1 MILLION watts-really? FM Supertower Part 2!
ฝัง
- เผยแพร่เมื่อ 2 มิ.ย. 2024
- You had a LOT of questions about the 1 million watt FM tower, so we went back, and went even deeper!
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Contents:
00:00 - Megawatt, really? ERP Explained
01:39 - Not all radiation is ionizing
04:05 - Thousands of pounds of rigid coax
05:25 - It didn't fry the drone!
06:39 - Ice and other falling objects
08:12 - A bubble of lightning protection
09:01 - Incandescent? Why not LED?
10:14 - 90-degree coax (not waveguides)
12:00 - Little coax, BIG coax
12:50 - A blue flame of RF
13:35 - Why combine signals?
14:23 - A desk fan is so cool
15:09 - Inside a 30 kW FM Transmitter
15:53 - HD Radio (US) vs DAB+ (EU)
17:31 - Analog tubes? RF burns!
18:18 - Reflected Kilowatts
19:06 - We love hams! - วิทยาศาสตร์และเทคโนโลยี
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10:34 When your coax looks like the water main under the street feeding the fire hydrants, you know you're running some serious power!
Having seen quite a few attempts at explaining large scale antenne technolgy, these videos stand out in every way. The production values are extraordinarily good, the touch of humor and the father-son dynamics add a dimension rarely seen in this type of vid. Extremely well done.
This is the first one I've seen that makes it at least somewhat understandable (RF is still a very complex science beyond my knowledge).
This series is EXTREMELY interesting and your father is a great source of info.
Thank you very much for letting us into your father's work field. Very very nice!
HECK YES IT IS!!!! My mind has been BLOWN many times in just this two videos about the tower!! I CAN'T WAIT FOR MORE!!! :D
Agree
As a former TV chief engineer I have to tell you that your dad did an EXCELLENT job explaining what you were looking at and how it works. (We are usually pretty camera shy!) One "Bad Thing" that you didn't know to ask and he didn't mention was that, depending on power levels, you can get arc-overs (burn outs) between the center of the coax and the outer part (think welding) inside that large copper transmission line somewhere up the tower. That shorts out or dramatically reduces your power to your listeners/viewers and makes for a Very Bad Day. You have to get a tower crew up the tower, find the problem coax segment (20' long each) and swap it out with a new piece of copper coax. Big Bux too! Plus the loss of revenue if you are off the air during the repair.
Thanks for posting this tour video! I brought back) a lot of memories (good and bad)!
Best of luck with the surgery too!
I just went through a line burnout a month ago. The line was pressurized, with a leak at the top. The burnout occurred near the bottom, so all the soot from the burnout was driven up the line. The soot can be conductive and lead to additional burnouts, so it had to be cleaned. The end result was having about 40 vertical hardline sections lowered, cleaned, bullet and o-ring replaced, and returned to service on the tower. It went from an expected quick 3-day repair to a month-long torture... The cost was...significant...
Thx for the enlightenment. Know little of radio xmsn.
This happened in Boston recently .. major TV stations were at 1/10th power for months!
You guys are so good with each other. It's refreshing to see good family function. Also love the deeper dive into that tower, look forward to more.. Good luck on your surgery and speedy recovery..
This is a lot of engineering by the Geerlings!
And many wonderful engineers and tower maintenance employees over the years ;)
Great videos. I am a HAM operator and it's not everyday you get to see all the goodies inside a real transmitter site. Thanks for sharing.
In the late 1960’s, when I was about six, I had the privilege of visiting the transmitter for WHNB, now WVIT, near Hartford. A childhood friend of my father was a broadcast technician there and later became N1AYU. I remember the loud noise from the cooling system and the large klystron that was in a transmitter cabinet. They really are impressive. I would love to see the transmitter room for WCBS 880 here in New York. 50mW AM 😮
I love that you do this with your son. Take all the time you need to heal Jeff, we care about your health!
One point I don't think was mentioned specifically, was that unlike coax, waveguides don't have center conductors, they are just hollow tubes. As the name implies, they just "guide" the wave through the tube and around corners. Though the cross sectional dimensions of all the tubes (are square tubes still called tubes? lol) are all carefully tuned to match the frequency that is passing through and typically are used in the microwave frequency range. I like to refer to it as black magic. lol.
At higher frequencies I was taught the RF travels along the skin of the waveguide. Having been in AM/FM I rarely had work involving waveguides. You’re right about them not having a center conductor. I remember my first time seeing a satellite uplink using waveguide.
In some very high power radar systems, internal RF arcing within the waveguides is suppressed by filling them, under pressure, with sulphur hexifluoride gas.
The distinction is that coax carries what is still an AC electrical signal(at the radio frequency), wave guide carries an electromagnetic wave with e and h fields, like the waves that propogate from the antenna through the air.
Coax can carry a wide range of frequencies,with upper frequency and power limits, waveguide has to be choosen to suit the wavelength of the signal being used.
@@radijoe The "skin effect" works on way much lower frequencies too - like audio. Hence some of the crazy cabinets that are "bi-wired" (not crossed over) as a smaller wire can sound much better on a tweeter. I would have said the same thing as Turbo did above about the waveguides. I am an EE, ham, and have worked at radio stations (but in production). I like your explanation of the inner and outer conductors of a coax but I didn't hear you mention the dialectric. The casual viewer here probably has no idea what impedance is so explaining the ratio between the inner and outer conductor sizzes might be interesting - and maybe why the broadcasters, CB-ers, and hams all use 50 ohms whereas the consumer (rooftop antenna or satellite or cable system) all use 75 ohm coax. I love the way you present things! You know a lot of kids went into engineering in the 60's because of "Scotty" on Star Trek. Hopefullly, you are having that effect on the next gen of RF engineers! :-) "Bucky Dornster" (WKRP) was my hero as a kid. LOL!
@@hotpeppersrcool speaker cabinets and tweeter wires have nothing to do with "skin effect", but are made of unicorn farts by "audiopiles".
Wow, love this! Best luck on your recovery. Hope to see more! As a professional Ansibler, home Pi person and ham radio operator, Jeff and his dad are really making some great stuff!
I was at that site about four years ago. It's very impressive and well kept. That is the 2nd largest FM combiner in the US by number of stations (Empire State Building holds the largest at 19), and the largest by FM combined power. (Miami's Gannett tower is 2nd). That's also the older design of the Dielectric FM-Vee antenna system. It was redesigned after that, and is used in several locations like Tampa. I've actually received a few of those signals here in New England via "E Skip" last summer. And American Tower, who owns the site, is planning on LED retrofits nationwide, so the tower will eventually go LED.
I think xenon strobes still have their place.
we have a couple really big ones in Seattle too but more like 6-8 stations each.
Yeah better replace those 300W incandescent bulbs with 20W LEDs in the 300KW transmitter facility 😆 They do last much longer though IF a) they're cooled properly b) their power supply is cooled properly c) they're not driven too hard. Too often not the case with cheapo household LED bulbs with the power supply built in.
I was at Gannett, did not know it was 2nd largest. It used to host 10 stations but now it hosts 9 if i recall.
I don’t really understand the physics of how combiners work… seems magical and almost impossible to me based on my understanding of RF and my experience with my low power FM station
A thumbs-up is not enough for this video - what a great interview!
I give two 👍
Being an engineer in RF facilities (both TV and Radio), I love the instruction being shown in this video. Being a Ham as well (KC8KVA - I lucked out with that one), you truly respect the RF. Thank you for this follow-up video. It enlightened some of my peers in the workplace. ;)
I've really enjoyed these videos about the Supertower. I guess you know you've arrived at the radio big leagues when you are using copper pipes as coax.
THIS IS WONDERFUL! DAD AND SON... rapid fire questions at the dinner table... poor dad... I love these vids
Hello! Get well soon Jeff!
Thank you! I'm out of the hospital, still have a bit of pain. My Dad and I recorded this a couple weeks pre-surgery, and so I thought it'd be fun to post this while I'm in recovery!
The difference between coax and waveguide is coax carries an electrical current, while waveguide carries rf energy. Waveguide is usually only used when frequencies reach the gigahertz range. At that frequency, the smallest bit of unshielded conductor will act as an antenna and radiate all the energy. I worked in a satellite communications facility back in the 90's and all the transmitters operated at 4-6 Ghz (C-band) and 12-14 Ghz (Ku band). At those frequencies, waveguide was the only option. The transmitters used klystron tubes that created the rf energy directly, so essentially the transmitter was also the antenna.
I loved both of these super tower videos. I can’t wait to see an AM tower and if possible a TV broadcast tower video. The production on here was professional and I really watching the father/son dynamics. It’s informative, interesting, educational and wholesome to watch. Thank you for your time!
Hi Jeff! This is a very interesting format. You and your dad are true masters in delivering complex engineering info to the general public, keep it up! As a SWL (and hopefully ham next year) I can't wait to see the video about MW antennas, as they are truly a wonderful topic, even more than VHF. Sadly, last September in Italy all AM towers were shut down. They provided a very easy way to get news abroad or even in remote areas, where internet connection or FM signal is not a thing. Thank you for your work, greetings from Italy!
Why were the AM stations shut down? AM's pretty scratchy but it can be recieved way out there with ionospheric (?)skips.
Haha. I remember to old HF radio on C-130's way out to Sea. Pilot, Copilot, Engineer all dozing off. But poor Radioman, glued to that scratchy HF the whole ":^^%^&**!@ trip. Squelch cranked up till the poor man could barely hear anything... but static.
@@andreweppink4498 it was due to cut reduction unfortunately. The money that was needed to run the AM stations was certainly "repurposed" for airing questionable shows, as always
Thanks Joe and Jeff for another wonderful look at this tower. Loved the Bird watt meters. Industry standard that still is the gold standard when it comes to that kind of equipment. Lots of nice explanations like in the previous video. Can't wait to see the other videos you talked about doing after you get back from recovering from your surgery Jeff (and I hope you feeling better and healing well). 73 from K0AZV
Thank you so much for covering all the questions, especially considering your health condition!
Hope you are doing well and that from 2023 on your safe and sound!
I’d really like to see so much more RF stuff, please never hesitate to put all possible RF content on your channel 😍
Cheers 🙂
17:00 at least here in austria, most of the broadcast radio service, especially in more rural areas still runs on FM. DAB stations are not so widespread because the old stuff still works great and the infrastructure covers every last corner. In germany they have a lot more DAB stations. 19:10 Also working on my HAM license right now , no wonder i love the Supertower series!
Oh I am not the only guy from austria watching these videos
It only works great because there are people constantly fixing it. Greetings, a rf tech from austria :) (doing tunnel-coverage for example)
@@ExolorLP Yeah of course, things only work if someone keeps them working :) I rather meant sound quality wise FM still does a good job. Tunnel coverage sounds really intresting, i always notice the cell antennas when driving through a tunnel. Do you do this aswell or only radio? Btw so fü österreicher do haha
@@partykeller1553 We do fm radio and emergency service communications. So in case of a fire for example, the firefighters are able to talk with the guys outside and also in the whole tunnel. If you drive trough a tunnel, look at the ceiling and you will notice one or two cables around 10cm from the wall with spacers inbetween them. Thats the antenna that delivers the signal. They are called Strahlerkabel or Schlitzkabel.
@@ExolorLP Is that essentially a leaky coax cable? There's a type of antenna like that but I forget its name, not a typical slot antenna .
Awesome video as always. I've tried (albeit not very hard) to fly drones on our tower sites and have not had much luck. My DJI Phantom wouldn't even get to a point that it was comfortable taking off so I'm very impressed you can fly in front of those roto-tillers without desensing the drone receiver. I think I did get another drone off the ground on a different site but the wind was too much for my skill (mountain top) and didn't even get close to the tower. Speaking of ice, we replace at least one yagi every year due to ice falling. We've even had a hole punched in the roof of our building in the tiny area that was not covered by the ice shield. The ice shield was super bent, it must have been a huge peice.
I have stories of drones and winds! Learning what can and can’t be done while in large open areas is the way I recommend learning. Thanks for the comments.
Being a 'ham', I really appreciate these videos! Thank you.
Haha. Our Little Grandson is a ham. And he has no radio! UHF-FM or anything else.
18:15 RF burns are nasty. Got one from a tiny 15 watt VHF transmitter. Tuning a magloop antenna, got too close to the trimmer's connections. You don't feel it until it starts producing a whisp of smoke, and then it'll take weeks to heal.
Mine was small enough to not be too painful, but even on that scale you can see how deep it burns.
Massive respect for you both - brilliant information and it was nice to see DAB+ given a mention, we've just gone onto a DAB+ platform with our two stations, though sadly I don't do any engineering on that side of things. Can't wait for the next supertower video :) Speedy recovery from your surgery!
best question ever "why aren't we dying right now?"
St Louis native here. Electrical/computer engineer too. This was cool to see!
Fantastic video! A real treat to have a tour of everything with explanation. Keep up the excellent work!
Love the technical details in your videos! Keep 'em coming!
Thanks for shooting another great video! I love the format, please keep it up. And good luck with your operation Jeff, take care!
I absolutely love this content. So much info in an easy to understand format. Please keep doing these kinds of videos!!!
I appreciate these videos on RF, they bring back great memories. I hope you are doing well with your recovery, get plenty of rest and hope to see you back "on the air" soon! Happy Holidays!
This series is interesting because we usually do not get to see it. I love tall antenna towers!
YES! Let's see more of this. I used to change bulbs in Phoenix, AZ on South Mountain the 70's. Short 400' Towers.
Awsome visit and explainations!! Thanks you! I subscribed!
Great video. Thanks for answering all those questions.
Really interesting Thanks a million Jeff. Hope your Surgery goes well and wishing you a pain free and speedy recovery from the UK
I’m pushing only 200,000 real thanks, but using beamforming in the direction of STL at a gain of 7 dB, I have a million effective radiated thanks.
Thanks to you and your Dad for these videos. He is incredibly knowledgable and it's very interesting to see the behind the scenes!
Love your channel dude! Stuff is so interesting.
Hey! That was GREAT. I really enjoyed learning about radio towers and different types of equipment. ...and I had no idea that an AM radio tower carried the signal on the tower itself. I also didn't know anything about an RF burn. Ouch! Thanks for the great information and interesting video. I hope your surgery went well and you're on the road to a speedy recovery.
Great video with lots of good information! An interesting look at what goes on under those tall towers. Thanks!
You guys are so great at this. Really appreciate you answering the questions. Hope you are feeling better Jeff. Dad, you did a great job !
Thanks so much for a really informative video. I'm in the UK, and yes, was still have analogue FM and AM radio stations. No, were not lagging behind the rest of Europe, millions of people still love old fashioned FM and AM! We have a full compliment of DAB and DAB+ stations, available everywhere, it's just that people still love the quality of FM and the nostalgia of AM! Yes, that day will come, but not too soon, I hope.
Not only do you still have AM on Medium Wave over there in the UK but you also still have Radio 4 on Long Wave at 198kHz at least for a few more months. That is REALLY old tech
@@AndyGraceMedia Aaah, but! I doubt many people will still listen to Radio 4 long wave, but as far as I know some services use the signal for time setting, and even switching certain electricity meters onto a cheaper rate after midnight. So once that's all switched over to getting the signals via the internet, they might finally be able to pull the plug on the antique transmitter!
The bit rate and codec used for DAB is not good enough at present for classical music; FM still wins. VHF FM is also needed where there is no DAB service. It is broadcast in a higher frequency band, so is blocked by obstacles and terrain. Likewise, medium- and long-wave AM transmissions are needed for regions where there is no VHF FM signal, usually due to terrain. One more thing, RTÉ in the Irish republic ceased DAB transmissions in March 2021 owing to lack of listeners.
@@cdl0 You're spot on! DAB suffers from the same thing as digital TV, too many channels on some multiplexes. The more channels there are, the poorer the quality is. My biggest gripe with DAB is the low bit rate of classical music stations. FM with a good antenna is by far the best for quality, no comparison.
@@NigelDixon1952 Absolutely right, a Stradivarius on DAB sounds like a cheap east-Asian violin with a bad bow. In addition to low bit rate, the codec is a problem. It was impressive technology at the time when it was developed; however, that was many years ago, and things have moved on. Unfortunately, the codec can't be changed without changing all the hard-coded receivers, so that is unlikely to happen.
Good to know we hams are loved 73s from OH3BPY
Good luck with the surgery and have a swift recovery. Awesome video with soooo much new insights ❤️
I wish you the best on your recovery, Jeff. Videos like this are SUPER interesting. Well done.
Thank you for the tour. Can’t wait for the AM and TV tours!
In Germany we get our radio music through the good, old, reliable fax machine.
Thank you so much for the more detailed follow-up!
So very cool, by far the best series of videos that I've found on this subject. I hope the other ones keep coming.
Thank you for this (again) awesome video. Your father explains the workings in the most clear way I have ever experienced. Even our European DAB system (I live in the Netherlands🇳🇱) is clarified in an easily understandable way. One other difference with FM worth mentioning is the better audio Quality.
I hope you and the people you love are fine. Stay safe!
loved this as well as all the other tower videos you guys have done. Grew up with an uncle as chief engineer of a 50k watt station in the Dayton, OH area and I remember fondly any opportunity I got to visit the station with him. Thank you Jeff and Joe!
I really like the format of this video - the way you posed questions to your father and shared more detail on how a transmitter site worked. Thank you!
Endlessly fascinating, thank you for the detailed tour your dad is awesome.
Great video series! This stuff is super interesting.
I know it's been a few months, but I just watched this video (thanks youtube algorithm) and wanted to add to the LED bulb discussion mentioned in it. I'm a helicopter pilot and during night flights I wear night vision goggles to aid with obstacle and traffic avoidance. Some of these LED marker lights emit a wavelength that is almost invisible to NVGs, negating their purpose for alerting aviators to the tower and required official notices/warnings (NOTAMs) for towers lit with them. This was the case up until just a couple of years ago when it was finally mandated that LED marker lights include an IR component (though some are grandfathered in). It made me happy to see those incandescent bulbs as their inefficiency naturally causes quite a bit of IR. Helicopters spend almost all their time down low and spotting towers is a key survival skill. The guy lines are still deadly though. They're hard to see even during the day. We always fly well away from towers, as long as we can spot them.
Excellent video, very informative.
This is so awesome, thank you very much for these videos.
My prayers and best wishes for a successful surgery and quick recovery.
Very Informative Part 2. Lots of Great Questions. Your Dad is as Knowledgeable as Anyone we’ve been Lucky enough to hear Interviewed. Very Impressive. Thx!
Absolutely love this stuff. Can't wait til the next video shows up. Hope you have a fast recovery from surgery. 👍
Just saw this series. I love RF and mainly in the data transmission space but the explanation from the people that went through the old to the new is fantastic. Thanks to you and your dad, this itched a scratch I have wondered for years on how exactly high output towers worked.
Very interesting and well done! Thank you!
Your video production: Aesthetically outstanding - the Hawk, the Butterfly, the Desk Fan. You and your Dad, a great team. Hope surgery was successful. The content of this and the previous video is impressive. Thanks to all the commenters of the first video and to you, Jeff for making this video to answer the questions.
What an amazing set of videos, thank you for doing this. And glad your surgery went well
Really enjoyed the video & looking forward to the AM one. Best of luck with the surgery!
Absolutely great video and nice tour of the facility. Thank you so much for sharing. I am going to subscribe and will be expecting more! LoL! You asked great questions and your dad did a great job in answering those questions in layman terms. Thanks again and good luck with that surgery. I am so glad to have stumbled upon part 1 and followed up with part 2.... Now off to the low bands!
That was absolutely fascinating! Thank you!
You two are amazing! Hope you make a good recovery after your surgery! Good luck to both of y'all!!
So much that parallels television broadcasting. My first TV station was in college, an ITFS station broadcasting at 2.5 GHz, but my first "real" TV station was a UHF station that used waveguides, and with 800 kW visual and 100 kW aural (both ERP), was close to that magic megawatt classification. But with 10 dB of antenna gain, the real output power numbers for the transmitters were 1/10th that.
I like to explain antenna gain by comparing it to optics. On a sunny day, you can feel the heat of the sunlight, but with a lens you can focus it to set ants on fire. Antenna gain (and beam tilt) focuses the RF energy where there are receivers, so more of it goes where it is needed, and less goes to where nobody is receiving. The benefit is that it saves a lot of power. When your electric bill is $50,000 (yes, I really saw one like that), that 10 dB of antenna gain is saving nearly a half-million dollars a month! Add to that the cost of a megawatt backup generator vs. a 100 kW one, and how long you can stay on the air per tank of gas with each.
Great comments! Thanks!
@@radijoe thanks for the great content!
One of the coolest videos I've seen this year! Yes, I was mesmerized by the scale of things, but also appreciated how the setup was very similar to ham station.
Love this series, can't wait for the AM tower video.
Wow! Great Q&A! Thank you so much! This is so interesting!
Super interesting! Thank you for this video!
Thank you for the cliff notes version.
Amazing explanation of scientific technology/engineering that affects our everyday lives and is mostly taken for granted. Best outcome wishes on your surgery and merry Christmas and bright new year to your family.
Beautiful. Thank you for this effort. First class.
This is such an excellent video. You explain lots of these technical details so very well.
And the video photography is just awesome.
I know a little bit about this topic and if I were teaching a class, this video would be required course material. It provides a wealth of information in an understandable manner.
Loved the aircraft flying above the antenna during the discussion of radiation patterns!
That airplane shot was just pure luck! I noticed a contrail headed towards the top of the tower from my vantage point so I aimed up and started recording!
Fantastic video thanks for sharing. Hope your surgery goes well.
Nice collaboration with your dad. Shared the video with some ham groups here in Portugal. Have a good recovery and good Christmas to all the family.
We Hope your Surgery was Successful and you’re on the Mend. This is a Subject that most people would never think was necessary to listen to a Radio. Thanks! 👍
Very well explained. If you do a Part 3 I would like to see one of these solid state RF transmitters taken apart so that we could see the out put transistors. [in the mid 1970's the UHF 2 way base stations had Transistors on the final output and some did last as long as tubes] Good lighting arrestors are very important. Our base station (on shared site) got hit one night. Our transmitter were tube type with fuses and survived. The mobile telephone system next door were not so lucky as the had some solid state and circuit breakers.
The big difference between the classic tube-based RF transmitters and the modern transistorized ones for AM is that the latter operate in a digital way.
The final amplifiers do not do linear amplification of an exciter signal, but they send out pulses of varying length at a much higher frequency, which when combined and filtered result in the same analog AM signal as a classic transmitter would provide.
However, because the transistors in these modern transmitters are only ON or OFF and not anwhere inbetween ("analog"), they barely get hot and the efficiency of the transmitter is much higher. The entire transmitter can operate at efficiency of around 90% (mains power to RF output) which would be impossible with a linear amplifier, which would be more like 50% efficient.
When you output 50kW, that means you save 45kW of energy when installing such a new transmitter, or 1000 kWh every day.
@@Rob2 thank you for the information. I had not realized how the world of RFI communications has evolved.
Hello you two, this is soooo interesting. Thank you for creating this content and letting us in on your dads work. 👍❤
Thank you for the video, I really like this kind of stuff. All the best for your surgery and a fast recover. See you in the next video.
Wishing you the best with your surgery. Thank you for the follow-up I love the series. It's interesting to hear the explanations and how the big boys do radio. I have been HAM operating for a few years and love all things electronics and radio.
Really nice, want more of this!
Great video - answers a lot of questions
JR
Great Video, work with cell sites and am a ham so it was really neat to see such a powerful site and the people and equipment that support it.
Thanks for sharing
Fascinating. Great video.
Great video! The site is fascinating, Geerling Sr. knows his stuff and is good at explaining it!
Super cool! Thanks for sharing!
very cool video , thanks for making
LOVE your work! You Dad is last of the true engineering generation! Please keep these coming!! Wow!
oh wow part 2 of this!! love it! very very interesting!! cant wait to see the AM tower too!!! thanks for content!
Love this stuff keep it it Geerling guys
Great video, would love to see more!
This was super interesting. More like this please!
Great video. Love your channel.
I used to work at WXYZ AM radio in Detroit. The WXYZ TV tower was on the same property. The guy wires went over the parking lot. We had an ice storm. When the sun came out and warmed the guy wire, the ice would melt and release from the bottom up. There were cars that were impaled with icicles. There were also icicles impaled into asphalt parking lot.
Super cool video! Thank you!❤
Thank you so much for this. Super interesting!!!