@@IfYouLikeGoodIdeas We bought a couple of Harris Tx of that generation. It seems like, at that time, there was a "rookie" in the overseas export section, as they were sent complete, unlike the normal process of packing the heavy stuff separately. Miracles do happen, & one arrived intact---with the other one, sadly, the modulation transformer had come loose, rampaging through the fragile bits, so we had to spend months fixing it. There were always "niggling" little faults with that particular unit, so it looks like its bad luck stuck with it
From someone who has never worked on a high power transmitter. What is the function of the little rectangular box above the 2 3phase circuit breakers? I have seen a similar box on the early 30s /GE/RCA transmitters as well.
That's the overcurrent sensor for the low-voltage plate circuit. The relay inside it latches on in the event of an overload, which then shuts the transmitter down.
In the early '70s during college, I worked a 16 hour weekend shift as the transmitter engineer for a 50kw day/ 10kw night AM station. Our day pattern fed 2 towers and went to 9 towers at night. The daytime transmitter was an RCA Ampliphase BTA-50G. As I recall, the power supply used 6- 857B MV rectifiers that were almost 2 feet tall. It ran at about 16KV at 4 amps. The blowers on that thing were really loud. Unlike a typical plate modulated transmitter, this was essentially 2 phase modulated transmitters with a network on the output side that vector summed the phase shift of the 2 transmitters so as to create an amplitude modulated signal to the antenna. We needed to be sure not to exceed 100% modulation, or the result would be horribly distorted audio. The transmitter tubes were huge and required a lifting device to change them. Luckily I never had too. The doors on the power supply cabinet had spring loaded shorting bars that would discharge the capacitors if the door opened. Get ready to change your underwear if you weren't expecting a loud snap. The night transmitter was a plate modulated RCA 10D from the 1930s that was retired from use by the state police when they used to operate near the AM broadcast band. This thing was like a giant ham transmitter in that tune up and operation were the same. There was a huge modulation transformer that sat in a cage behind the transmitter. It also had 2 large brass balls to form a spark gap for over modulation. This transmitter had no forced air cooling and it was a dream to take that 50kw unit off line at night. You could hear the modulation transformer and it sounded like a tweeter. The inductors it the antenna tuning huts also acted like tweeters. I had a lot of fun working at this station and really enjoyed your video of the well preserved 5G.
Could that have been WJAC 850 AM Johnstown, PA ? I know they have an 9 tower array and would switch to a northern broadcast pattern at night. I remember 10W but not sure of 50W (most 50W were clear channels?) Stretching my memory! Thanks
@@FirstLast-ye5ct It was WCAR 1130 kHz (Class B) in Detroit with the transmitter site in Trenton, MI south of Detroit. It was not a clear channel station, hence the need to lower power and change the pattern at night. The day pattern used 50 kW feeding 2 towers with a strong lobe to the north and lesser to the south. The night pattern had to protect stations in other states while covering the metro Detroit to mid Michigan region. The station went through numerous format changes over the years. When I started, they were shifting from 50s- 60s pop music (Sinatra, Peggy Lee, Doris Day, Nat King Cole etc) to a top 40 rock format. Sometime after I left, they became WCXI with a Country Music format, then WWW (don't recall the format), then WDFN Sports Talk and now the Black Information Network. The WCAR call sign still exists in the Detroit market with a low power station on 1090 kHz (250 watts day, 500 watts night). WJR 760 kHz is a 50 kW Class A clear channel station also near Detroit with a single tower and omni directional pattern. Here are some links that might be of interest- radio-locator.com/info/WDFN-AM (Click on the gps coordinates and choose satellite view to see the tower arrangement), mcrfb.com/?cat=32 , www.weather.gov/jetstream/ll_ampm_stations.
Especially given the fact that this transmitter is in perfect operating condition, I certainly hope that you can take steps to prevent this from ever being dismantled and thrown away. I recently had been forced to dispose of a GATES BC-5B that could have easily been put back into service. Great job on keeping this alive and thanks for such a wonderful video.!
Had similar experience with a recently replaced ‘50s RCA 3kW FM transmitter. If was free for the hauling away, but what could I possibly do with it? The chief engineer saved the modulator and logo.
@@davidcarson4421 Install it in the trunk of your very large car, as an aux-to-FM adapter...? :-D Seriously though, this is cool as. But, I would imagine modern designs are WAY more power-efficient, with less out-of-band hash, considerably more reliable, and easier to troubleshoot. There's probably no good reason to keep one of these in service. Though I do hope a few are saved for posterity, regardless. How a glass bulb in one place can create music in a clock-radio dozens of miles away, will always seem magical to me.
As a retired TV repair technician, I appreciate the care and craftsmanship put into older equipment. RCA was really RCA and not a name used by a Chinese company.
Those tubes you were talking about looking at -- they do put off some UVB and UVC, but even that thin glass plate in front of it would completely absorb all of it. Even the glass of the tube itself probably absorbs the vast majority of the UVC. So I wouldn't worry too much about it. You could always grab a UV sensor from Adafruit and take some readings. Anyway, this thing is absolutely awesome. I would love to hear this thing actually on the air!
As a little kid, I used to dream of working on radio transmitters, and that every visit to the local radio station and seeing the transmitters operate in full power was a thrill.
Radio stuff isn't one of my interests, but this is still a really cool piece of kit even if I don't understand 90% of it. Thank you for taking the time to give us this tour and demonstration!
As a young man, I used to help the station engineer at the remote transmitter site out in the sticks when lightning repairs etc. required some overnight work. He was a polio victim with leg braces and often needed some extra help. The 1KW transmitter used two 4-400 RF output tubes. I was a ham and he would let me have some of the older 4-400 tubes for my 1KW ham rig. Those were the days. I once volunteered to climb the tower half way and replace a burned out light. I will never do that again. My legs were like jello afterwards. Fond memories.
I enjoyed your tour of this transmitter. You voice and laughter conveys enthusiasm and positive tone. I worked for an AM station in Topeka Kansas. KEWI back in the early 70s which used a Collins 21E. We used mercury vapor rectifiers in the hi and Lo voltage power supplies. Modulation would really get those guys a blinking. They later went to solid state rectifiers.
@Frank Roberts Hi Frank, Yes I remember both stations well. They also inspired me to go for the 1st class radio telephone ticket. I worked at two tv stations in addition to KEWI until 1972 and went into avionics as engineering tech. Many of the broadcasting engineers we had back then came from Forbes AFbase or former Forbes stationed.
Marvelous transmitter. KUGN (Eugene) ran the very similar BTA-10, operating at 5kW, thru 1978 when it was replaced by a Continental. Amazingly solid, good sounding, and reliable. Also easily capable of 110% to 120% positive given the oversized components.
Wow, this takes me back. I worked at a station in the late 70's, that was using a 1 KW Raytheon, (1947 vintage), at night, directional 4 tower array. Daytime, we used an RCA BTA-5, non-D. The RCA BTA-5 was only 2 units though. There wouldn't have been enough room at the transmitter site for that mega-monster 5KW that you showed here. I was one of the jocks at the station, but was at the x-mitter site on many occasions. It was nice to take a trip back to the fun old times of radio. I got paid crap, but I had fun.
When I was 14 years old living in a Suburb of Detroit in 1957. I made my own radio station. I hooked up my Heath kit RF generator to my 45 record player I and build a hybrid transmitter circuit with 6l6 and is a couple 12ax7s I think and some other parts I found and was putting out about 5 watts in my neighborhood at about 660 am so us kids could listen to our records. The FCC showed up at my parents house and threaten my parents with jail if I didn't shut it down. Us kids knew a lot in 1957
About 20 years ago I got the unofficial B tour of a long time popular AM radio station's backup transmitter while working on a cell site nearby and chatting up the engineer for the station through the fence during a smoke break. Similar equipment and vintage. They kept it operational rather than installing more modern equipment since it was there, still worked, parts were still available and it was easy to maintain. A few months later a small plane crashed into their new tower at their new location and they had to fire up the old one and operate from it for months. Their newer site had more power but their old site had high elevation. During their back up operation I was working on another cell site a good 900 miles away and I was able to pick them up on my truck radio at night no problem. I live about 400 miles from there now and I can tell when their new site is under maintenance because I can pick them up here day or night while they are on their backup.
Thank you. They don't build anything like they used to anymore. As for the beast at WQXR in NYC long gone is that trusty Westinghouse 50HG-2 Transmitter, and same as you have found out, A Harris 10K stand by back up was so unreliable very temperamental. By the way, Modulation Transformer and Reactor were almost as tall as me. And I stand 6' and every now and then you would get a SNAP sound as the arc gap on top of that reactor went off. 😂 This was a great video of day's gone by. Today's transmitter sites both AM, FM, and TV have no soul or humans standing watch 24/7 gone is an era I will remember. 👍👍
I worked in a radio station many years ago that had a Gates BC-1 transmitter. Our running joke was, we didn't know if that was the model number or the year it was built. It had two 807's and four 833's. The unit was about the size of a large refrigerator. We could always tell when trouble was brewing in that monster when one or more 833 would start glowing a VERY bright orange.
That would be the era before a move to 4-400 glass tetrodes, with a round base socket. Either design used 2 tubes for a class C RF final, and 2 tubes for a class B audio amp feeding the modulation transformer. In that power range Gates used dry transformers, and so there weren'tPCB HazMat issues found in larger transmitters, or in some capacitors when not of dry film construction.
very cool to see another old rca transmitter operating. in my state we also have a functional old rca transmitter, a bta-50f from 1945 installed on vashon island in washington and operated by komo am 1000. it's so big it has man doors on it and you walk around inside of it to service it.. it's a massive beast.
That RCA transmitter is a true American Machine. Beautifully made, simple, reliable, serviceable, and it might last as long as you can get tubes for it. Plus, being crystal controlled, zero phase noise! A super clean transmitter signal is the result.
I worked on the preceding RCA model (BTA 5F) installed in circa 1947 at 620 kc in Knoxville and a following model, the RCA (BTA 5R) installed in 1959 at 1310 kc in Asheville and both were built very well and very reliable. (Between the 5G and 5R models, there was the 5H, which was a 5G with a beefed up plate transformer, and the 5J and 5L, which were the 5 KW versions of RCA's Ampliphase design,.) I installed a new Collins transmitter in Knoxville and literally gave the 5F away. At the time (about 1980) I did not see the beauty of the 5F, but looking back it was a huge mistake not to keep it as a backup (we had a newer transmitter to backup the new Collins rig). Also, it was almost whisper quiet due to the large cooling fins on the 892R final tubes not needing a high pressure blast of cooling air. The 5F worked perfectly, but even in 1980 it was very inefficient, but it could have been left in service as another backup and would probably still be viable today unless it lost a transformer, especially the modulation transformer which was known to fail on the 5F. Plate voltage on the 5F was 18,000 volts due to the low current capability of the 892R tubes which stressed the mod transformer. I imagine the tubes for the 5F became difficult if not impossible to get; we were using rebuilt tubes from Freeland (which was later bought by Econco) in the 1980's and I do not see 892R on Econco's list of tubes they have available. The 5F still had the MV rectifiers up to 1980, but the 5R had the 8008's replaced with silicon rectifiers sometime in the 1960's Both the 5F and 5R used a conventional three phase rectifier for the HV, which IMHO are much more reliable, but did not give the ability to control the power as finely as the thyratrons did. The thyratrons seem unnecessarily complicated to me. I guess RCA also decided that when they came out with the 5R. Like the 5G in this video, the 5R used a pair of 5762s in the RF amplifier, but used 3X3000F1s for the modulator, which I think probably was probably a better choice of tube for that purpose. The drivers were completely different, a pair of 4-125As each for the RF and modulator. Don't know what became of the 5R at 1310 as I sold that station in 1986. BTW, in 1969-1970 I lived in Western New York and had an occasion to visit WSAY back then. If my memory is correct, the 5G was what was on the air and it sounded like it needed the modulator tubes to be replaced. For the way the station looked back then, and the way it sounded (appearing to not be very well maintained) this 5G is in really good, and clean, condition! I hope the owners of the station keep it in service.
I am amazed to see one still working! I used to work on a RCA BT10K 27 years ago when I started in radio business.... Same design almost. And we had a Harris MW1 iKw as backup. Thanks for the video!
Thank you for showing us this awesome grandaddy of a transmitter it was absolutely fascinating to see you start it up! I used to listen to AM radio a lot as a child here in the UK (we had a few pirates) and have always been fascinated by AM transmitters and how they operate. The running hours is staggering when you do the math. 507125 hours is 21130 days or a staggering 57.89 years 😳 Hearing the audio resonance from all the components within has a real charm to it and it deserves to run forever.
I'm surprised the Hg vapor tubes weren't replaced with generic plugin solid state rectifier units. The time for mercury to vaporize was 5-15 minutes, whereas the glass or finned metal power triodes and tetrodes was only in the one to five minute range. The PSM (progressive series modulation) in the Harris MW series eliminated the modulation transformers and their artifacts, though the newer series digital AM transmitters using banks of power MOSFETs are even more efficient and use more reliable components. Digital transmitters skip the entire idea of A3 modulation, and merely generate a digital analog of a modulated waveform, and switch power at a clock multiplier of carrier frequency, and then filter artifacts. A 5 kW nominal transmitter would likely have a 50 kW peak capacity, to cover 5400 watts carrier power into a directional array phasor, plus some reserve capacity, and to handle 125% or more peak positive modulation envelope instantaneous power needs. Overall (line to load) AC efficiency is around 30-35% on those old tube beasts, around 50% for an MW series Harris, and around 65% on newer digital transmitters (the Nautel among those), which pays for the entire newer transmitter with a bonus of better audio quality over its lifetime. FWIW, I'm a semi-retired broadcast engineering consultant.
I started in radio in 1967 (on FM) and by the time I 'worked up' to AM, these were no longer around. I often wondered what they looked like and you showed in great detail what I have long wondered. I bet I would have gotten along well with that old girl. I was in the room with one 30 years ago and still remember hearing it 'singing' the Children's Marching Song by Mitch Miller. It was an honor to be in the same room. Thanks very much for taking the time to walk me through the innards of this majestic transmitter.
Your story bleeds awesomeness. What an honour to witness such great engineering. I’ve been on the telecom side for most of my working life, I’ve seen some wild things more in the realm of microwave vs fm/am but certainly hope to see some before my time is up!
Its like im listening to my dad again... he was an electronic engineer for Helicrafters, AKA Northrup. You explain things, almost touching scary energized stuff so casually, its a bit disconcerting. (like my dad:) That Jesus stick... one day dads coworker started working on a high power transmitter just like that. Dad and other engineer walked up ready to do his thing, confirmed with him it was all discharged... Reached in to start working, and woke up in the hospital, his right hand and arm burned / permanently damaged. He always blamed himself for not checking. Even though the other guy was working in there for hours already, and should have discharged High V caps he actually was removing??? He lost most feeling, then later because of that burned his hand BAD on a soldering iron changing tips. literally didnt know it was on and held it till he noticed his hand was smoking...EEEK.
That was really cool. One of these things most people will never get to see in person or work on. Something so cool about tubes and analog electronics though, how you can actually see and hear it work.
About 1979 I got hired as a transmitter engineer at WARM "The Mighty 590" in Avoca PA. Actually I didn't know anything, I was a college freshman and newbie Ham radio op. In fact I think maybe a Ham Op got me the job? The transmitter was basically 5 towers out in a farm field miles from the studio. I never saw the studio. Fun job while it lasted which wasn't long. The owners replaced most of us transmitter baby-sitters with automation. I wish I had taken some pictures of the facility but I didn't have a camera (and of course that was before the era of smartphones with cameras- or even 'dumb phones") Thanks for the transmitter tour.
Now it's just another feeble bleep of its former self. Like so many other stations of its time. A CB base station with a linear amp puts out more power. Now the latest trend with these dinosaurs is to go to low power FM.
It is a shame that so many old, beautiful transmitters have been thrown away. Of course it worked! I never thought it wouldn't. RCA All the WAY. Wasn't the prettiest transmitter but worked well. Just by you firing that up the stations electric bill went up for the entire year. Gotta watch firing up backup transmitters when you are on a demand meter. It can run up the bill for the next year just by running it a few minutes
I wanted to be a radio engineer. At 13 I had my 3rd class FCC license. Then I was installing radios in cars. Cars became my passion. Retired an ASE master technician. Wish I stuck with radio, my back would be in better shape. Thanks for the tour.
Well, your back might be in better shape, but your bank account wouldn't. Maybe as an engineer. Radio owners don't like to pay their employees, at least not the on-air.
@@SerenityMae11 As an entrepreneur radio installer and being good at it you can make big money. Especially once the late 80s and early 90's hit, car stereos were hot shit and anyone that cold wire them up to make the big boom was making enough to wear a gold suit and top hat. The same happened in 2003+ when everyone wanted TV's and more entertainment capable stereos.
Dunno, in my years in Radio/TV Broadcasting, I've lugged some massive stuff round, grovelled under building floors, climbed ladders, & even dragged my complaining old bones up TV towers. At the same time, I worked on cars at home for fun----go figure!! :-)
Hmmm Negative peaks higher than positive peaks means you got the audio phase going into that thing backwards also many of those old mercury vapor rectifiers were replaced with Xenon gas filled more modern replacements that were not nearly as prone to Arc back. Finding parts for the Harris MW5 PDM transmitter would be a challenge and I imagine a chore to maintain, glad you guys made the decision to keep the old RCA as a back-up.
My dad was a chief engineer at a AM station in early 50's and I remember as a kid going out to the transmitter with him to check on things. Mainly remember the tremendous heat coming out of the equipment. Thanks for the video!
A little about selenium rectifiers. I once owned one that was rated 250 V at some tens of milliamperes. Needless to say, I eventually wanted to see, " what it had had for breakfast". Actually nothin very exciting -- definitely less than an alarm clock internals... However, the alarm clock internals never smelled like the eventually blown selenium rectifier! Later on, I was in a job, where I got many more smell incidents. There we used stacks of much larger selenium plates as over voltage clamps, something similar as present MOVs (metal oxide varistors). We bought the plates in quantity and assembled the stacks ourselves. Each plate was good for about 30V. But as said, occasionally some strong spike exceeded the voltage and avalanche current at some plate, shorting it and then the voltage on the remaining plates increased and the failures propagated through the entire stack. The smell provided an easy trouble shooting. You knew what had happened instantly at entering the room, or often even outside.
The Nautel is stress free. The RCA not so much. My husband's dad was a station GM. What they went through with tubes, rebuilt tubes and lightning. Also their 1964 era RCA could not modulate much beyond 84%. The Nautel would be a different story in so many ways beginning with the cabinet size. I have deepest respect for both transmitters, RCA equals our history and the Nautel the future. What I truly love is GATES Boards and if I owned a station I'd use remanufactured ones in the control & production rooms.
A few years ago, I was working on a line at the KDKA AM transmitter site. The original 50kW transmitter looked like this RCA and was still on site (I believe the site guy said it was being maintained as a back-up) and they were operating a new solid state 50kW Harris Transmitter for their main.
I live about 20 minutes from the KDKA site and would absolutely love to see that old beast in person - I've seen pictures. It'd be so awesome if they put it back on the air at some point even for just a bit. I've always dreamed of picking up a 50,000 watt giant from a tube transmitter on my transistor radio. I'm 21 now, so solid state has been the thing for stations during my lifetime.
A trained ear could easily tell the difference. Most AM broadcast transmitters sound like crap, because some engineer that knows nothing, cranks all knobs to the right to make it LOUD. Some of the best AM audio can be heard on stations like KFBK and KGO in northern California. As well as WSM in Nashville. J.
@@jimw7ry I'd leave KFBK AM out of that list. What sounded bad in general was AM stereo, which was touted as having only slightly perceptible distortion.
@@jimw7ry Not just am, most fm stations are unlistenable- total compressed crap. The stations in houston, save one or two non-commercial stations are unbearable to listen to on a nice Marantz stereo system or similar.
Having never worked AM, the closest I ever came to tube transmission was working at a Class A FM with a Collins 830-E backup running at 3.3 kW. Not nearly as sexy as one of these old RCAs (or even a Continental, for that matter), although the site was operationally unique in that it was the first hydro-powered commercial FM in the US! When we were running on hydro you could watch the power meters fluctuate slowly with the flow of the water through the turbine...
I visited this site in 1965 when it was WSAY1370. the studio was upstairs in the house on French Rd. in Brighton NY. the owner, Gordon P Brown, had built the station in 1936 when it was one of 3 existing am's licenced to Rochester (the others being WHAM 1180 and WHEC 1460.) I believe it started at 1210 pre-NARBA. it originally was well-staffed but following an announcer strike, Brown operated it on the cheap as a combo operation... as of 1966, they ran Bell home tape recorders rather than cart machines.
Right you are, Leon. I first visited in 1960 when it was a split operation and the equipment was fairly new. I started working there in 1966..same equipment, and replaceable Bell transports. (There were several downstairs in the engineering shop on standby). The station employed full-time first class phone operators to handle the original directional 1kw operation and then the 5k nighttime operation. After upgrading to 5k, daytime was NDA. There were 4 stations in a two mile radius, WHEC (1460), WSAY (1370) WVET (1280) and WBBF (950). The first 3 were 5k DA-N and BBF was 1kw DA-2. The WSAY studios were to move to 250 East Avenue after Gordon Brown got the license for Channel 13. He started building in the early 60s but lost his bid for TV and then just gave up. The studios remained on the 2nd floor of 560 French Road until his passing in 1979.
Dave I spent 2 years at the U of R. Tried to get a weekend job at SAY but was told no because I didnt have a car. I beard BBF could never get the full 5kw because it was too close to 950 in Utica,
It's at 560 French Road, Rochester NY. Watt, it was 1 1/2 miles from the house I lived in when we moved to the suburbs. The "studio" and control room were upstairs in the building. The ground system was very poor and produced a huge RF buzz on the sidebands. I worked there from Feb 66 to September 67.
Great video. The MW-5A was sort of a dog; I maintained a couple of them. The RF module transistors would blow constantly. Eventually, replacement transistors were difficult or impossible to come by. I bought some of the last stock that Harris had for WMAS in Springfield, MA back around 2004.
Yeah, if you were outside the rear of the Tx building at 6WF/WN Tx site, you could clearly hear the 6WF program from the modulation transformer of the 55kW STC Tx. We had 6WF on 720kHz at 55kW, 6WN on 810kHz at 10kW, (these shared the same antenna), & the "regional shortwaves" VLW & VLX, which served the Northern parts of Western Australia. VLW was 10kW & VLX 50kW. All the Tx were STC, except the standby for 6WN, which was Philips. Strangely enough, the 10kW standby for 6WF was a totally different STC model to the 6WN main Tx. Watching the video really "took me back"----I could almost smell the old tube Tx smell!
Printed circuits wouldn't work for this monster anyway. Reliability is the key, and there's lots of voltage, heat, and current. By the way, I build tube audio by hand, point to point, so I see this sort of construction all the time.
My stepfather Thomas Franken, was the audio engineer for Ebbets Field,City Field And also a transmitter repairman maintainer. He knew a lot of stuff and he traveled with the Dodgers Just in case they needed him. He had breakfast while he was traveling to St Louis with Jackie Robinson!! So he had a good life! A baseball life!
I have a J1000 Nautel that replaced a Harris MW1 that replaced I think a BC1 that I had wish I had kept and took home. Fun stuff. All my FM is still tube. The MW1 is mostly working after a lightning strike but I wasn't able to get the rest of the parts. The J1000 has something in it that you can hear the audio especially when the gospel singing ladies get loud.
The thyratron tubes are fired by a rotary pulse transformer which can be adjusted to alter the phase relationship between the high voltage AC and firing pulses
You´re such a nerd, I love the chirp-i-chirp, that thing is very cool. I very much enjoyed the tour, I hope You keep Your job, they are lucky to have You nerd at this place. In Germany am is dead. As a kid in the 70´s it was awsome, sooo much going on on am and shortwave. Even some number stations. Now it´s clear what they were but then they were just strange to me. I love radio. Have a nice day!
It was good to see some vintage broadcasting gear that still works. I happen to be a retired Broadcast Chief Engineer and your transmitter brought back many memories! I want to point out that I saw you touching some of the tubes with your bare hands, I recommend that you do not do that. I say that due to the oils and other contanaments on your hands can create hot spots on the tube in the area that was touched and cause premature failure. Many of the stations that I took care of had kept their old tube transmitters after going solid-state and kept one tube transmitter as a backup. I am not sure if they have them now, I expect not. I retired in the first week of 2013 and then moved south to Florida. While in retirement I am doing some contract work with several stations here and I do love doing the work, down here 90% of my work is rebuilding Antenna Phasers and Transmitter Finals that suffered Lightning Damage. I will keep doing my contract work for as long as I can, I feel blessed that I have a profession that I love doing and to me it is my play ground and have kept up with all of the technology changes through the decade's.
Yes, the RCA 5kW is indeed a much cooler tx! I had the privilege of working on one that was converted to a 10 kW. RCA had a conversion 'kit' to make it 10 kW. Nice vid!
Don't ever, and I mean EVER lose your passion for broadcast engineering, because when you reach "old fartdom", it's the memories, Slavic foods, and bitching about how music has sucked since 1987 which gets you through the days..... The 'oil filled' items, there's a second way to monitor their sealed status, which greatly augments the visual protocols: Purchase a decent grade Combustible Gas Leak Detector (refrigerant type); when caps and xfrmr's were impregnated and saturated/filled, most had
Several years ago, I took a tour of the transmitter site of CFRB, Toronto. It's a similar vintage transmitter that runs 50 KW. There's a bit of history in it's call sign. CFRB was founded by the Rogers Vacuum Tube company to promote the company's batteryless receivers. Ted Rogers invented the indirectly heated cathode, which mean a battery for the heaters was no longer needed. Hence the letters R(ogers) B(atteryless) became part of it's call sign. This Ted Rogers was the father of Ted Rogers Jr., who founded Rogers Cable and was owner of several TV & radio stations, a cell phone network and more.
Wow, learn something new every day. I knew about the rogers battery-less tube he invented but not the CFRB RB relation. Cool! Thank you. EDIT: I realized most CRT's used such indirect heated cathodes too. That was such a widely used very important invention of that era.
@@spikester While I knew about that years ago, it's also mentioned in the Wikipedia article about CFRB. You can add to this CFRB is now owned by Bell Media and Bell is Rogers' main competitor for TV, cell phone network and Internet.
Reminds me of the outer limits episode about the alien the radio station owner captured by a dj accidentally captured in a radio beam by turning it up after he was told not to.. TURN IT UP.
OOOOOH MY GOOOOOD... THIS DUUDE IS A GENIUS AND HE TALK LIKE THE N E R D LEWIS SKOLNICK FROM THE MOOWIE NERDS.. I AM A HAM/AMIGA NERD MY SELF .. SO GO ""LEWIS """ YOU ROCK BRO.. EVEN LAUGH SAME WAY
love the video - nice flashback of Classic RF Technology. But yes, as a few others have mentioned, you could work on the every second sentence is a end with laughter. the repeated giggles and laughter is a bit obnoxious since you are trying to do a documentary and only a handful of things you described were actually funny.
A most excellent tour, of a most excellent piece of 1950's technology. I know little about transmitters, but am assuming it's audio is plate modulation? I know ham transmitters from the 50's were sometimes screen modulated, and that's why I'm asking. I had a friend who used a Johnson Viking 500 starting using during the early 70s through the early 90s. He wound on occasion operate the 500 with it's cover off in order to enjoy the bright fuchsia Color That was given off by what I believe to be 2x 811's. Thanks for the walkthrough.
keep the old transmitter going mate. as for the unhappy Harris, you are more than welcome to send it to me
Vacuum tubes rock! Thanks for sharing.
Now there's an AM beast... heh..heh.... Splendid!
I wish I had a big farm to hoard all this gear
Be rebuilding and making my own glass tubes
Omit the giggles and the video would be good
@13:47 Up here on the top....we have some sweet shag carpet
Was that Harris one of the ones that had many boards, each with like 100 W output that were all paralleled?
No, that Harris is still old enough to use a tube for its final amp.
@@IfYouLikeGoodIdeas We bought a couple of Harris Tx of that generation. It seems like, at that time, there was a "rookie" in the overseas export section, as they were sent complete, unlike the normal process of packing the heavy stuff separately.
Miracles do happen, & one arrived intact---with the other one, sadly, the modulation transformer had come loose, rampaging through the fragile bits, so we had to spend months fixing it. There were always "niggling" little faults with that particular unit, so it looks like its bad luck stuck with it
From someone who has never worked on a high power transmitter. What is the function of the little rectangular box above the 2 3phase circuit breakers? I have seen a similar box on the early 30s /GE/RCA transmitters as well.
That's the overcurrent sensor for the low-voltage plate circuit. The relay inside it latches on in the event of an overload, which then shuts the transmitter down.
@@IfYouLikeGoodIdeas Thank you.
In the early '70s during college, I worked a 16 hour weekend shift as the transmitter engineer for a 50kw day/ 10kw night AM station. Our day pattern fed 2 towers and went to 9 towers at night. The daytime transmitter was an RCA Ampliphase BTA-50G. As I recall, the power supply used 6- 857B MV rectifiers that were almost 2 feet tall. It ran at about 16KV at 4 amps. The blowers on that thing were really loud. Unlike a typical plate modulated transmitter, this was essentially 2 phase modulated transmitters with a network on the output side that vector summed the phase shift of the 2 transmitters so as to create an amplitude modulated signal to the antenna. We needed to be sure not to exceed 100% modulation, or the result would be horribly distorted audio. The transmitter tubes were huge and required a lifting device to change them. Luckily I never had too. The doors on the power supply cabinet had spring loaded shorting bars that would discharge the capacitors if the door opened. Get ready to change your underwear if you weren't expecting a loud snap. The night transmitter was a plate modulated RCA 10D from the 1930s that was retired from use by the state police when they used to operate near the AM broadcast band. This thing was like a giant ham transmitter in that tune up and operation were the same. There was a huge modulation transformer that sat in a cage behind the transmitter. It also had 2 large brass balls to form a spark gap for over modulation. This transmitter had no forced air cooling and it was a dream to take that 50kw unit off line at night. You could hear the modulation transformer and it sounded like a tweeter. The inductors it the antenna tuning huts also acted like tweeters. I had a lot of fun working at this station and really enjoyed your video of the well preserved 5G.
Could that have been WJAC 850 AM Johnstown, PA ? I know they have an 9 tower array and would switch to a northern broadcast pattern at night. I remember 10W but not sure of 50W (most 50W were clear channels?) Stretching my memory! Thanks
Cool .. ! Well said Wb0siy
@@FirstLast-ye5ct It was WCAR 1130 kHz (Class B) in Detroit with the transmitter site in Trenton, MI south of Detroit. It was not a clear channel station, hence the need to lower power and change the pattern at night. The day pattern used 50 kW feeding 2 towers with a strong lobe to the north and lesser to the south. The night pattern had to protect stations in other states while covering the metro Detroit to mid Michigan region. The station went through numerous format changes over the years. When I started, they were shifting from 50s- 60s pop music (Sinatra, Peggy Lee, Doris Day, Nat King Cole etc) to a top 40 rock format. Sometime after I left, they became WCXI with a Country Music format, then WWW (don't recall the format), then WDFN Sports Talk and now the Black Information Network. The WCAR call sign still exists in the Detroit market with a low power station on 1090 kHz (250 watts day, 500 watts night). WJR 760 kHz is a 50 kW Class A clear channel station also near Detroit with a single tower and omni directional pattern. Here are some links that might be of interest- radio-locator.com/info/WDFN-AM (Click on the gps coordinates and choose satellite view to see the tower arrangement), mcrfb.com/?cat=32 , www.weather.gov/jetstream/ll_ampm_stations.
Loved it 😊
@@ctbcubed Do you still work in Radio?
Especially given the fact that this transmitter is in perfect operating condition, I certainly hope that you can take steps to prevent this from ever being dismantled and thrown away. I recently had been forced to dispose of a GATES BC-5B that could have easily been put back into service. Great job on keeping this alive and thanks for such a wonderful video.!
Dam what a waist
Had similar experience with a recently replaced ‘50s RCA 3kW FM transmitter. If was free for the hauling away, but what could I possibly do with it? The chief engineer saved the modulator and logo.
@@davidcarson4421 use it as a very powerful spark speaker in a Faraday cage
Or
To drive a tesla coil
Quite a few other things
@@davidcarson4421 Install it in the trunk of your very large car, as an aux-to-FM adapter...? :-D
Seriously though, this is cool as. But, I would imagine modern designs are WAY more power-efficient, with less out-of-band hash, considerably more reliable, and easier to troubleshoot. There's probably no good reason to keep one of these in service. Though I do hope a few are saved for posterity, regardless. How a glass bulb in one place can create music in a clock-radio dozens of miles away, will always seem magical to me.
@David Carson I would have find something to do with it. Believe me 😆
As a retired TV repair technician, I appreciate the care and craftsmanship put into older equipment. RCA was really RCA and not a name used by a Chinese company.
You’re a good guy to show that beautiful old rig. Love the shag carpet trim.
That looks more like sprayed asbestos fire proofing to me.
Those tubes you were talking about looking at -- they do put off some UVB and UVC, but even that thin glass plate in front of it would completely absorb all of it. Even the glass of the tube itself probably absorbs the vast majority of the UVC. So I wouldn't worry too much about it. You could always grab a UV sensor from Adafruit and take some readings.
Anyway, this thing is absolutely awesome. I would love to hear this thing actually on the air!
As a little kid, I used to dream of working on radio transmitters, and that every visit to the local radio station and seeing the transmitters operate in full power was a thrill.
Radio stuff isn't one of my interests, but this is still a really cool piece of kit even if I don't understand 90% of it. Thank you for taking the time to give us this tour and demonstration!
Love it!!! Run it on the air and play some Wolfman Jack!
Good old AM miss them days makes me think about having fun with just a AM Philco Ford Transistor pocket radio
As a young man, I used to help the station engineer at the remote transmitter site out in the sticks when lightning repairs etc. required some overnight work. He was a polio victim with leg braces and often needed some extra help. The 1KW transmitter used two 4-400 RF output tubes. I was a ham and he would let me have some of the older 4-400 tubes for my 1KW ham rig. Those were the days. I once volunteered to climb the tower half way and replace a burned out light. I will never do that again. My legs were like jello afterwards. Fond memories.
I enjoyed your tour of this transmitter. You voice and laughter conveys enthusiasm and positive tone. I worked for an AM station in Topeka Kansas. KEWI back in the early 70s which used a Collins 21E. We used mercury vapor rectifiers in the hi and Lo voltage power supplies. Modulation would really get those guys a blinking. They later went to solid state rectifiers.
@Frank Roberts Hi Frank, Yes I remember both stations well. They also inspired me to go for the 1st class radio telephone ticket. I worked at two tv stations in addition to KEWI until 1972 and went into avionics as engineering tech. Many of the broadcasting engineers we had back then came from Forbes AFbase or former Forbes stationed.
Marvelous transmitter. KUGN (Eugene) ran the very similar BTA-10, operating at 5kW, thru 1978 when it was replaced by a Continental. Amazingly solid, good sounding, and reliable. Also easily capable of 110% to 120% positive given the oversized components.
Wow, this takes me back. I worked at a station in the late 70's, that was using a 1 KW Raytheon, (1947 vintage), at night, directional 4 tower array. Daytime, we used an RCA BTA-5, non-D. The RCA BTA-5 was only 2 units though. There wouldn't have been enough room at the transmitter site for that mega-monster 5KW that you showed here. I was one of the jocks at the station, but was at the x-mitter site on many occasions. It was nice to take a trip back to the fun old times of radio. I got paid crap, but I had fun.
When I was 14 years old living in a Suburb of Detroit in 1957. I made my own radio station. I hooked up my Heath kit RF generator to my 45 record player I and build a hybrid transmitter circuit with 6l6 and is a couple 12ax7s I think and some other parts I found and was putting out about 5 watts in my neighborhood at about 660 am so us kids could listen to our records. The FCC showed up at my parents house and threaten my parents with jail if I didn't shut it down. Us kids knew a lot in 1957
Thanks for that. Very interesting. I really enjoy watching quality old equipment like this still working. Unlike the throw away society today!
About 20 years ago I got the unofficial B tour of a long time popular AM radio station's backup transmitter while working on a cell site nearby and chatting up the engineer for the station through the fence during a smoke break. Similar equipment and vintage. They kept it operational rather than installing more modern equipment since it was there, still worked, parts were still available and it was easy to maintain. A few months later a small plane crashed into their new tower at their new location and they had to fire up the old one and operate from it for months. Their newer site had more power but their old site had high elevation. During their back up operation I was working on another cell site a good 900 miles away and I was able to pick them up on my truck radio at night no problem. I live about 400 miles from there now and I can tell when their new site is under maintenance because I can pick them up here day or night while they are on their backup.
Thank you. They don't build anything like they used to anymore. As for the beast at WQXR in NYC long gone is that trusty Westinghouse 50HG-2 Transmitter, and same as you have found out, A Harris 10K stand by back up was so unreliable very temperamental. By the way, Modulation Transformer and Reactor were almost as tall as me. And I stand 6' and every now and then you would get a SNAP sound as the arc gap on top of that reactor went off. 😂 This was a great video of day's gone by. Today's transmitter sites both AM, FM, and TV have no soul or humans standing watch 24/7 gone is an era I will remember. 👍👍
I worked in a radio station many years ago that had a Gates BC-1 transmitter. Our running joke was, we didn't know if that was the model number or the year it was built. It had two 807's and four 833's. The unit was about the size of a large refrigerator. We could always tell when trouble was brewing in that monster when one or more 833 would start glowing a VERY bright orange.
That would be the era before a move to 4-400 glass tetrodes, with a round base socket. Either design used 2 tubes for a class C RF final, and 2 tubes for a class B audio amp feeding the modulation transformer. In that power range Gates used dry transformers, and so there weren'tPCB HazMat issues found in larger transmitters, or in some capacitors when not of dry film construction.
I love the blue glowing tubes!! Also, great use of Photonicinductions sayin!
very cool to see another old rca transmitter operating. in my state we also have a functional old rca transmitter, a bta-50f from 1945 installed on vashon island in washington and operated by komo am 1000. it's so big it has man doors on it and you walk around inside of it to service it.. it's a massive beast.
That RCA transmitter is a true American Machine. Beautifully made, simple, reliable, serviceable, and it might last as long as you can get tubes for it. Plus, being crystal controlled, zero phase noise! A super clean transmitter signal is the result.
I worked on the preceding RCA model (BTA 5F) installed in circa 1947 at 620 kc in Knoxville and a following model, the RCA (BTA 5R) installed in 1959 at 1310 kc in Asheville and both were built very well and very reliable.
(Between the 5G and 5R models, there was the 5H, which was a 5G with a beefed up plate transformer, and the 5J and 5L, which were the 5 KW versions of RCA's Ampliphase design,.)
I installed a new Collins transmitter in Knoxville and literally gave the 5F away. At the time (about 1980) I did not see the beauty of the 5F, but looking back it was a huge mistake not to keep it as a backup (we had a newer transmitter to backup the new Collins rig).
Also, it was almost whisper quiet due to the large cooling fins on the 892R final tubes not needing a high pressure blast of cooling air.
The 5F worked perfectly, but even in 1980 it was very inefficient, but it could have been left in service as another backup and would probably still be viable today unless it lost a transformer, especially the modulation transformer which was known to fail on the 5F. Plate voltage on the 5F was 18,000 volts due to the low current capability of the 892R tubes which stressed the mod transformer.
I imagine the tubes for the 5F became difficult if not impossible to get; we were using rebuilt tubes from Freeland (which was later bought by Econco) in the 1980's and I do not see 892R on Econco's list of tubes they have available.
The 5F still had the MV rectifiers up to 1980, but the 5R had the 8008's replaced with silicon rectifiers sometime in the 1960's
Both the 5F and 5R used a conventional three phase rectifier for the HV, which IMHO are much more reliable, but did not give the ability to control the power as finely as the thyratrons did. The thyratrons seem unnecessarily complicated to me. I guess RCA also decided that when they came out with the 5R.
Like the 5G in this video, the 5R used a pair of 5762s in the RF amplifier, but used 3X3000F1s for the modulator, which I think probably was probably a better choice of tube for that purpose. The drivers were completely different, a pair of 4-125As each for the RF and modulator.
Don't know what became of the 5R at 1310 as I sold that station in 1986.
BTW, in 1969-1970 I lived in Western New York and had an occasion to visit WSAY back then. If my memory is correct, the 5G was what was on the air and it sounded like it needed the modulator tubes to be replaced. For the way the station looked back then, and the way it sounded (appearing to not be very well maintained) this 5G is in really good, and clean, condition! I hope the owners of the station keep it in service.
I am amazed to see one still working! I used to work on a RCA BT10K 27 years ago when I started in radio business.... Same design almost. And we had a Harris MW1 iKw as backup. Thanks for the video!
Thank you for showing us this awesome grandaddy of a transmitter it was absolutely fascinating to see you start it up! I used to listen to AM radio a lot as a child here in the UK (we had a few pirates) and have always been fascinated by AM transmitters and how they operate. The running hours is staggering when you do the math. 507125 hours is 21130 days or a staggering 57.89 years 😳 Hearing the audio resonance from all the components within has a real charm to it and it deserves to run forever.
Absolute nerd, but he knows his stuff.
I'm surprised the Hg vapor tubes weren't replaced with generic plugin solid state rectifier units. The time for mercury to vaporize was 5-15 minutes, whereas the glass or finned metal power triodes and tetrodes was only in the one to five minute range.
The PSM (progressive series modulation) in the Harris MW series eliminated the modulation transformers and their artifacts, though the newer series digital AM transmitters using banks of power MOSFETs are even more efficient and use more reliable components. Digital transmitters skip the entire idea of A3 modulation, and merely generate a digital analog of a modulated waveform, and switch power at a clock multiplier of carrier frequency, and then filter artifacts. A 5 kW nominal transmitter would likely have a 50 kW peak capacity, to cover 5400 watts carrier power into a directional array phasor, plus some reserve capacity, and to handle 125% or more peak positive modulation envelope instantaneous power needs.
Overall (line to load) AC efficiency is around 30-35% on those old tube beasts, around 50% for an MW series Harris, and around 65% on newer digital transmitters (the Nautel among those), which pays for the entire newer transmitter with a bonus of better audio quality over its lifetime.
FWIW, I'm a semi-retired broadcast engineering consultant.
I started in radio in 1967 (on FM) and by the time I 'worked up' to AM, these were no longer around. I often wondered what they looked like and you showed in great detail what I have long wondered. I bet I would have gotten along well with that old girl. I was in the room with one 30 years ago and still remember hearing it 'singing' the Children's Marching Song by Mitch Miller. It was an honor to be in the same room. Thanks very much for taking the time to walk me through the innards of this majestic transmitter.
Your story bleeds awesomeness. What an honour to witness such great engineering. I’ve been on the telecom side for most of my working life, I’ve seen some wild things more in the realm of microwave vs fm/am but certainly hope to see some before my time is up!
Yeah, my Grandfather, now deceased, sold these RCA transmitters. No wonder he was so successful. They don't build them like that anymore!!!
Its like im listening to my dad again... he was an electronic engineer for Helicrafters, AKA Northrup.
You explain things, almost touching scary energized stuff so casually, its a bit disconcerting. (like my dad:)
That Jesus stick... one day dads coworker started working on a high power transmitter just like that.
Dad and other engineer walked up ready to do his thing, confirmed with him it was all discharged...
Reached in to start working, and woke up in the hospital, his right hand and arm burned / permanently damaged.
He always blamed himself for not checking. Even though the other guy was working in there for hours already, and should have discharged High V caps he actually was removing??? He lost most feeling, then later because of that burned his hand BAD on a soldering iron changing tips. literally didnt know it was on and held it till he noticed his hand was smoking...EEEK.
That was really cool. One of these things most people will never get to see in person or work on. Something so cool about tubes and analog electronics though, how you can actually see and hear it work.
I liked this video alot, very well made it honestly felt like i was getting a tour from someone who really knows and enjoys the place
About 1979 I got hired as a transmitter engineer at WARM "The Mighty 590" in Avoca PA. Actually I didn't know anything, I was a college freshman and newbie Ham radio op. In fact I think maybe a Ham Op got me the job? The transmitter was basically 5 towers out in a farm field miles from the studio. I never saw the studio. Fun job while it lasted which wasn't long. The owners replaced most of us transmitter baby-sitters with automation. I wish I had taken some pictures of the facility but I didn't have a camera (and of course that was before the era of smartphones with cameras- or even 'dumb phones")
Thanks for the transmitter tour.
Now it's just another feeble bleep of its former self. Like so many other stations of its time. A CB base station with a linear amp puts out more power. Now the latest trend with these dinosaurs is to go to low power FM.
It is a shame that so many old, beautiful transmitters have been thrown away. Of course it worked! I never thought it wouldn't. RCA All the WAY. Wasn't the prettiest transmitter but worked well. Just by you firing that up the stations electric bill went up for the entire year. Gotta watch firing up backup transmitters when you are on a demand meter. It can run up the bill for the next year just by running it a few minutes
From the looks of the room those are in…WXXI 1370? Been there many moons ago if so
This is waaaaay cool. Into electronics, but unfamiliar with transmitter rigs. Did a great job - thanks!
I wanted to be a radio engineer. At 13 I had my 3rd class FCC license. Then I was installing radios in cars. Cars became my passion. Retired an ASE master technician. Wish I stuck with radio, my back would be in better shape. Thanks for the tour.
Well, your back might be in better shape, but your bank account wouldn't. Maybe as an engineer. Radio owners don't like to pay their employees, at least not the on-air.
The automotive industry doesn't pay well either.
@@SerenityMae11 As an entrepreneur radio installer and being good at it you can make big money. Especially once the late 80s and early 90's hit, car stereos were hot shit and anyone that cold wire them up to make the big boom was making enough to wear a gold suit and top hat. The same happened in 2003+ when everyone wanted TV's and more entertainment capable stereos.
Dunno, in my years in Radio/TV Broadcasting, I've lugged some massive stuff round, grovelled under building floors, climbed ladders, & even dragged my complaining old bones up TV towers.
At the same time, I worked on cars at home for fun----go figure!! :-)
That thing will still live after an EMP attack.
The newer ones however will not.
I wish there were some oldies stations around here. The only am stations where I live are gospel, news, sports and spanish music
wonder why. That is new trend somehow.
@@singhpk99 because am has bad quality
Back in the day when AM made money they sounded top notch.
@@cascade5682 never sounded as good as fm. Never. FM is clear and stereo. Am is mono and will always be kinda fuzzy
That Laugh is stupid
Hmmm Negative peaks higher than positive peaks means you got the audio phase going into that thing backwards also many of those old mercury vapor rectifiers were replaced with Xenon gas filled more modern replacements that were not nearly as prone to Arc back. Finding parts for the Harris MW5 PDM transmitter would be a challenge and I imagine a chore to maintain, glad you guys made the decision to keep the old RCA as a back-up.
sound the tardis dr who dr 1.and 2 from. the. 60s
Is the blue BIC pen cap OEM?
My dad was a chief engineer at a AM station in early 50's and I remember as a kid going out to the transmitter with him to check on things. Mainly remember the tremendous heat coming out of the equipment. Thanks for the video!
Wow, what a great tour, thank you. Back when radio had some soul.
What is so funny???
When you got the mind of a rocket scientist but making minimum wage at the radio ranch.
@@pedrodepacas4335 I think I totally understand what you are saying.
It's amazing how something like this is still considered a technological marvel.
Kudos to the owners for not dismantling the RCA
4:32 what's the pen cap squeezed between the red box and the casing for?
A little about selenium rectifiers. I once owned one that was rated 250 V at some tens of milliamperes. Needless to say, I eventually wanted to see, " what it had had for breakfast". Actually nothin very exciting -- definitely less than an alarm clock internals... However, the alarm clock internals never smelled like the eventually blown selenium rectifier!
Later on, I was in a job, where I got many more smell incidents. There we used stacks of much larger selenium plates as over voltage clamps, something similar as present MOVs (metal oxide varistors). We bought the plates in quantity and assembled the stacks ourselves. Each plate was good for about 30V. But as said, occasionally some strong spike exceeded the voltage and avalanche current at some plate, shorting it and then the voltage on the remaining plates increased and the failures propagated through the entire stack. The smell provided an easy trouble shooting. You knew what had happened instantly at entering the room, or often even outside.
The Nautel is stress free. The RCA not so much. My husband's dad was a station GM. What they went through with tubes, rebuilt tubes and lightning. Also their 1964 era RCA could not modulate much beyond 84%. The Nautel would be a different story in so many ways beginning with the cabinet size. I have deepest respect for both transmitters, RCA equals our history and the Nautel the future. What I truly love is GATES Boards and if I owned a station I'd use remanufactured ones in the control & production rooms.
A few years ago, I was working on a line at the KDKA AM transmitter site. The original 50kW transmitter looked like this RCA and was still on site (I believe the site guy said it was being maintained as a back-up) and they were operating a new solid state 50kW Harris Transmitter for their main.
I live about 20 minutes from the KDKA site and would absolutely love to see that old beast in person - I've seen pictures. It'd be so awesome if they put it back on the air at some point even for just a bit. I've always dreamed of picking up a 50,000 watt giant from a tube transmitter on my transistor radio. I'm 21 now, so solid state has been the thing for stations during my lifetime.
I'd like to hear what that old transmitter sounds like compared to a modern transmitter. I wonder if a listener could tell the difference
A trained ear could easily tell the difference. Most AM broadcast transmitters sound like crap, because some engineer that knows nothing, cranks all knobs to the right to make it LOUD. Some of the best AM audio can be heard on stations like KFBK and KGO in northern California. As well as WSM in Nashville. J.
@@jimw7ry I'd leave KFBK AM out of that list. What sounded bad in general was AM stereo, which was touted as having only slightly perceptible distortion.
@@jimw7ry Not just am, most fm stations are unlistenable- total compressed crap. The stations in houston, save one or two non-commercial stations are unbearable to listen to on a nice Marantz stereo system or similar.
Having never worked AM, the closest I ever came to tube transmission was working at a Class A FM with a Collins 830-E backup running at 3.3 kW. Not nearly as sexy as one of these old RCAs (or even a Continental, for that matter), although the site was operationally unique in that it was the first hydro-powered commercial FM in the US! When we were running on hydro you could watch the power meters fluctuate slowly with the flow of the water through the turbine...
I worked at a station that had one of these.. An awesome transmitter!
I visited this site in 1965 when it was WSAY1370. the studio was upstairs in the house on French Rd. in Brighton NY. the owner, Gordon P Brown, had built the station in 1936 when it was one of 3 existing am's licenced to Rochester (the others being WHAM 1180 and WHEC 1460.) I believe it started at 1210
pre-NARBA. it originally was well-staffed but following an announcer strike, Brown operated it on the cheap as a combo operation... as of 1966, they ran Bell home tape recorders rather than cart machines.
Right you are, Leon. I first visited in 1960 when it was a split operation and the equipment was fairly new. I started working there in 1966..same equipment, and replaceable Bell transports. (There were several downstairs in the engineering shop on standby). The station employed full-time first class phone operators to handle the original directional 1kw operation and then the 5k nighttime operation. After upgrading to 5k, daytime was NDA. There were 4 stations in a two mile radius, WHEC (1460), WSAY (1370) WVET (1280) and WBBF (950). The first 3 were 5k DA-N and BBF was 1kw DA-2. The WSAY studios were to move to 250 East Avenue after Gordon Brown got the license for Channel 13. He started building in the early 60s but lost his bid for TV and then just gave up. The studios remained on the 2nd floor of 560 French Road until his passing in 1979.
Dave I spent 2 years at the U of R. Tried to get a weekend job at SAY but was told no because I didnt have a car. I beard BBF could never get the full 5kw because it was too close to 950 in Utica,
What graceful machines these were. Glad to see this one remains.
Thanks for the tour.
Where is this by the way?
wh
WXXI(AM), Rochester, NY
It's at 560 French Road, Rochester NY. Watt, it was 1 1/2 miles from the house I lived in when we moved to the suburbs. The "studio" and control room were upstairs in the building. The ground system was very poor and produced a huge RF buzz on the sidebands. I worked there from Feb 66 to September 67.
Amazing piece of equipment, they don’t build to last like this one anymore. Thanks for the tour. 👍👍
You guys should operate it for Christmas or special seasonal programs, just for that 'ol sound!
LS 82 TV Canal 7 50 m
I wonder if I could heat my house with that thing...
Yes you can
With the filaments and blower into the room.
Great video. The MW-5A was sort of a dog; I maintained a couple of them. The RF module transistors would blow constantly. Eventually, replacement transistors were difficult or impossible to come by. I bought some of the last stock that Harris had for WMAS in Springfield, MA back around 2004.
It's fun to imagine you training a new employee while laughing at every part as you explain how the system works.
Optimods are fine for old TXs... Modulation transformers just like to sing. Great vid. :)
Yeah, if you were outside the rear of the Tx building at 6WF/WN Tx site, you could clearly hear the 6WF program from the modulation transformer of the 55kW STC Tx.
We had 6WF on 720kHz at 55kW, 6WN on 810kHz at 10kW, (these shared the same antenna), & the "regional shortwaves" VLW & VLX, which served the Northern parts of Western Australia.
VLW was 10kW & VLX 50kW.
All the Tx were STC, except the standby for 6WN, which was Philips.
Strangely enough, the 10kW standby for 6WF was a totally different STC model to the 6WN main Tx.
Watching the video really "took me back"----I could almost smell the old tube Tx smell!
Printed circuits wouldn't work for this monster anyway. Reliability is the key, and there's lots of voltage, heat, and current. By the way, I build tube audio by hand, point to point, so I see this sort of construction all the time.
My stepfather Thomas Franken, was the audio engineer for Ebbets Field,City Field And also a transmitter repairman maintainer. He knew a lot of stuff and he traveled with the Dodgers Just in case they needed him. He had breakfast while he was traveling to St Louis with Jackie Robinson!! So he had a good life! A baseball life!
I have a J1000 Nautel that replaced a Harris MW1 that replaced I think a BC1 that I had wish I had kept and took home. Fun stuff. All my FM is still tube. The MW1 is mostly working after a lightning strike but I wasn't able to get the rest of the parts. The J1000 has something in it that you can hear the audio especially when the gospel singing ladies get loud.
The thyratron tubes are fired by a rotary pulse transformer which can be adjusted to alter the phase relationship between the high voltage AC and firing pulses
You´re such a nerd, I love the chirp-i-chirp, that thing is very cool. I very much enjoyed the tour, I hope You keep Your job, they are lucky to have You nerd at this place. In Germany am is dead. As a kid in the 70´s it was awsome, sooo much going on on am and shortwave.
Even some number stations. Now it´s clear what they were but then they were just strange to me. I love radio. Have a nice day!
It was good to see some vintage broadcasting gear that still works. I happen to be a retired Broadcast Chief Engineer and your transmitter brought back many memories! I want to point out that I saw you touching some of the tubes with your bare hands, I recommend that you do not do that. I say that due to the oils and other contanaments on your hands can create hot spots on the tube in the area that was touched and cause premature failure. Many of the stations that I took care of had kept their old tube transmitters after going solid-state and kept one tube transmitter as a backup. I am not sure if they have them now, I expect not. I retired in the first week of 2013 and then moved south to Florida. While in retirement I am doing some contract work with several stations here and I do love doing the work, down here 90% of my work is rebuilding Antenna Phasers and Transmitter Finals that suffered Lightning Damage. I will keep doing my contract work for as long as I can, I feel blessed that I have a profession that I love doing and to me it is my play ground and have kept up with all of the technology changes through the decade's.
What a beautifull piece of art! Real, functioning steampunk
Yes, the RCA 5kW is indeed a much cooler tx! I had the privilege of working on one that was converted to a 10 kW. RCA had a conversion 'kit' to make it 10 kW. Nice vid!
Wouw, At the begining, I can see a Tektronix T932 or T935, my first oscilloscope was a T932
Excellent video except the constant giggle/laughing which there was nothing funny to laugh about.
Don't ever, and I mean EVER lose your passion for broadcast engineering, because when you reach "old fartdom", it's the memories, Slavic foods, and bitching about how music has sucked since 1987 which gets you through the days..... The 'oil filled' items, there's a second way to monitor their sealed status, which greatly augments the visual protocols: Purchase a decent grade Combustible Gas Leak Detector (refrigerant type); when caps and xfrmr's were impregnated and saturated/filled, most had
Several years ago, I took a tour of the transmitter site of CFRB, Toronto. It's a similar vintage transmitter that runs 50 KW. There's a bit of history in it's call sign. CFRB was founded by the Rogers Vacuum Tube company to promote the company's batteryless receivers. Ted Rogers invented the indirectly heated cathode, which mean a battery for the heaters was no longer needed. Hence the letters R(ogers) B(atteryless) became part of it's call sign. This Ted Rogers was the father of Ted Rogers Jr., who founded Rogers Cable and was owner of several TV & radio stations, a cell phone network and more.
Wow, learn something new every day. I knew about the rogers battery-less tube he invented but not the CFRB RB relation. Cool! Thank you. EDIT: I realized most CRT's used such indirect heated cathodes too. That was such a widely used very important invention of that era.
@@spikester While I knew about that years ago, it's also mentioned in the Wikipedia article about CFRB. You can add to this CFRB is now owned by Bell Media and Bell is Rogers' main competitor for TV, cell phone network and Internet.
@James Knott aware of the Bell smell part, that was obvious from its failure of content today.
Wildly cool to see something like this thats still in use, or at least kept in working condition as part of a commercial venture. I love it.
I wont ask how you get replacement parts for this Jurassic era item. :o
Reminds me of the outer limits episode about the alien the radio station owner captured by a dj accidentally captured in a radio beam by turning it up after he was told not to.. TURN IT UP.
OOOOOH MY GOOOOOD... THIS DUUDE IS A GENIUS
AND HE TALK LIKE THE N E R D LEWIS SKOLNICK
FROM THE MOOWIE NERDS.. I AM A HAM/AMIGA NERD
MY SELF .. SO GO ""LEWIS """ YOU ROCK BRO.. EVEN LAUGH SAME WAY
love the video - nice flashback of Classic RF Technology.
But yes, as a few others have mentioned, you could work on the every second sentence is a end with laughter. the repeated giggles and laughter is a bit obnoxious since you are trying to do a documentary and only a handful of things you described were actually funny.
The old WFUN in Miami had one of these. I took care of it in 1974 and 1975. And a Gates BC-5B in Tucson before that. Amazing old machines.
2:55 Is the sticky meter the equivalent of the stuck water level meter in The China Syndrome?
70 years old and still running wonder if new junk ever last that long ? the old RCA is nice transmitter, nice unit .
Wow imagine being able to use for CB channel 6 the superbowl channel. Aaaaaudio aaaaudio check check lol😂
I love that 90% of the exposed circuitry would fry you as surely as a fish stick in a toaster oven
Watching as I sit here in a modern AM radio station waiting to load my "carts" for the overnight newscasts.
La Voz de Carabobo 1040 AM, broadcasts from the city of Valencia, Venezuela with a similar Harris 10kw
A most excellent tour, of a most excellent piece of 1950's technology. I know little about transmitters, but am assuming it's audio is plate modulation? I know ham transmitters from the 50's were sometimes screen modulated, and that's why I'm asking. I had a friend who used a Johnson Viking 500 starting using during the early 70s through the early 90s. He wound on occasion operate the 500 with it's cover off in order to enjoy the bright fuchsia Color That was given off by what I believe to be 2x 811's. Thanks for the walkthrough.
More or less, yes. As I understand it, it's a hybrid between plate modulation and Heising modulation.
I have a ham radio amp will put our 2000 watts all day I only run it at about 1200/ 850 at most
12:00 DANGER!!! High voltage
massive power consumption, how do modern transmitters compare?
Was the shag carpet installed for soundproofing 😂