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a video suggestion id love to see is different techniques to make these type of ac hook ups safer. ie. converting to a 3 prong chassis ground plug. ive looked around and have found very little info on this. love your content i learn so much.
So back in the day when they didn't have polarized plugs and connected two pieces of equipment together how did they know it was safe. I.E. connecting the output of a phonograph to this device here. Since the audio cable jacket is tied to the case on both ends if the power cable is flipped on one of the devices then you have a short between equipment. So how did the general public person with no knowledge of electronics keep from frying things.
Paul, I had one of these, back in 1965. I ran a wire, out my bedroom window to my neighbors tree, about 120 feet away. I would load up my 45 record player, with records, and play it into this transmitter for hours, after school. My best friend lived about 5-blocks away, and he would dial it in! Then, one day, it just wouldn’t light up. Stuck it in a box, and mom chucked it, when I was in the USMC. Alas, it was fun while it lasted!
@jimpowell9205 - Semper Fi bro and Merry Christmas! I go back to the good old Radio Shack days, project kits 150 in one etc. My late father, an electronics engineer for USAF 30 years always got me into these type kits etc. Lots of memories with this stuff! To bad your mother tossed it in the garbage. Thanks for your story and service! Semper Fi USMC '75 - '81 OoohRah!
Boy that brings back memories. Built one in the 50s. Had my own radio station in my neighborhood. I'm 73 now. Was talking to one of my neighbors who I hadn't seen for 60 years the other day and she asked me if I remembered being a DJ back then. Amazing this pops up on my internet coincidentally.
I had one when I was a teenager! I am 73 now! My twin brother and I hooked up a long wire antenna and tested the range with a portable radio and were able to get 5 blocks in the neighborhood!!!
I built one of these as a kid. I do remember the last part of the instructions where it says to attach the supplied wire to point X and said "this is your antenna DO NOT EXTEND this wire!" Needles to say the first thing I did was attach to my 100 foot longwire shortwave receive antenna and the second thing I did was walk around several blocks around the neighborhood listening for the signal (I ran a tape recorder into it). Went several blocks, and I learned how to couple the little pocket transistor radio to a telephone pole to bring it in.
Never had a Allied Knight kit transmitter of any kind, but I built a Knight stereo and a Knight Span Master. I am now 73 years old. I built the Span Master in 1962 when I was 16. I still have it ! !
We built a high school "rock radio" station (studio) and fed one of these Knight broadcasters way up in an attic space, near the roof - had about a 1 mile radius in reception. Big dreams back in the 60's !
Mr Carlson, I am not an engineer nor do I know anything about electronics. I simply enjoy watching your content. You are so intelligent. I learn new words every video. Haha. 43 and still learning and entertained. Thanks
Yep, That was the “rig” Dad & I built for my youthful local radio station, albeit I added a long wire, which, as I mentioned in a comment on your post about your Gates Broadcast Xmtr, brought an FCC van cruising my neighborhood, in search of my errant unlicensed station. Knightkits & Heathkits put together on the kitchen table were my electronics “schooling” leading up to ham radio, TV repair, Bourns BioMed bench tech, arcade game tech, then EMI/RFI open field lab test tech with the advent of pc & mainframe computer hardware. An even more beautiful pix of your amazingly organized electronic Garden of Eden-out of camera range, of course, is a workbench covered with caps, resistors, half-breadboarded projects buried in a rat’s nest of spaghetti, smeared with rosin drips & burn marks as the smoke of a well used Weller Station wafts over it all...oh, sorry, I was looking at mine! 73’s, WB6U
WOW. I built this unit in about 1959 0r early 60's. We had hours of fun tricking friends with their own car radios into believing the police were coming thru their AM radio's. While sitting out under the apple tree at a table we had hours of fun letting other neighborhood kids hear themselves on AM radio. Thank you Mr Carlson
My friend built one in1964 and still broadcasts from it ! OMG, I can still remember his license: "Broadcast amplifier 83Y706 meets the FCC restricted radiation requirements under rule 15.204. Wow, how can I remember that?
Another Knight Kit from my youth! I seem to remember "accidentally" connecting one of those up to my 40 metre long-line and...oh, never mind. I also used to drive my mother crazy when she was trying to listen to Arthur Godfrey and I would interject some German polka music from a 78 rpm shellac record. That must have been about 1959.
You rascal you. In 1969 my father and I took a vacation to California from Texas. I had added a rear speakers to the 64 Ford to the am radio. In the crack of the rear seat was a wire splice. Out of San Francisco with my uncle Buster we went to Lake Tahoe. (First time I ever saw a Hemi CUDA) Buster would be singing away and I would touch the wires together. Buster would say Bobby what's wrong with your radio, dad had a funny look I don't know it's never done that. I am still blessed with my father. And my dear Mother. One of my father's stories is farmtown Bangs Texas a gentleman had his own little station played music. No running water no electricity but they had a battery powered receiver. Dad heard Hank Williams seven encores the Grand Ole Opry. We still go back and visit the 300 Acre Farm.
@@radiorick4975 Great stories. We had Sears battery radio in the 1950s and up into the 1960s up in northern Wisconsin. My dad was a professional symphony musician, so no Hank Williams, but the news and Arthur Godfrey, Amos and Andy and Jack Benny. I got my education on that radio. it had an expensive 15 volt dry battery, as big as a cigar box. We also had no running water or electricity and only a pot-bellied wood stove. Life was good then, too.
Nice video. I would like to see you hook It up to a turntable or other source and then see how far it will broadcast into a real radio. I ran a similar device as a dorm radio station in college. Great fun!
Mr Carlson is well versed in all aspects of electronics including vacuum tube and solid state. He seems to have that natural ability to troubleshoot with both logic and gut feelings. He's probably one of the best electronic troubleshooters that I have ever seen. Bravo Mr Carlson..I love your videos!
A tip that I'd like to convey is all the glass tubes have their tube number printed on the side. So if you choose to clean the chassis and dusty tubes it is easy to wipe the tube type off with even a gentle cleaner and a rag. End result a mystery tube. Thank you for making this video and give this old kit some fresh air.
I am old enough to remember that some of the early 7-pin and 9-pin "Noval" based vacuum types had silver plated pins, which was thought to be a good idea, at the time. However, it was found that the silver "migrated" across the glass base of the tube, causing "interesting" leakage problems between pins. The result of that was, when confronted with a "problem" with such eastly tubes, the first thing that a "Service Person" would do was to clean the glass surface between the pins, by rubbing with a cotton cord, or similar. When this problem was discovered, silver plating of the pins was discontinued.
I constructed onee like that way back in 1965 when I was still in high school. It was fun to build but was very careful in operating it. It was AC so it was the chassis was connected to the mains but other than those it was very easy to use.
My brother and I had this unit for our radio stations when we were kids (1965-1972). We hooked up the antenna output to a 20 foot piece of 12 gauge wire and went off to see how far it transmitted. We walked about a mile or two; the signal had drifted over onto a major station so we high-tailed it back and turned it off! Great device and great show today!!
Wow, you guys did just what I did and I think it was the very same year of 1965 when I had my own radio station each afternoon after school. the call letters were WNUT. It was lots of fun getting my classmates to try and tune in.
I am loving this. My first kit. At age 10, I used this kit and was an imaginary DJ to my brother and two sisters. This was followed by a Knight Kit 101 experiments kit, Heathkit IM-13, helping my dad build a Heathkit Shawnee Six, trouble shooting a Collins R-388, then majoring in electrical engineering at Texas A&M. Followed by a career in media production and now as I near retirement I do high res audio engineering tracking, mixing and mastering of pipe organ and jazz performances. All starting with that cute little Knight Kit Broadcaster. 😀
My dad bought me this very Knight Kit when I was about 12 years old. I put it together, and we broadcast to the neighbors radio and my dad told stories to the 7 year old neighbor boy. What fun it was. You brought back a lot of memories. Thank you. I enjoy your explanations; even if most of it is over my head.
As a kid I built one of these too. Had a lot of fun with it which lead to a career in radio-TV broadcasting where I got to play with the big stuff. ;-)
This would be a great little kit for people wanting to get an auxilary source onto a nice old radio that did not have any auxilary input. It could give quite extended life to old radios in the new world. Imagine playing some really nice music through that old radio on the shelf from a modern source with this little thing hiding in the back room somewhere.
Great video. As a kid I built a Radio Shack low power AM transmitter and adjusted the tuning up to the TV channels so I could jam the video of our own TV. We had only one TV and if I jammed the channel my sisters wanted then I would get to watch something better on another channel ! Worked great but eventually I got caught. I guess it became obvious finally as after an argument over what channel was going to be watched I would run upstairs and tune the transmitter until I heard screams of displeasure downstairs 😂.
I had the Ramsey Am Broadcast TX kit, fun to build and use for my local neighbors, they liked listening to me every evening. Miss the closure of Ramsey Kits!
Growing up near Chicago was always torn in my locality between Knight kit and Heath kit. My first kit was a Knight VTVM, saved up all summer 1961 between 8th grade and freshman high school.
I was always interested in electronics. Went to college in 1989 initially to get an AS in electronics. Unfortunately i'm not THAT Mathletic and flunked out. Also, the teachers sucked. They were old at the end of their career and just didn't give a crap. They also couldn't teach in a way that showed you application. I went back for Computer aided design and several years later went back again for plastics. But electronics was always dear to me. 35 years after wanting a Ham radio license I studied and tested directly to General a couple weeks ago. The simple electrical theory rekindled my interest in it. Seeing these videos it's the first time in a long time that things make sense. If I had a teacher like you I probably would have hung with it and had a very different career.
What I want to build Is a tube AM or FM radio kit ,which no one makes any more when I was I my 20,s I found a tube kit on the floor of a old electronics store,it was a tube tuner kit with a vertical manic eye turning, as you tune the radio from right to left the manic eye would move from side to side ,and when it got to a good station the eye would close I have seen any other turning eye like that one ,it had a extra rc connector on the back ,it said in case fm stereo became popular ,I hook my tube tuner to my radio shack quad amp ,and my first wife husband still use it .But the enjoyment I got out of putting together that tube radio. ,I miss so much . I wish someone still made tube radios ,I love the sound ,and the tubes.
Enjoy your videos , I am a Ham and have always loved old radios. Until you hear a tube type radio you don’t know what you are missing I grew up with them such a great sound .
I still have my Knightkit Broadcaster. I built it around 1961. Three of us in our neighborhood used them to "ham" with. I also used it for a guitar amplifier. And I subsequently got my Ham license....56 years now.
What a gem this video is for a person like me who grew up admiring these kits and building a few with my dad. I've loved wires and circuits ever since.
I think the heart of the question at: 7:45 - if you should handle tubes with bare hands, the concern being: does the oils from your fingers create hot spots thus shortening the life span of the tube when the tube undergoes operating temperatures. For instance, you are warned by the manufacturer of quartz lighting fixtures to avoid directly touching the quartz bulb as it will reduce the life of the bulb. However you've answered the question when you stated the glass materials used.
I got one for Christmas in 1975 My sister and I would play news caster and weather report I would be in my room and her in her room Mine worked I was 11 Ended up in the Navy Advanced Electronic Went into Aerospace electronics on the LANTRN , Patriot middle project Then into consumer electronics as an audio video bench tech into teaching now back in the field as a remote service tech in Hospitals and Schools communication Made a life time career out of it Thanks mom and dad
They used these for you to sell your house. You have your board outside with the frequency listed, so that potential buyers could listen to your house description.
Hi mr. Carlson. I wouldn't bother putting in NPO caps because that circuit is inherently unstable. There are many other factors that would cause it to be unstable. Keep in mind that sometimes they have temperature compensated caps to counteract the temperature coefficient of the oscillator coil. And also, the antenna will have a big effect so it's no point in putting real stable caps in there. Just my two cents.
When I was a kid, I connected one lead from my phonograph to the metal cap on the top of a tube of an old radio. I first removed the radio wire that normally was connected to the tube and connected the other lead from my phono. This made my old radio into a transmitter. I could then play my phono and pick up the signal on nearby radios. This was a hit or miss transmitter, I didn’t know really what I was creating. I fell in love with radio at an early age thanks to an uncle who also liked radio.
About 30 years ago we were cleaning out my Grandma's house and I found one of these left behind in my uncle's old bedroom he'd used when he was a kid. I guess I was about 13 at the time and it sparked my interest and I eventually got my ham license. Unfortunately when I went to college, I left all my electronics gear at home with my parents. When I got back several years later, this was one of the pieces missing, along with a lot of other gems my mom probably thought was junk filling up my ham shack in the laundry room! Too bad I sure wish I still had it around! It's probably in a landfill somewhere. Thanks for the video. It was really a treat to see this come up in my feed.
Paul, I've watched this video a couple times now and this time the came to me, " Why doesn't Mr. Carlson build a AM broadcaster like this ... only better" and post it to Patreon!
That device you were holding is a vacuum switch or relay. It is perfect for antenna switching, high voltage switching, or isolating because it has very low capacitive coupling.
Wow did that bring back memories. That was the first transmitter I ever had. I put it in a wooden box and modified it to also be an intercom. I somehow lost the unit over the years but it was the beginnings of my lifelong carrier in TV, Radio and Microwave broadcast RF engineering. Thank you Knight Kit and Mr., C
We had a Knight kit radio broadcaster amplifier when we were little kids. My Dad ordered it from Allied Radio Corporation in August 1962 when the amplifier in his record player broke down, so he ordered this unit and he and I both built it together. He then plugged his record player in this radio broadcaster and he'd listen to his phonograph records through an AM radio. It was fun!
We have cut the cable cord many years ago. These days I spend my tv time watching UA-cam videos. This is one subscription I look forward to new videos. Not an electronic guy at all I just enjoy his projects. I will leave watching Grays Anatomy and or any other net work gibberish to others to watch. I will pop my popcorn and watch Mr. Carlson’s Lab.
@@robertcalkjr.8325 Every episode of How the Universe Works and A Spacetime Odyssey is available for free without ads on ihavenotv.com along with 400 other full length astronomy documentaries, including from the Science channel and a lot of other channels, plus 2500 more on all kinds of other subjects. Did you know there was a research study which showed that children who were shown just two TV ads - and were then asked to choose between spending time with either a mean bully with the toy from the ads, or a nice friendly kid without the toy - invariably chose the bully with the toy?
Alden Zenko No, but I don't believe every "study" that I hear about. I don't want to wear my computer out on TV shows. Also, most of the time I DVR shows and skip past commercials or just mute them if I am watching live. I love remote controls!
When i was 10 years old i built the first piece of electronic gear in my life which was a pair of Knight Kit 3 transistor walkie talkies. I built them with an old Weller soldering gun. They were rated at 100 milliwatts but i doubt they actually made more than 50. Amazingly i learned quite a bit of electronic theory from those kits. They were my introduction to electronics way back in 1961 and sparked my interest in radio. Today i hold an Extra class FCC license and Ive never lost interest in electronics. Thanks for the memory, Paul I look forward to the next excellent video.
MY MOM MAY HAVE MADE THAT 50C5. There was a factory in Norwood Ohio a few miles from here. She LOVED working with those little parts. I recall her telling me as a child and we actually spoke of it a few years ago. She died in April 2017 I have a few little ones around here somewhere. I built my own aprox 300W AM transmitter from parts of schematics from an ARRL handbook in the local library. I used a special order crystal in an army surplus oven, cut for 1610 AM from Jans Crystals, Crystal springs FL. I'm thinking I paid about $10 for that. The rest including Color TV horiz output tubes for the transmitter, x 4 Those were the days, I had a Heath Kit scope to watch the modulation. I was VERY popular around my neighborhood. for about 14 months... I was a bad boy.
m AUSTIN , hope you didn't get in trouble. 😀 Back in the 1960s, a friend of mine did that for about a month. He got a visit from two gentlemen from the FCC, who showed him the "error of his ways." 😀😀😀 Fortunately, he got off only with a warning.
@@jeromewysocki8809 Thank you sir. No I didn't get into trouble. I was about 13 when I started. Ran for 14 months. It was known that they didn't prosecute kids for this. I got a stern speech, made to dissemble the transmitter and they took my crystal. I had a spare but never went on again. That WOULD land you in prison. Not sure how much power. I had 4 x I think 6LQ6 big tube for horiz output with a cap on top for the plate voltage. I only ran about 40% modulation because my audio amp was only about 100w. That was 50 something years ago. The FCC guy was nice. He said they had me on a tracking station near Akron, OH. Had I paid attention in school, I'd have known that Akron is not near Dayton, about 50 miles but near Lake Erie south of Cleveland. My head would have been even bigger. Thanks, the good old days.
the Knight kit AM radio I built in 1963 for a project in electronics shop still works fine. there are few good AM stations anymore and the amount of QRM nowadays is insane compared to the good ole days. I also made a radio by drawing the wire on paper with a soft graphite pencil and clipping the leads for the other components such as I could. mixed results but it did work for proof of concept. there were very few printed circuits as they were too difficult to make then esp. for a school shop. my favorite class. I like you video offering and found it very nostalgic. makes me want to pick up the ole butter knight and blow torch and soldier something up. (the soldering irons we were provided were the large plug in type better suited now for soldering up in sheet metal shop. lol so the butter knife analogy is really accurate. Nail and blowtorch was common. keep this stuff up I love it.
I have a complete 1960's Raytheon Lectron toy set which is Raytheon's only venture into electronic toys. It's comprised of electronic blocks that are magnetic which stick to each other on a metal surface that allow you to quickly make electronic circuits, a radio, a light meter, a noise generator, things of that nature so kids can understand how electronic components work. It's quite ingenious. Would you like to review it?
Thanks I wish you were around 57 years ago when I built this unit! My first kit I was 13 yrs old. I would broadcast local bands from my parents garage! This unit had a s surprisingly great ac carrier signal that would travel down a highway some two miles. Thanks for the great video , it’s a wonder I’m still alive at 70 years old now! I didn’t realize that there was a potential of ac on the chassis. Thank you thank you that’s my baby! I went on to be a commercial dj, then onto radio station general manager
Omg, I built one of these when I was 12. 1958? How cool to see it again. I used it to re-transmit my favorite FM jazz station (KRHM) so I could listen to Miles Davis out in the backyard. Man was I a hepcat kid or what? 😂. Thanks so much Mr. Carlson!
I once made something like this, and it actually worked, but was only able to transmit AM stations, and had to be very close to the radio to work. I then decided to connect a big antenna to it, which got it working up to a few feet away. Also, you look like your in a space station🚀
I'm building one of the reproduction kits now. It comes with an isolation transformer that mounts on the back. When it's done I plan on using it to listen to old radio shows on my 1941 vintage Emerson radio, and partly because it's an easy way to get old radio shows and partly for the weirdness factor it's going to be connected to an Alexa Dot... so I can say "Computer" (the wake word), and Alexa will answer me through an 80 year old radio.
This episode sure brings back memories! I built many Knight-kits (and Heath-kits) in ages past. I didn't build this particular one, but some of my contemporaries copied the schematic, added an RF amp stage, and began broadcasting AM radio, playing 45 rpm records. The signal carried several miles, but had to be retuned when someone accidentally bumped the counter!
Your video brought back some good memories. My father was a radio/television repairman from 1925-1968. I'm pretty sure he had the schematics for every radio and television ever manufactured... and then some. I loved playing in his workshop when I was old enough. My first kit was an FM transmitter built on peg board. Making things neat and orderly was mandatory.
I built one of those as my first kit. I used it as an audio amp with a turntable and speaker . It played my mono Beach Boy albums an an acceptable level and sounded good. I replaced it with a Heathkit stereo vacuum tube amp which served me well. Of course I had no idea it was so dangerous, but everything probably was back then. I still have the albums.
Got mine from allied when i was a kid. my build did not look near as good as that. But it was my first build ever. I learned that caps hold a CHARGE! Did not work first off. It. fell on the floor . I though all was lost. Pluged it in and it Worked ! Thanks for the show. Wish you were around when i was a kid. For some reason i am still alive. Jack Hreha
When my uncle was still around, we made a small Radio receiver and transmitter. Those were the days, this one brought back memories, which is nice. :) I should get it out of storage, clean it up and see if it still works.
Ah, this brings back memories of when I fired up my own AM broadcast station as a teen long ago. Via surplus and for about $5, I'd gotten the LF oscillator accessory that was installed in some WWII ART-13s. It was intended to let that Collins-made HF aircraft transmitter tune down the ship frequencies below the AM broadcast band. Since it tuned into the low end of the broadcast band, that gave me an idea. For modulation, I took an audio output transformer that converted from a high impedance (tube) to a speaker (low). I reversed it, feeding the low impedance speaker output of my SW radio into it and feeding the power for the oscillator through the high impedance winding. For an antenna, I hooked up both sides of the coax feeding my 10-meter beam, so that meant about a 20-foot high vertical. Oh, and I hooked a high-voltage capacitor from a TV between the plate of that oscillator and the antenna, so the antenna wouldn't be hot with about 250 volts. Since this wasn't exactly to FCC regulations, I took two precautions. First, I put it on the air on Christmas Day. Surely, I told myself, they won't be working today. And second, for audio I supplied it with what a local AM station was broadcasting. If anyone tuned it in, they'd wonder why that station was on a different frequency. Then I took off in the family car to see how far I was getting. On one direction, a dry, sandy hill top, it petered out after about five blocks. In the other, with damp soil, it was still strong when I got to a wood almost a mile away. That way, it was probably getting about two miles. Here's what I was using: ----- Low Frequency Coverage and More Accessories - The standard ART-13 transmitter frequency range is from 2.0mc to 18.0mc, however many Navy ATC and T-47/ART-13 transmitters and later USAAF T-47A/ART-13A transmitters were equipped with a plug-in Low Frequency Oscillator (LFO) module that allowed the transmitter to operate from 200kc to 600kc or 200kc to 1500kc (at somewhat reduced power, CW only for electrically short antennae.) Early LFOs had a frequency range of 200kc to 1500kc in six ranges designated as O-16/ART-13, while the later LFOs cover 200kc to 600kc in three ranges and is designated as O-17/ART-13A. The LFO modules used a single 1625 tube. When the LFO is in operation the ART-13 Multiplier section is bypassed and the LFO output directly drives the PA. --- The ART-13 was probably the most beautifully made of the WWII transmitters, as you can see from the interior photos here. www.radioblvd.com/art13.htm
We had a couple of these back in the mid-60s; in fact, I wired one myself. We were required to use an antenna of 10 feet or less. We didn't have any fancy modulation analyzer as shown in this video. Sure wish I did, though! Anyway, we fed our audio not to the XTAL or MAG ports, but from another 8-ohm audio amp which we connected via zip cord to the Knight-Kit's audio transformer terminals. I didn't discover this myself, another genius of a hobbyist put me on to it. It worked great for our neighborhood radio station, for which we had a home-brew console, a couple of turntables, a mike and a reel-to-reel recorder. The Knight-Kit was on the second floor of my friend's house, and the vertically-polarized, fully-extended telescoping auto radio antenna was mounted outside the house. The studio was in the basement of the house, which we were able to do because we ran zip cord from our audio amp to the Knight-Kit's xfmr terminals. "Those were the days, my friend...."
@@auspicioustoot The American Radio Relay League is the formal organization and outreach program for Amateur Radio operators (Ham Radio) and electronics enthusiasts in general. The ARRL handbook is an indispensable guide to learn all about amateur radio and electronics. You can find out more at www.arrl.org/
Years ago, I built a Ramsey FM stereo radio transmitter. I didn't know what to expect but the Ramsey transmitter can transmit a high fidelity stereo signal about a half mile with the small antenna that comes with the kit. You could probably transmit a better signal with a better external antenna but I have never tried it.
I was surprised to see your scope showing the demodulated signal and not the RF envelope. Old AM guy here. I'm used to watching envelopes. BTW, I'm so old that whenever I see an N-channel FET I imagine it as a triode. 😊 Another well done, informative video. Thanks and 73!
Can't blame you for that. From a teaching / understanding electronics perspective the inner workings of tubes are easier to understand than unipolar or bipolar transistors and for some applications tubes are having near-perfect properties, all good for getting started. What I don't like about tubes, in particular power tubes are the voltages in the kilovolt range near the knuckles while doing adjustments or heat that puts a sauna to the shame ...
@@ralfbaechle Yes, semiconductors take some teaching. But once you understand the theory about how a semiconductor works, it is no more difficult to learn about transistors than it is to learn about valves.
OMG I had this exact transmitter when i was a kid! We got it at a garage sale. I remember the seller saying "oh , oh thats trouble" picking on me for wanting it at 10 years old
@@ricande nope lol we lived 40 acres in the middle of nowhere. But that transmitter worked great. Dont remember what ended up happening to it. Maybe still at my parents house
Believe me your mother threw that “junk” away when you were away in the ( fill in the blank). Military College First out of town job Your own entry here…
I love your very clear explanation. I have refurbished that kind of stuff along with jukeboxes since the 80s, and I would have liked to have someone who explained things that clearly when I started to be interested in electronics.
Items such as what you presented here, can be found at Ham radios swap meets. I like to pick up such items as they probably do not work, and see if I can make them work. Some of my favorites are Heathkits of all kind, as these items where all built by someone, and the manuals for them can usually be found on the Internet. I like the simple kits, as they are fun and easy for me to trouble shoot and they maybe useful in my Ham radio. Thanks again for a great job of explaining how all of this "old stuff" works!
I made an AM transmitter for my grade 8 science project, the design was from Howard Sam's "Having fun with Transistors". It used 2 2n107 germanium transistors and I had to wind my own antenna coil. It had a range of 6 feet and appeared on 7 different points on the tuner dial.
Back in the day, Stancor and Triad were the big dogs on the street for transformers and could easily run up to 1/2 the cost of the kits or more, so line voltage design, while "tasty", allowed a fairly affordable build for the hobbyist kid- like I was. My best friend and I would head to the dump about once a month and harvest components from old t.v.'s and radios we dug up for our reuse. Once we took a bucket of tubes to the local supermarket that had one of those courtesy tube testers there, but we were thrown out after about a half- hour of using their electricity and not buying any of their tubes. ☺ Damn, those were fun times for a coupla entrepreneurs!
Wow - I went back to my own little example. Replaced C-7, the 470pf - I had no suitable mono caps, so I used a 470pf silver-mica. It's as stable as the transistor radio I'm using to 'preview' it. It used to drift for about 20 minutes before it warmed up. Thanks!
A relay, actuated by the effect of a magnetic field developed by the current in its energizing coil(s). There used to be 4 manufacturers who built this device, now there are still 3 offering it to the market. Originally, this device was used by the military (like many of those things). BTW, Paul, next time please hide the part number on the device. This one was easy to read and google offered the answer right away. :)
I've got some old Allied Electronics catalogs from the late 50s and early 60s I found in my cousins basement. Great stuff to look at and reminisce. My dad had a knight reel to reel tape recorder when he was a teen.
By the way, I believe every video you publish on youtube, Just like you, I am a serviceman technician here in our locality, I restore, repair, and even install electronic equipment as what my clients wants me to do.
I borrowed one of those from a friend's father. I am so guilty of taking parts from it. The FCC always has had over kill rules. The real technique here is a short antenna with a tuner and some ground plane. You need adjust your scope to get in into envelope mode. Then you can guess modulation percentages.
Wow - I remember every detail from age 9 when it was a brand new kit; I wish I had kept it. ( I built TWO of them! Worked, but I never could get the range to go beyond a few houses. RF was a complete mystery to me as I experimented with various antenna "wires" and overworked that slot on the tuning capacitor. Unsupervised 110 VAC construction by a kid... good old days! lol)
I have not built a tube type, but I did build a Crystal receiver with the old bare crystal and cat whisker and about 150 feet of antennae with my dad when I was about 9 and it worked! but I think we were smarter back then, kids now days they would have the "stick the wire in your butt and plug it in challenge" HAHAHA
@@kenseastrand7428 YES! I'm happy to hear that (back then) you found the exact sweet spot in that bare crystal. A "modern" germanium glass diode did not produce the same thrill for the next generation... And today, it's got a touch screen.
Thx Mr. Carlson ! Your explanations are both clear and concise and entertaining often ! I wish I had decided to become an instructor years ago as I think I would have followed your lead. My instructors were quite dry most of the time and thus quelled most of my original desire to learn electronics as originally intended. I look forward to following your coursework. The materials of CREI were my original material obtained and it was quite good. They were sold to another company and quickly went downhill , dang shame as many followed them at the time.
If that kit was available in the UK the chassis would have to be earthed (grounded), especially as it is a transformer-less circuit. Thinking about it, it would have a mains transformer to improve safety and use 6.3 volt heater (filament) valves (tubes). The UK and Europe have 240 volts mains, so dropping the filament voltage would be less easy.
I built a KnightKit Phono Oscillator in 1964 and actually Increased Output and made it Crystal Controlled, 1600 KC. I lived in Benton, AR. on a Large Lot, on River Street, and never got a complaint. It was a simple kit with excellent Schemetic and Pictoral Diagram. I was 14 Years old.
Knight kit had some pretty cool products. When I was 5 years old my father built a C 27. It was a unique two channel CB. It had a VFO so you could listen to all the channels you didn't have. His callsign began with the number 5. The ITU put the kibosh on that so the FCC switch to the letter K as a prefix.
This was one of my first electronic projects at age 12. I read about the 12 inch antenna restriction, but it worked so much better attached to the families' steam heating system. We broadcast about 2 miles. Had so much fun. I never figured out why that even worked, because the steam pipes went into the cellar, and hooked to the boiler which had grounded water pipes. Andy
I can remember one Christmas about 1950 when my older brothers had this device. They imitated the "HADACOL" adverstisment. The All american 5 were also called an AC/DC radios. People in the rural area with no ac could but batteries to add up to 120 Volts and have a radio.
I could really see myself using this in my teens. I used a really crude Walkie talkie setup and for longer transmissions a mobile. This was when Mercury released a free 6pm-6am tariff. Man I was wondering what the blue & black device was doing, displaying random numbers. Then I realised it was my phone's voltage.
My brother and I had something very similar to this back in the 70's. It was a 7 or 9watt AM broadcast amp. We would broadcast our radio station WAMAMFM through out our neighborhood. I'll never forget the fun we had. Sometimes my brother would walk up to Mr. Doughnuts at the end of our street to buy cigarettes from the vending machine there for 45¢ and he'd have his transistor radio with him to check our signal strength while I would broadcast. I'd broadcast what kind of doughnut I'd want him to bring home and would have to promise over the air to pay him back. It was sooo cool when he brought home the right flavor doughnut.
I never knew there were that many young guys like me that loved to “experiment” making our own broadcast stations. Later on I bought an FM kit and supposedly it had a limited range. I was able to pump out a signal for about a half mile or so. Didn’t have a PLL so the signal would drift. But it was fun.
Oh man, am I glad I watched this one! Very glad you pulled out the schematic and went over it with us. I've mentioned before that I have a guitar amplifier project I messed up in my youth. A decade or more later and it is time to finally get around to correcting it.
Lafayette Radio made these AM broadcasters also--and in fully built form. They continuously but slowly would drift off frequency--even after being on for 5 or 6 hours--requiring listeners to retune every 15 minutes or so. But for $5, the broadcasters still were a good deal and lots of fun.
An interesting video. I had not heard of this device. In my ham career I've played around with Knight Kit transmitters. AM radio, hmmm I may or may not have "accidentally" warped the tuning of my Viking Valiant's 160 Meter vfo into the top end of the broadcast band.
Ok, I'll be the gumby to say it. Mr Carlson looks like a very young version of the doc. This is really episode 4 where he's stuck in 2020 and misses his childhood transmitter. And, yes the radios RF output is 1.21GW.
I wonder how many youths used those little home weather stations in combination with these Knight Kits to provide accurate extremely local current weather conditions.
Nice review of this transmitter. I saved one of these from the trash. It is the earliest model of Knight kit broadcaster that did not have a bottom cover. They must have felt that who ever built it would keep their fingers out of it. After a few years they did come out with the model you have.
To learn electronics in a different and effective way, and also get access to my personal electronic designs and inventions, click here: www.patreon.com/MrCarlsonsLab
a video suggestion id love to see is different techniques to make these type of ac hook ups safer. ie. converting to a 3 prong chassis ground plug. ive looked around and have found very little info on this. love your content i learn so much.
@@xcreeperify i agree that would be highly useable!!!
I love your videos! I just became a patreon this morning. keep up the good work!
So back in the day when they didn't have polarized plugs and connected two pieces of equipment together how did they know it was safe. I.E. connecting the output of a phonograph to this device here. Since the audio cable jacket is tied to the case on both ends if the power cable is flipped on one of the devices then you have a short between equipment. So how did the general public person with no knowledge of electronics keep from frying things.
Excellent audio quality!
Paul, I had one of these, back in 1965. I ran a wire, out my bedroom window to my neighbors tree, about 120 feet away. I would load up my 45 record player, with records, and play it into this transmitter for hours, after school. My best friend lived about 5-blocks away, and he would dial it in! Then, one day, it just wouldn’t light up. Stuck it in a box, and mom chucked it, when I was in the USMC. Alas, it was fun while it lasted!
@jimpowell9205 - Semper Fi bro and Merry Christmas! I go back to the good old Radio Shack days, project kits 150 in one etc. My late father, an electronics engineer for USAF 30 years always got me into these type kits etc. Lots of memories with this stuff! To bad your mother tossed it in the garbage. Thanks for your story and service! Semper Fi USMC '75 - '81 OoohRah!
@@JohnPiperBoots I’m older………..67 - 71
Boy that brings back memories. Built one in the 50s. Had my own radio station in my neighborhood. I'm 73 now. Was talking to one of my neighbors who I hadn't seen for 60 years the other day and she asked me if I remembered being a DJ back then. Amazing this pops up on my internet coincidentally.
I had one when I was a teenager! I am 73 now! My twin brother and I hooked up a long wire antenna and tested the range with a portable radio and were able to get 5 blocks in the neighborhood!!!
Zback in the 50s we were told to keep your left hand in your back pocket. While working on these. Ac dc radios.
I built one of these as a kid. I do remember the last part of the instructions where it says to attach the supplied wire to point X and said "this is your antenna DO NOT EXTEND this wire!" Needles to say the first thing I did was attach to my 100 foot longwire shortwave receive antenna and the second thing I did was walk around several blocks around the neighborhood listening for the signal (I ran a tape recorder into it). Went several blocks, and I learned how to couple the little pocket transistor radio to a telephone pole to bring it in.
Never had a Allied Knight kit transmitter of any kind, but I built a Knight stereo and a Knight Span Master. I am now 73 years old. I built the Span Master in 1962 when I was 16. I still have it ! !
I did too, around 1961. Also helped a friend build a Space Spanner.
Span Master Cardboardy cabinet model; High Voltage on headphone connector ! ! !
We built a high school "rock radio" station (studio) and fed one of these Knight broadcasters way up in an attic space, near the roof - had about a 1 mile radius in reception. Big dreams back in the 60's !
Mr Carlson, I am not an engineer nor do I know anything about electronics. I simply enjoy watching your content. You are so intelligent. I learn new words every video. Haha. 43 and still learning and entertained. Thanks
Yep, That was the “rig” Dad & I built for my youthful local radio station, albeit I added a long wire, which, as I mentioned in a comment on your post about your Gates Broadcast Xmtr, brought an FCC van cruising my neighborhood, in search of my errant unlicensed station. Knightkits & Heathkits put together on the kitchen table were my electronics “schooling” leading up to ham radio, TV repair, Bourns BioMed bench tech, arcade game tech, then EMI/RFI open field lab test tech with the advent of pc & mainframe computer hardware.
An even more beautiful pix of your amazingly organized electronic Garden of Eden-out of camera range, of course, is a workbench covered with caps, resistors, half-breadboarded projects buried in a rat’s nest of spaghetti, smeared with rosin drips & burn marks as the smoke of a well used Weller Station wafts over it all...oh, sorry, I was looking at mine!
73’s, WB6U
Had something like this when I was a kid and on a good night it would broadcast 21/2 to 3 blocks ! Good times !
WOW. I built this unit in about 1959 0r early 60's. We had hours of fun tricking friends with their own car radios into believing the police were coming thru their AM radio's. While sitting out under the apple tree at a table we had hours of fun letting other neighborhood kids hear themselves on AM radio. Thank you Mr Carlson
My friend built one in1964 and still broadcasts from it ! OMG, I can still remember his license: "Broadcast amplifier 83Y706 meets the FCC restricted radiation requirements under rule 15.204. Wow, how can I remember that?
Another Knight Kit from my youth! I seem to remember "accidentally" connecting one of those up to my 40 metre long-line and...oh, never mind. I also used to drive my mother crazy when she was trying to listen to Arthur Godfrey and I would interject some German polka music from a 78 rpm shellac record. That must have been about 1959.
Also metal clothes lines make great (and long) antennas ;D
@@BillAnt LOL!!
You rascal you. In 1969 my father and I took a vacation to California from Texas. I had added a rear speakers to the 64 Ford to the am radio. In the crack of the rear seat was a wire splice. Out of San Francisco with my uncle Buster we went to Lake Tahoe. (First time I ever saw a Hemi CUDA) Buster would be singing away and I would touch the wires together. Buster would say Bobby what's wrong with your radio, dad had a funny look I don't know it's never done that. I am still blessed with my father. And my dear Mother. One of my father's stories is farmtown Bangs Texas a gentleman had his own little station played music. No running water no electricity but they had a battery powered receiver. Dad heard Hank Williams seven encores the Grand Ole Opry. We still go back and visit the 300 Acre Farm.
@@radiorick4975 Great stories. We had Sears battery radio in the 1950s and up into the 1960s up in northern Wisconsin. My dad was a professional symphony musician, so no Hank Williams, but the news and Arthur Godfrey, Amos and Andy and Jack Benny. I got my education on that radio. it had an expensive 15 volt dry battery, as big as a cigar box. We also had no running water or electricity and only a pot-bellied wood stove. Life was good then, too.
Nice video. I would like to see you hook
It up to a turntable or other source and then see how far it will broadcast into a real radio. I ran a similar device as a dorm radio station in college. Great fun!
For such a minimalistic bit of kit, I'm impressed. Just look at that signal quality on that thing !!!!! Wow
Mr Carlson is well versed in all aspects of electronics including vacuum tube and solid state. He seems to have that natural ability to troubleshoot with both logic and gut feelings. He's probably one of the best electronic troubleshooters that I have ever seen. Bravo Mr Carlson..I love your videos!
A tip that I'd like to convey is all the glass tubes have their tube number printed on the side. So if you choose to clean the chassis and dusty tubes it is easy to wipe the tube type off with even a gentle cleaner and a rag. End result a mystery tube. Thank you for making this video and give this old kit some fresh air.
I am old enough to remember that some of the early 7-pin and 9-pin "Noval" based vacuum types had silver plated pins, which was thought to be a good idea, at the time.
However, it was found that the silver "migrated" across the glass base of the tube, causing "interesting" leakage problems between pins.
The result of that was, when confronted with a "problem" with such eastly tubes, the first thing that a "Service Person" would do was to clean the glass surface between the pins, by rubbing with a cotton cord, or similar.
When this problem was discovered, silver plating of the pins was discontinued.
I constructed onee like that way back in 1965 when I was still in high school. It was fun to build but was very careful in operating it. It was AC so it was the chassis was connected to the mains but other than those it was very easy to use.
My brother and I had this unit for our radio stations when we were kids (1965-1972). We hooked up the antenna output to a 20 foot piece of 12 gauge wire and went off to see how far it transmitted. We walked about a mile or two; the signal had drifted over onto a major station so we high-tailed it back and turned it off! Great device and great show today!!
Wow, you guys did just what I did and I think it was the very same year of 1965 when I had my own radio station each afternoon after school. the call letters were WNUT. It was lots of fun getting my classmates to try and tune in.
I am loving this. My first kit. At age 10, I used this kit and was an imaginary DJ to my brother and two sisters. This was followed by a Knight Kit 101 experiments kit, Heathkit IM-13, helping my dad build a Heathkit Shawnee Six, trouble shooting a Collins R-388, then majoring in electrical engineering at Texas A&M. Followed by a career in media production and now as I near retirement I do high res audio engineering tracking, mixing and mastering of pipe organ and jazz performances. All starting with that cute little Knight Kit Broadcaster. 😀
Thanks for sharing your story Gordon!
Appointment today?
You're making my life more fun just listening to you!
My dad bought me this very Knight Kit when I was about 12 years old. I put it together, and we broadcast to the neighbors radio and my dad told stories to the 7 year old neighbor boy. What fun it was. You brought back a lot of memories. Thank you. I enjoy your explanations; even if most of it is over my head.
Jim, that's awesome. I loved opening electronic kits when i was that age, but something about radio and being on air yourself was really cool
This kit could probably transmit about about 1/4-1/2 mile LOS? not bad at all
My very first electronic kit when I was a kid in the 60's! Thank you so much for that nostalgic trip! Brings back a lot of memories!
Glad you enjoyed it Ken!
As a kid I built one of these too. Had a lot of fun with it which lead to a career in radio-TV broadcasting where I got to play with the big stuff. ;-)
This would be a great little kit for people wanting to get an auxilary source onto a nice old radio that did not have any auxilary input.
It could give quite extended life to old radios in the new world. Imagine playing some really nice music through that old radio on the shelf from a modern source with this little thing hiding in the back room somewhere.
My comments to show support for your Videos are as follows. *Big Thumbs Up*
Great video. As a kid I built a Radio Shack low power AM transmitter and adjusted the tuning up to the TV channels so I could jam the video of our own TV. We had only one TV and if I jammed the channel my sisters wanted then I would get to watch something better on another channel ! Worked great but eventually I got caught. I guess it became obvious finally as after an argument over what channel was going to be watched I would run upstairs and tune the transmitter until I heard screams of displeasure downstairs 😂.
I had the Ramsey Am Broadcast TX kit, fun to build and use for my local neighbors, they liked listening to me every evening. Miss the closure of Ramsey Kits!
Growing up near Chicago was always torn in my locality between Knight kit and Heath kit.
My first kit was a Knight VTVM, saved up all summer 1961 between 8th grade and freshman high school.
I was always interested in electronics. Went to college in 1989 initially to get an AS in electronics. Unfortunately i'm not THAT Mathletic and flunked out. Also, the teachers sucked. They were old at the end of their career and just didn't give a crap. They also couldn't teach in a way that showed you application. I went back for Computer aided design and several years later went back again for plastics. But electronics was always dear to me. 35 years after wanting a Ham radio license I studied and tested directly to General a couple weeks ago. The simple electrical theory rekindled my interest in it. Seeing these videos it's the first time in a long time that things make sense. If I had a teacher like you I probably would have hung with it and had a very different career.
What I want to build Is a tube AM or FM radio kit ,which no one makes any more when I was I my 20,s I found a tube kit on the floor of a old electronics store,it was a tube tuner kit with a vertical manic eye turning, as you tune the radio from right to left the manic eye would move from side to side ,and when it got to a good station the eye would close I have seen any other turning eye like that one ,it had a extra rc connector on the back ,it said in case fm stereo became popular ,I hook my tube tuner to my radio shack quad amp ,and my first wife husband still use it .But the enjoyment I got out of putting together that tube radio. ,I miss so much . I wish someone still made tube radios ,I love the sound ,and the tubes.
Enjoy your videos , I am a Ham and have always loved old radios. Until you hear a tube type radio you don’t know what you are missing I grew up with them such a great sound .
I still have my Knightkit Broadcaster. I built it around 1961. Three of us in our neighborhood used them to "ham" with. I also used it for a guitar amplifier. And I subsequently got my Ham license....56 years now.
Are you operating these days? I have a tech license, but am crrently taking a break.
What a gem this video is for a person like me who grew up admiring these kits and building a few with my dad. I've loved wires and circuits ever since.
I think the heart of the question at: 7:45 - if you should handle tubes with bare hands, the concern being: does the oils from your fingers create hot spots thus shortening the life span of the tube when the tube undergoes operating temperatures. For instance, you are warned by the manufacturer of quartz lighting fixtures to avoid directly touching the quartz bulb as it will reduce the life of the bulb. However you've answered the question when you stated the glass materials used.
I got one for Christmas in 1975
My sister and I would play news caster and weather report
I would be in my room and her in her room
Mine worked I was 11
Ended up in the Navy
Advanced Electronic
Went into Aerospace electronics on the LANTRN , Patriot middle project
Then into consumer electronics as an audio video bench tech into teaching now back in the field as a remote service tech in Hospitals and Schools communication
Made a life time career out of it
Thanks mom and dad
Great! I built the Graymark broadcaster kit in High School electrical shop in the early 70's. It used a pair of 50C5s and a 12AV6 if I remember.
They used these for you to sell your house. You have your board outside with the frequency listed, so that potential buyers could listen to your house description.
Hi mr. Carlson. I wouldn't bother putting in NPO caps because that circuit is inherently unstable. There are many other factors that would cause it to be unstable. Keep in mind that sometimes they have temperature compensated caps to counteract the temperature coefficient of the oscillator coil. And also, the antenna will have a big effect so it's no point in putting real stable caps in there. Just my two cents.
When I was a kid, I connected one lead from my phonograph to the metal cap on the top of a tube of an old radio. I first removed the radio wire that normally was connected to the tube and connected the other lead from my phono. This made my old radio into a transmitter. I could then play my phono and pick up the signal on nearby radios. This was a hit or miss transmitter, I didn’t know really what I was creating. I fell in love with radio at an early age thanks to an uncle who also liked radio.
About 30 years ago we were cleaning out my Grandma's house and I found one of these left behind in my uncle's old bedroom he'd used when he was a kid. I guess I was about 13 at the time and it sparked my interest and I eventually got my ham license. Unfortunately when I went to college, I left all my electronics gear at home with my parents. When I got back several years later, this was one of the pieces missing, along with a lot of other gems my mom probably thought was junk filling up my ham shack in the laundry room! Too bad I sure wish I still had it around! It's probably in a landfill somewhere. Thanks for the video. It was really a treat to see this come up in my feed.
Paul, I've watched this video a couple times now and this time the came to me, " Why doesn't Mr. Carlson build a AM broadcaster like this ... only better" and post it to Patreon!
That device you were holding is a vacuum switch or relay. It is perfect for antenna switching, high voltage switching, or isolating because it has very low capacitive coupling.
Wow did that bring back memories. That was the first transmitter I ever had. I put it in a wooden box and modified it to also be an intercom. I somehow lost the unit over the years but it was the beginnings of my lifelong carrier in TV, Radio and Microwave broadcast RF engineering. Thank you Knight Kit and Mr., C
We had a Knight kit radio broadcaster amplifier when we were little kids. My Dad ordered it from Allied Radio Corporation in August 1962 when the amplifier in his record player broke down, so he ordered this unit and he and I both built it together. He then plugged his record player in this radio broadcaster and he'd listen to his phonograph records through an AM radio. It was fun!
We have cut the cable cord many years ago. These days I spend my tv time watching UA-cam videos. This is one subscription I look forward to new videos. Not an electronic guy at all I just enjoy his projects. I will leave watching Grays Anatomy and or any other net work gibberish to others to watch. I will pop my popcorn and watch Mr. Carlson’s Lab.
There are other stuff on cable, you know. I am multitasking and watching the Science channel right now about supernovas and other good stuff!
@@robertcalkjr.8325 Every episode of How the Universe Works and A Spacetime Odyssey is available for free without ads on ihavenotv.com along with 400 other full length astronomy documentaries, including from the Science channel and a lot of other channels, plus 2500 more on all kinds of other subjects.
Did you know there was a research study which showed that children who were shown just two TV ads - and were then asked to choose between spending time with either a mean bully with the toy from the ads, or a nice friendly kid without the toy - invariably chose the bully with the toy?
Alden Zenko No, but I don't believe every "study" that I hear about. I don't want to wear my computer out on TV shows. Also, most of the time I DVR shows and skip past commercials or just mute them if I am watching live. I love remote controls!
When i was 10 years old i built the first piece of electronic gear in my life which was a pair of Knight Kit 3 transistor walkie talkies. I built them with an old Weller soldering gun. They were rated at 100 milliwatts but i doubt they actually made more than 50. Amazingly i learned quite a bit of electronic theory from those kits. They were my introduction to electronics way back in 1961 and sparked my interest in radio. Today i hold an Extra class FCC license and Ive never lost interest in electronics. Thanks for the memory, Paul I look forward to the next excellent video.
MY MOM MAY HAVE MADE THAT 50C5. There was a factory in Norwood Ohio a few miles from here. She LOVED working with those little parts. I recall her telling me as a child and we actually spoke of it a few years ago. She died in April 2017 I have a few little ones around here somewhere. I built my own aprox 300W AM transmitter from parts of schematics from an ARRL handbook in the local library. I used a special order crystal in an army surplus oven, cut for 1610 AM from Jans Crystals, Crystal springs FL. I'm thinking I paid about $10 for that. The rest including Color TV horiz output tubes for the transmitter, x 4 Those were the days, I had a Heath Kit scope to watch the modulation. I was VERY popular around my neighborhood. for about 14 months... I was a bad boy.
m AUSTIN , hope you didn't get in trouble. 😀 Back in the 1960s, a friend of mine did that for about a month. He got a visit from two gentlemen from the FCC, who showed him the "error of his ways." 😀😀😀 Fortunately, he got off only with a warning.
@@jeromewysocki8809 Thank you sir. No I didn't get into trouble. I was about 13 when I started. Ran for 14 months. It was known that they didn't prosecute kids for this. I got a stern speech, made to dissemble the transmitter and they took my crystal. I had a spare but never went on again. That WOULD land you in prison. Not sure how much power. I had 4 x I think 6LQ6 big tube for horiz output with a cap on top for the plate voltage. I only ran about 40% modulation because my audio amp was only about 100w. That was 50 something years ago. The FCC guy was nice. He said they had me on a tracking station near Akron, OH. Had I paid attention in school, I'd have known that Akron is not near Dayton, about 50 miles but near Lake Erie south of Cleveland. My head would have been even bigger. Thanks, the good old days.
the Knight kit AM radio I built in 1963 for a project in electronics shop still works fine. there are few good AM stations anymore and the amount of QRM nowadays is insane compared to the good ole days. I also made a radio by drawing the wire on paper with a soft graphite pencil and clipping the leads for the other components such as I could. mixed results but it did work for proof of concept. there were very few printed circuits as they were too difficult to make then esp. for a school shop. my favorite class. I like you video offering and found it very nostalgic. makes me want to pick up the ole butter knight and blow torch and soldier something up. (the soldering irons we were provided were the large plug in type better suited now for soldering up in sheet metal shop. lol so the butter knife analogy is really accurate. Nail and blowtorch was common. keep this stuff up I love it.
Doesn't matter how many times I see Mr. Carlson's equipment room I am always in awe
Free Saxon same
It looks like a frickin spaceship
I have a complete 1960's Raytheon Lectron toy set which is Raytheon's only venture into electronic toys. It's comprised of electronic blocks that are magnetic which stick to each other on a metal surface that allow you to quickly make electronic circuits, a radio, a light meter, a noise generator, things of that nature so kids can understand how electronic components work. It's quite ingenious. Would you like to review it?
Thanks I wish you were around 57 years ago when I built this unit! My first kit I was 13 yrs old. I would broadcast local bands from my parents garage! This unit had a s surprisingly great ac carrier signal that would travel down a highway some two miles. Thanks for the great video , it’s a wonder I’m still alive at 70 years old now! I didn’t realize that there was a potential of ac on the chassis. Thank you thank you that’s my baby! I went on to be a commercial dj, then onto radio station general manager
Omg, I built one of these when I was 12. 1958? How cool to see it again. I used it to re-transmit my favorite FM jazz station (KRHM) so I could listen to Miles Davis out in the backyard. Man was I a hepcat kid or what? 😂. Thanks so much Mr. Carlson!
I once made something like this, and it actually worked, but was only able to transmit AM stations, and had to be very close to the radio to work. I then decided to connect a big antenna to it, which got it working up to a few feet away. Also, you look like your in a space station🚀
I'm building one of the reproduction kits now. It comes with an isolation transformer that mounts on the back.
When it's done I plan on using it to listen to old radio shows on my 1941 vintage Emerson radio, and partly because it's an easy way to get old radio shows and partly for the weirdness factor it's going to be connected to an Alexa Dot... so I can say "Computer" (the wake word), and Alexa will answer me through an 80 year old radio.
This episode sure brings back memories! I built many Knight-kits (and Heath-kits) in ages past. I didn't build this particular one, but some of my contemporaries copied the schematic, added an RF amp stage, and began broadcasting AM radio, playing 45 rpm records. The signal carried several miles, but had to be retuned when someone accidentally bumped the counter!
Your video brought back some good memories.
My father was a radio/television repairman from 1925-1968. I'm pretty sure he had the schematics for every radio and television ever manufactured... and then some. I loved playing in his workshop when I was old enough. My first kit was an FM transmitter built on peg board. Making things neat and orderly was mandatory.
I built one of those as my first kit. I used it as an audio amp with a turntable and speaker . It played my mono Beach Boy albums an an acceptable level and sounded good. I replaced it with a Heathkit stereo vacuum tube amp which served me well. Of course I had no idea it was so dangerous, but everything probably was back then. I still have the albums.
Got mine from allied when i was a kid. my build did not look near as good as that. But it was my first build ever. I learned that caps hold a CHARGE! Did not work first off. It. fell on the floor . I though all was lost. Pluged it in and it Worked ! Thanks for the show. Wish you were around when i was a kid. For some reason i am still alive. Jack Hreha
When my uncle was still around, we made a small Radio receiver and transmitter. Those were the days, this one brought back memories, which is nice. :) I should get it out of storage, clean it up and see if it still works.
Ah, this brings back memories of when I fired up my own AM broadcast station as a teen long ago. Via surplus and for about $5, I'd gotten the LF oscillator accessory that was installed in some WWII ART-13s. It was intended to let that Collins-made HF aircraft transmitter tune down the ship frequencies below the AM broadcast band. Since it tuned into the low end of the broadcast band, that gave me an idea.
For modulation, I took an audio output transformer that converted from a high impedance (tube) to a speaker (low). I reversed it, feeding the low impedance speaker output of my SW radio into it and feeding the power for the oscillator through the high impedance winding. For an antenna, I hooked up both sides of the coax feeding my 10-meter beam, so that meant about a 20-foot high vertical. Oh, and I hooked a high-voltage capacitor from a TV between the plate of that oscillator and the antenna, so the antenna wouldn't be hot with about 250 volts.
Since this wasn't exactly to FCC regulations, I took two precautions. First, I put it on the air on Christmas Day. Surely, I told myself, they won't be working today. And second, for audio I supplied it with what a local AM station was broadcasting. If anyone tuned it in, they'd wonder why that station was on a different frequency.
Then I took off in the family car to see how far I was getting. On one direction, a dry, sandy hill top, it petered out after about five blocks. In the other, with damp soil, it was still strong when I got to a wood almost a mile away. That way, it was probably getting about two miles.
Here's what I was using:
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Low Frequency Coverage and More Accessories - The standard ART-13 transmitter frequency range is from 2.0mc to 18.0mc, however many Navy ATC and T-47/ART-13 transmitters and later USAAF T-47A/ART-13A transmitters were equipped with a plug-in Low Frequency Oscillator (LFO) module that allowed the transmitter to operate from 200kc to 600kc or 200kc to 1500kc (at somewhat reduced power, CW only for electrically short antennae.) Early LFOs had a frequency range of 200kc to 1500kc in six ranges designated as O-16/ART-13, while the later LFOs cover 200kc to 600kc in three ranges and is designated as O-17/ART-13A. The LFO modules used a single 1625 tube. When the LFO is in operation the ART-13 Multiplier section is bypassed and the LFO output directly drives the PA.
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The ART-13 was probably the most beautifully made of the WWII transmitters, as you can see from the interior photos here.
www.radioblvd.com/art13.htm
We had a couple of these back in the mid-60s; in fact, I wired one myself. We were required to use an antenna of 10 feet or less. We didn't have any fancy modulation analyzer as shown in this video. Sure wish I did, though! Anyway, we fed our audio not to the XTAL or MAG ports, but from another 8-ohm audio amp which we connected via zip cord to the Knight-Kit's audio transformer terminals. I didn't discover this myself, another genius of a hobbyist put me on to it. It worked great for our neighborhood radio station, for which we had a home-brew console, a couple of turntables, a mike and a reel-to-reel recorder. The Knight-Kit was on the second floor of my friend's house, and the vertically-polarized, fully-extended telescoping auto radio antenna was mounted outside the house. The studio was in the basement of the house, which we were able to do because we ran zip cord from our audio amp to the Knight-Kit's xfmr terminals. "Those were the days, my friend...."
Dude, you're the living ARRL handbook! Great video and fun teardown!
Lance Emil MY GOD YOU’RE RIGHT! He’s 🖖!
What’s that?
@@auspicioustoot The American Radio Relay League is the formal organization and outreach program for Amateur Radio operators (Ham Radio) and electronics enthusiasts in general. The ARRL handbook is an indispensable guide to learn all about amateur radio and electronics. You can find out more at www.arrl.org/
Years ago, I built a Ramsey FM stereo radio transmitter. I didn't know what to expect but the Ramsey transmitter can transmit a high fidelity stereo signal about a half mile with the small antenna that comes with the kit. You could probably transmit a better signal with a better external antenna but I have never tried it.
I was surprised to see your scope showing the demodulated signal and not the RF envelope. Old AM guy here. I'm used to watching envelopes.
BTW, I'm so old that whenever I see an N-channel FET I imagine it as a triode. 😊
Another well done, informative video. Thanks and 73!
I tend to think of it more as a pentode (without the screen grid) because of the high drain resistance.
Can't blame you for that. From a teaching / understanding electronics perspective the inner workings of tubes are easier to understand than unipolar or bipolar transistors and for some applications tubes are having near-perfect properties, all good for getting started.
What I don't like about tubes, in particular power tubes are the voltages in the kilovolt range near the knuckles while doing adjustments or heat that puts a sauna to the shame ...
@@ralfbaechle Working around tubes does teach you to be careful. And to keep one hand in your pocket.
@@ralfbaechle Yes, semiconductors take some teaching. But once you understand the theory about how a semiconductor works, it is no more difficult to learn about transistors than it is to learn about valves.
OMG I had this exact transmitter when i was a kid! We got it at a garage sale. I remember the seller saying "oh , oh thats trouble" picking on me for wanting it at 10 years old
WELL??? What happened? You got in to trouble, didn't you? :)
@@ricande nope lol we lived 40 acres in the middle of nowhere. But that transmitter worked great. Dont remember what ended up happening to it. Maybe still at my parents house
Believe me your mother threw that “junk” away when you were away in the ( fill in the blank).
Military
College
First out of town job
Your own entry here…
@@josephpadula2283 My Mom would neatly line up shiny solder balls but stuff nasty ol' green circuit boards in the trash . . .
I love your very clear explanation. I have refurbished that kind of stuff along with jukeboxes since the 80s, and I would have liked to have someone who explained things that clearly when I started to be interested in electronics.
Items such as what you presented here, can be found at Ham radios swap meets. I like to pick up such items as they probably do not work, and see if I can make them work. Some of my favorites are Heathkits of all kind, as these items where all built by someone, and the manuals for them can usually be found on the Internet. I like the simple kits, as they are fun and easy for me to trouble shoot and they maybe useful in my Ham radio. Thanks again for a great job of explaining how all of this "old stuff" works!
I made an AM transmitter for my grade 8 science project, the design was from Howard Sam's "Having fun with Transistors". It used 2 2n107 germanium transistors and I had to wind my own antenna coil. It had a range of 6 feet and appeared on 7 different points on the tuner dial.
7 points simultaneously? Lots of harmonics..
Back in the day, Stancor and Triad were the big dogs on the street for transformers and could easily run up to 1/2 the cost of the kits or more, so line voltage design, while "tasty", allowed a fairly affordable build for the hobbyist kid- like I was. My best friend and I would head to the dump about once a month and harvest components from old t.v.'s and radios we dug up for our reuse. Once we took a bucket of tubes to the local supermarket that had one of those courtesy tube testers there, but we were thrown out after about a half- hour of using their electricity and not buying any of their tubes. ☺
Damn, those were fun times for a coupla entrepreneurs!
Very entertaining always informative. Thanks Mr. Carlson
You're welcome Chris!
Wow - I went back to my own little example. Replaced C-7, the 470pf - I had no suitable mono caps, so I used a 470pf silver-mica. It's as stable as the transistor radio I'm using to 'preview' it.
It used to drift for about 20 minutes before it warmed up.
Thanks!
A relay, actuated by the effect of a magnetic field developed by the current in its energizing coil(s). There used to be 4 manufacturers who built this device, now there are still 3 offering it to the market. Originally, this device was used by the military (like many of those things). BTW, Paul, next time please hide the part number on the device. This one was easy to read and google offered the answer right away. :)
I've got some old Allied Electronics catalogs from the late 50s and early 60s I found in my cousins basement. Great stuff to look at and reminisce. My dad had a knight reel to reel tape recorder when he was a teen.
By the way, I believe every video you publish on youtube, Just like you, I am a serviceman technician here in our locality, I restore, repair, and even install electronic equipment as what my clients wants me to do.
I borrowed one of those from a friend's father. I am so guilty of taking parts from it. The FCC always has had over kill rules. The real technique here is a short antenna with a tuner and some ground plane. You need adjust your scope to get in into envelope mode. Then you can guess modulation percentages.
Your a very good teacher, thanks.
Wow - I remember every detail from age 9 when it was a brand new kit; I wish I had kept it.
( I built TWO of them! Worked, but I never could get the range to go beyond a few houses. RF was
a complete mystery to me as I experimented with various antenna "wires" and overworked that
slot on the tuning capacitor. Unsupervised 110 VAC construction by a kid... good old days! lol)
I have not built a tube type, but I did build a Crystal receiver with the old bare crystal and cat whisker and about 150 feet of antennae with my dad when I was about 9 and it worked! but I think we were smarter back then, kids now days they would have the "stick the wire in your butt and plug it in challenge" HAHAHA
@@kenseastrand7428 YES! I'm happy to hear that (back then) you found the exact sweet spot in that bare crystal. A "modern" germanium glass diode did not produce the same thrill for the next generation... And today, it's got a touch screen.
Another great learning experience, I had one of these Knight Kit broadcasters when I was much younger, really brought back some great memories!
Glad you enjoyed it
Thx Mr. Carlson ! Your explanations are both clear and concise and entertaining often ! I wish I had decided to become an instructor years ago as I think I would have followed your lead. My instructors were quite dry most of the time and thus quelled most of my original desire to learn electronics as originally intended. I look forward to following your coursework. The materials of CREI were my original material obtained and it was quite good. They were sold to another company and quickly went downhill , dang shame as many followed them at the time.
If that kit was available in the UK the chassis would have to be earthed (grounded), especially as it is a transformer-less circuit. Thinking about it, it would have a mains transformer to improve safety and use 6.3 volt heater (filament) valves (tubes). The UK and Europe have 240 volts mains, so dropping the filament voltage would be less easy.
I built a KnightKit Phono Oscillator in 1964 and actually Increased Output and made it Crystal Controlled, 1600 KC. I lived in Benton, AR. on a Large Lot, on River Street, and never got a complaint. It was a simple kit with excellent Schemetic and Pictoral Diagram. I was 14 Years old.
Oh did this bring back memories. I built one of these back around 56 or 57. Didn't work that great but it was a lot of fun...
Knight kit had some pretty cool products. When I was 5 years old my father built a C 27. It was a unique two channel CB. It had a VFO so you could listen to all the channels you didn't have. His callsign began with the number 5. The ITU put the kibosh on that so the FCC switch to the letter K as a prefix.
I built one in my youth (early 1960's) and used it to jam the local radio frequency of my sister's favorite radio station. What a blast.
April 28
Just
This was one of my first electronic projects at age 12. I read about the 12 inch antenna restriction, but it worked so much better attached to the families' steam heating system. We broadcast about 2 miles. Had so much fun. I never figured out why that even worked, because the steam pipes went into the cellar, and hooked to the boiler which had grounded water pipes.
Andy
I can remember one Christmas about 1950 when my older brothers had this device. They imitated the "HADACOL" adverstisment. The All american 5 were also called an AC/DC radios.
People in the rural area with no ac could but batteries to add up to 120 Volts and have a radio.
Always enjoy you bringing out an older piece of american electronics. Things we can definitely still learn from. Thanks Mr Carlson!
I had 2 of these when I was a a kid in the mid 60's. Drift was a major drift problem. I used the speaker transformer as input and plate modulation.
I could really see myself using this in my teens. I used a really crude Walkie talkie setup and for longer transmissions a mobile. This was when Mercury released a free 6pm-6am tariff.
Man I was wondering what the blue & black device was doing, displaying random numbers. Then I realised it was my phone's voltage.
My brother and I had something very similar to this back in the 70's. It was a 7 or 9watt AM broadcast amp. We would broadcast our radio station WAMAMFM through out our neighborhood. I'll never forget the fun we had. Sometimes my brother would walk up to Mr. Doughnuts at the end of our street to buy cigarettes from the vending machine there for 45¢ and he'd have his transistor radio with him to check our signal strength while I would broadcast. I'd broadcast what kind of doughnut I'd want him to bring home and would have to promise over the air to pay him back. It was sooo cool when he brought home the right flavor doughnut.
I never knew there were that many young guys like me that loved to “experiment” making our own broadcast stations. Later on I bought an FM kit and supposedly it had a limited range. I was able to pump out a signal for about a half mile or so. Didn’t have a PLL so the signal would drift. But it was fun.
Oh man, am I glad I watched this one! Very glad you pulled out the schematic and went over it with us. I've mentioned before that I have a guitar amplifier project I messed up in my youth. A decade or more later and it is time to finally get around to correcting it.
Excellent modulation for such a small device.
Lafayette Radio made these AM broadcasters also--and in fully built form. They continuously but slowly would drift off frequency--even after being on for 5 or 6 hours--requiring listeners to retune every 15 minutes or so. But for $5, the broadcasters still were a good deal and lots of fun.
An interesting video. I had not heard of this device. In my ham career I've played around with Knight Kit transmitters. AM radio, hmmm I may or may not have "accidentally" warped the tuning of my Viking Valiant's 160 Meter vfo into the top end of the broadcast band.
Ok, I'll be the gumby to say it. Mr Carlson looks like a very young version of the doc. This is really episode 4 where he's stuck in 2020 and misses his childhood transmitter. And, yes the radios RF output is 1.21GW.
You have a wealth of knowledge, can u tell us about your education, without getting too specific ??
That is the coolest Vacuum relay I have ever seen.
I wonder how many youths used those little home weather stations in combination with these Knight Kits to provide accurate extremely local current weather conditions.
Nice review of this transmitter. I saved one of these from the trash. It is the earliest model of Knight kit broadcaster that did not have a bottom cover. They must have felt that who ever built it would keep their fingers out of it. After a few years they did come out with the model you have.
Plenty of good ZAPs off top of chassis; twitches when touching parts underneath could damage set ! ! ! 😂
@@kendoty2463 More likely it teaches a healthy respect of AC. Try flipping the plug to reduce the tingle on the chassis.