a transmitter broadcast engineer at KMOX-TV in 1969. I remember going when I was young seeing the transmitter.
He was full time at the transmitter for a few years.
This sort of infrastructure, emergency is so fun to watch! Generations have worked on this stuff, so cool to see!
I always love everything radio and broadcast related, it is super interesting to see, keep the videos coming!
It is such an interesting industry, I am really glad to work at a broadcast equipment manufacturer.
I found the walk down History Lane very interesting. I was an engineer for GE Medical Systems for 30 years. The first CT systems we installed required a climate controlled separate room 10x12 just for the racks. Heck a 256meg. not gig.hard drive with 6 discs was about the size of a washing machine. Now days you can run the entire system off a couple of PCs. It's truly amazing the changes that have happened in electronics over the past few decades. And yes I had that Simpson meter
Thanks for the tour of the station, I work around that kind of stuff myself and was laughing at some of the same things I see stored at almost all broadcast facilities. Very well done.
That was a very cool tour of the station...can't believe he has all that knowledge pack in his head man that's a lot to know and remember