Broadcast Transmitter Site Visit

foreign [Music] cast Radio AM extraordinaire we're about to tour a uh Major Market am transmission facility yeah am and uh favorite mode of operation on the ham radio and this is commercial so you guys enjoy the uh the tour storage in addition to being an AM station that's storage for excess and old Misfit antennas so we got 950 Meg STL antennas we got FM antas we got 450 megahertz rpu antennas more FM antennas all kinds of oldie but moldy yeah microwave dishes too this place was built in the uh early 70s originally but call letters were kluc 11 40 a.m okay that's what was on uh Google yes yeah call letters have changed throughout the years but the frequency and the license has not lights on in here um we got AC power in from the utilities and the transfer switch for generator it's the antenna phaser oh okay there are four Towers which and I'll show you guys that uh when we're done here makes a directional array so uh each tower has a tuning Network and it's adjustable for the amount of power that Tower receives and the phase at which the energy is sent to the Tower and by adjusting the amount of power and the time of arrival that signal gets the tower the contrary directional lamp so this is the phaser and do these pretty much stay static all the time yeah very change very little the only time adjustments required is if components in the end tests and change or things in the near field of the attention got it got it Amazon just built warehouses all around right this this property and that did change some of the tuning okay so okay that's why this is adjustable it's just a big giant tuna there's a big tuner um there's Day Day pattern and night pattern during the daytime we're non-directional only one antenna is active and it generates on the directional pattern at night we have a very directional patterns right and is that that auto switch is when the time comes uh whenever it's set up yeah there's a big chunk of Chunk but actually before 6 p.m boom goes over yeah and uh that's uh controlled by our automation system RF current you can see it's moving around this station has what we call mdcl modulation dependent carrier level it reduces the carrier during audio modulation in order to save power oh it makes the transmitter more efficient okay um normally during am the carrier should not change in level uh it's undesirable but uh done right we can see 30 40 Energy savings okay that makes sense that's why the RF current this is the common Point current is changing imagination so here's all of our Command and control equipment we have tuners we have a remote control automation system more remote control automation system we have a 950 Meg STL system we got networking equipment this is the phase monitor this lets us this measures the power and phase at each Tower and we use that information to properly adjust the phase here to produce the pattern desired Transit pattern it's cool down here we have an Orban 9200 audio processor this does it all it's compression it's limiting it's EQ it's bandwidth control um and basically is the the last say in the audio it's what makes am sound of a great it keeps your bandwidth and all that to where legally wants to be and all that for yeah right fcc's happy your loudness levels and all that jazz exactly what we want we never want to exceed uh 99 negative modulation but we absolutely can exceed 100 positive modulation right the our stations we typically run about 135 positive very cool uh and that is the transmission and there's a transmitter Harris so this is a Harris dx10 I'd say 10 kilowatt medium wave am transmitter uh it's solid state it uses uh uh power blocks basically slide in solid state modules with six transistors each and is a digital modulation each module is turned on and off in a in a digital manner to generate the am waveform their pa Supply there we go there you go yep so uh the the amplifier section runs on 240 volts of DC ah okay and I don't know why we don't have any forward current but it's uh typically in the range of uh you know 50 amps uh 50 to 100 right the bigger transmitters can be a couple hundred amps so here's a block diagram oscillator amplifier buffer driver and then the amplifier itself the audio input is convert to digital and a modulation encoder determines which modules in the amp get turned on and off uh that's a very rough waveform and is smoothed out by the band pass fill trapezoid it's an LC ah lots of boards yeah so these are this is the metering here and these are the various control boards modulation coder audio input board that is the oscillator here we have the mdcl board control and then logic in and out this is where we control the transmitter of that terminal block you guys ever have to do any board work or you just replace boards pretty much these transfers are very reliable you probably have to do anything it's uh every once in a while if we have lightning or something like that we'll have to replace uh an amplifier launcher got it and they indicate with a little LED for a fault I'm pretty easy easy peasy maintenance on it yeah even though this is solid state it's not a new design use transparency about early 90s yeah uh quite a long service line nice yeah the uh these transmitters are you know 80 efficient so they're very little heat that's you know there's no windshield I guess change the air filters that's right looks like you guys been hanging out here a bit Yeah somebody this building here this station's been here since the middle of the 70s yeah I've met some of the engineers that just take care of this place but this uh you know there were super transmitters here originally yeah but you know they probably had tube transmitters here at one point that's right yeah they were calling us pollens transmitters and uh 32 V's or something or well probably bigger than that yeah yeah so yeah they would uh spend a lot of time yeah I imagine uh yeah it's uh I'm not proud of the wiring but this is what happens well it's different people throughout the years and uh you know just we got to get one thing running so we'll just add that one thing sometimes right right I'll show you uh big coil yeah conductor variable yeah roller variable this is the control section for the towers all these relays um control solenoids out in the the tower bases the intentoon in its entire bases and uh it switches the bases between day and night so green is day and red is not got it so about uh you know the winter time 4 30 in the afternoon the evenings when we switch to night pattern and about 6 a.m in the morning cool it's very cool and it's loud really it's loud in here yeah bam uh probably scare the crap out of you're not watching the time and you're out here and it changes right yeah yeah I can show you one of we're gonna find one of the relays yeah oh this is one of the antenna changeover relays um this is what changes between it's a double pole double throw it's a silver plated contacts yeah I bet that makes noise boom and this one it's had a hard knock life you see in addition to losing parts that got a little toasty there a little Arkansas yeah lightning is our biggest and I bet those aren't cheap when you gotta replace them very cool Dan very cool some more components here's a uh a roller adapter yeah now that could be a that some hand bows would love that for their tuner and then uh what else we got here oh we got a fixed inductor with taps and then uh get a Caster around here we had a uh Breakers of course that's all right hang up very cool longer and I bet the AC has got to be good in here in the summertime it's 120 out here we actually had had it go out and the dx10 was still running really it was 130 degrees 135 pounds that's a good Transit this stuff's pretty rugged yeah that really shortens the life on the capacitors I bet probably if it was a tube transmitter probably light on fire at that point very cool Dan all right check it out we'll check out some of the town it's gonna be a little bit difficult because we're looking into the sun right whatever's easiest oh look at the yeah the feed line coming down oh yeah oh here's pause see this on the ground this uh this wire yeah a 12 gauge copper and it's been spliced there this is one of the ground radials for the towers each one of these towers has approximately 200 radials extending out from it buried anywhere from a foot to you know a couple inches to a foot foot and a half in the ground right and that uh provides the counterpoints right for the for the tower each one of these towers has yeah you got a vertical you got to have ground radials exactly and how tall are those Towers uh they're about 270 feet just under 300 yeah we want to get somewhere in the vicinity of a quarter wavelength right makes tuning easier um now you don't go up into these towers do you well there's not a whole nothing to do not a whole lot to do except to make sure the tower lights work got it um one of the first Towers I ever climbed was Tower one to change light bulb at the top okay since then uh these have all been converted LED tower lights oh so you don't have to touch them for forever pretty much the copper theft is a big issue with the yeah there's the uh radius Toppers four dollars a pound there's a lot in the ground here thousands of pounds of coffee it's based on one of the towers and uh the the tower is uh series fed meaning uh the the tower itself is insulated the guidelines are insulated and uh the base is insulated from ground all the energy is fed to the base of the Tower um these uh cabinets here are the atus the antenna tuning units they match the base of the tower to 50 ohms okay so the transmission lines are buried coming from the building they're 50 ohms and the ATU is the tuner the phaser isn't an impedance matching device it doesn't tune in that way it adjusts the amount of power going to each one of these towers okay and the phase in other words the time at which the waveform rides up got it so the atus are are really the tuning components are those big ferrites those Rings yeah those Rings The Two Donuts that you see are called Austin ring Transformers okay um they are a Transformer they couple uh 240 volts ac to the tower base okay the lights all right that makes sense so give them a shot back here that was A10 warthog NE so there's three cabinets here because there's more than one AM station this is facility this Tower actually does double duty it's one of the towers in a four Tower array for 11 40. and it's one of three towers uh for 7 20 a.m okay so this small blue cabinet is the ATU for 11. I've listened to 720 up north by me yeah in the big cabinets the ATU for 720. okay this Tower is the the daytime the daytime Tower okay that other cabinet is the filter that keeps the 720 energy out of 1140. okay okay combine those two very cool energy from the ones station right so there's filters on it you can see the copper strap there going to the the units and the base yep all right hey guys we're real close to Nellis so you probably hear a little bit of jet action here that looks like a 16. [Music] [Music] we'll take a walk inside watch your fingers foreign [Music] this this suspended feed line is a is a four inch uh Helix transmission line this gets the FM uh this feeds the FM antennas on this Tower oh okay all the am transmission lines are buried but got it four inch line is for the FM uh combined antenna array so uh we're in daytime power so watch your fingers this four inch transmission line goes in this Barrel looking thing that's a uh an ISO coupler an isolated coupler and what's that do it let's uh and this is FM this is FFM okay so this is a this Tower is doing uh triple Duty actually okay well it is um a tower for 7 20 am it's one of three towers this is a tower for 8 40 a.m and this is also supports an 8 bay FM antenna so to because it's series fed and it's insulated from the ground we couldn't just have an FM feed line going right up the tower it would short it out this ISO coupler uh separates provides isolation from the from for the am energy doesn't get coupled down that transmission line okay while still allowing the FM so we get a close-up here's the Austin ring Transformer you see a piece of seal tight running into it it just passes 240 volts across to the other ring and then into the box which is the tower light controller right and Tyler Tower light controller is a photo cell they only come on at night smart Gap instead of going down the transmission line and tearing up tearing up all the equipment inside here's the FM transmission line hits the tower it's it's uh Shield is bonded and it goes all the way up to the top yep it's a safe to climb rope for climbing I'll take a walk up there yeah take a quick John and uh here's where the energy is actually being passed from the ATU okay to the base cover yeah so it's probably uh it's probably 20 amps of RF energy flowing through there I'm saying I shouldn't grab that right now probably a couple hundred volts would be a bad idea if you grabbed it have a bad time yeah I'd be calling uh taking a ride to the cemetery after that if I if I had a fluorescent tube I could wave it there and it would light up yeah yeah okay thank you so if you listen closely minus the jet minus the jet I heard it tickling I hear the audio Yeah you can hear the station there's a loose joint that is these are interlocked so I I'm not going to open them that's fine that's fine yeah we don't need to go off the air and have a problem yeah she wants some ham guy that stuff and took the whole damn station off the air very cool so here's that since we're out of this song You Can Count the towers up that's Tower one for 11 40. and this is Tower two and that's three three further ones four okay five Towers in total but those four are the the 11 40. these two middle 11 40 towers and the tower behind us Tower five are the three towers which comprise the 720 AM okay assistant and this Tower by itself uh is our backup antenna for 8 40 a.m which the main transmitter is at a different site about 10 miles okay got the egg insulators I bet you those aren't some cement for sure yeah yeah this goes about about 15 feet and there's a couple tons of concrete down there cool guy lines are are broken up every uh 80 feet or so so that they are electrically invisible yeah this Tower five was set up to handle a lot more power the insulators are larger these are the same kind that you would see on transmission lines you know on power lines uh and this guy right here is a a choke it allows DC to pass so that there's no static buildup it's a lightning protection got it I think but these are silicon huh fiberglass silicone do those have to be replaced at certain times are you just pretty much handle the handle the weather for for a long time many years it was an engineer's good idea uh a lot of them are already broken because lightning hit them ah okay and uh I don't think they're effective and they're supposed to shunt any charge to ground before light before it can build up and have a lightning strike right lighting is going to hit lightning Sky yeah you just gotta you just gotta move the power away okay it's close yeah there's good view of the top of the tower um you can see the top 100 feet approximately is freestanding and it supports the 8 bay FM antenna you can zoom in on that that antenna serves as a backup for 94.1 FM 98.5 100.5 and 107.5 so if the those stations the transmitters are located on Black Mountain in Las Vegas if those are off the air for any reason uh this facility acts as backup here we go here's our uh our main building this house is all the equipment that is being transmitter definitely a lot louder in here a lot louder we have a lot more equipment yeah a lot more equipment but we have five projected air conditioners got this building was built with all the air conditioning and the power and the room to actually support other stations so that so that it leads out they can lead right and that's actually it's the combiner and stuff to find more 10 kilowatt FM transmitters into that single four inch transmission line these are three pole filters each station backup transmitter for 8 40 am it's 10 kilowatts and it beats a one Tower non-directional the transmitter and then more van audio processor let me know when that goes on sale I'll put that on 160. foreign oh okay the train is better it's uh here is 3gx 50 and more modern version yeah and this is a Heron's dx10 this is the backup transmitter for 720. okay so lean and backup transmitter are both here we can switch between them and well with uh this control panel here got it this is the phaser for 720 there's three towers and you can adjust the power and the face that's fed to each Tower at night time it's directional and in the daytime there's one Tower active and it's not a direction we also have a dummy load that we can switch to either transmitter yeah that's a big dummy load yep nice toasty too yeah I thought it does good job of Plumbing this up you can see all the copper transmission line this is the backup transmitter for 11 40 AM it's in this new building because the intention was to move all the 1140 equipment out of the whole building into this building the phaser and the main transmitter okay is that another dummy load there yeah so this is a 10 kilowatt FM transmitter this is this transmitters for 107.5 FM and these newer Gates air transmitters are for uh uh 94 1 98.5 and 100.5 so this is just the transmitter right here that's it wow you've got a lot smaller yeah yeah yep all modules it's here cooled uh these are the power amp modules and these are the power supplies these are actually server grade so they're commercially available right um uh these amplifier modules run on 50 volts those are okay 48 volt server supplies economies this is the Exciter in here and the audio processor some backup computers and some audio streaming equipment we have a unlicensed 5.8 data lake or controller okay so we have a 950 megabytese development on the football side 12 year old here's some uh some am stuff [Music] oscilloscope and uh that combined with the Spectrum analyzers one of the cabinets you run 25 kilowatts in a day and seven and a half a couple months apologies they're cool without a whole lot to see in here but this is a power supply cabinet okay we remove those panels right high voltage everywhere yesterday let's look inside there there's a four power rate modules and uh eight power supply modules fuel redundant exciters and then command and control [Music] as as the signal as it is right now let's take a peek all our FM stations are HD so you'll see the uh the FM carrier there in the middle and then the two pedestals on the side is the HD that's the HD okay because you're sending digital stuff that's like our that RDS or whatever you just receive on your fm or you get that info is that what that is or no no RDS is actually embedded in the in the audio okay uh HD radio is uh completely separate from that mountain over there okay okay um it's uh actually you could you could have HD and no FM or you could have you know uh all HD right it's called eibach in band on channel meaning that those digital pedestals are in the same channel but they're insane band but they're not actually the oppositions we got it um separate modulation okay okay we'll just transmitter does both of them got it all right mate okay lots of spares yeah those are actually burned up house yeah a bad one of them yeah and I'm assuming like you guys are back in office Studio this all this stuff's alarmed you know and something goes bad you get the alarm you gotta hop in the truck and come up here and check it out Yeah we actually have two different remote control systems uh this one is a burke so they're they're a manufactured it's like home automation but for nerds right for broadcasting and uh separate unit we have both the Avatar same things it's home automation for technical facilities um for each piece of equipment we wire in a status closure sometimes metering and they provide a 0 to 10 volt zero to five volt measurement and then we can require relays out of control okay so this is all the metering status and command uh wires for this facility so each one of those wires doesn't function such as you know transmitter on transmitter off or the transmitter is on or the transfer is off or the transmission alarm or it's a variable signal such as uh this voltage is uh the measured change in the power outages lots of hookups okay prepare for those FM transmitters all these run on 240 volts so they all have their own Breakers and such three phase uh these are actually single phase okay but the am transfers are already three yeah yeah back up there's a cap yeah 0.001 microfarad yep another a variable inductor am tuning unit yep spares on the Shelf there's a uh this is a static drain choke this drains any uh any energy from the tower to ground uh it's slightly promotion okay heart prevention well that's always a big concern when you got all those big towers like that that's just a Target so here's a here's a transmission line for for RF you can see it's got a an outer jacket and Center conductor okay and Teflon insulators so this is a really low loss really uh high power handling much different than what ham guys are used to that's for sure we don't use braided coaxial cable right we just don't hold the power they just don't hold the power and they're they're not rugged glossy yeah and we're not flexing either right we don't have to worry about uh use of installation that's all custom fitted very cool there's a this is a a three and an eighth inch transmission elbow that got burnt up I see that yeah so that's what happens when you run you know 30 40 kilowatts and you have you know two to one SWR you start burning stuff up yeah those are Teflon insulators silver plated copper Center conductor and solid copper jacket flanges those are here we have isolation Transformers step down this building is 480. so these Transformers convert uh to 240 243 base all right well that's going to be your transmitter killer I think Dan for the big walk around and uh hope you guys like it [Music] [Music]

Channel: Wavelength Radio

Views: 14,012

Keywords: icom, drake, swan, net, ham radio, vintage radio, am, ami, am international, radio nets, diy, antique radio, repair, restoration, sdr, anan, flex radio, sdr play, n9ami, broadcast, commerical, fm, radio, tour, transmitter, site, las vegas, nevada

Id: J0EYTrfki4g

Length: 40min 33sec (2433 seconds)

Published: Wed Dec 21 2022