Very nice legacy build! It’s attractive too! Amazing how little chirp it has. So your secret was to use an 837 and not an 807. Listening to it on the air you wouldn’t know it is a one tube transmitter. You did a marvelous job putting int the light bulbs as power out coupling indicators and explaining why meters weren’t used then. This is exact what a depression era CW transmitter would look like. Vacuum tubes were expensive after all and money was tight. Likewise a ham would buil a one tube regenerative receiver and rely on high impedance headphones which were in plentiful supply back then. They would also operate split frequency because crystals were expensive and hams would tune around listening for a response to their CQ.
Great construction and demo. At 77 y.o. you've brought a lot of memories of the past when, I also used to build valve transmitters for fun. I progressed from a single oscillator valve - like yours - to full three (oscillator, buffer, output) valves, using 2 x 6146 valves with 700 v on their plates. These used to be days of 'fun', with immense levels of satisfaction in the knowledge of operating a self constructed transmitter. Now, in the Solid State era and Class D stuff, things are different...perhaps more efficient but...less fun! Thanks for the great video and 73's from 'Down Under'. 😀
Remarkable how hams were able to build their own rigs back in the glory days of radio. My great grandfather built the first operational church radio station in the US back in the 1920s. He also built his own rig and used it to talk to countries as far away as Europe to the east and Australia to the west. He even gave his daughter's fiance in New Zealand permission to marry his daughter over his radio from his home in New York. This was in 1926. Couldn't have been much more than 25 watts.
You might be right about the 25 watts... that was power output but the power input required on a 1920s transmitter would have been near a Kilo in those times. Hardly anybody had tubes then, even though the military had them developed about 15 years before that. The old spark transmitters had an horrible power input to signal ratio.
How is there not more subs. RU-vid is hurting your channel. I can't believe this is the first time I've come across it. Glad I did finally find your channel. 👍
A very enjoyable project Justin and great to get the feeling the experimenters back in the 1930s would have had putting the breadboard transmitter together. I've previously built a single valve transmitter using an EL84 or PL84 with switched heater supply on a wooden cigar box which was fun. Planning to build a solid state modulator and get it all into a metal project box for safety in the near future. Great video.
Love this! Been learning Morse since mid 90s, intermittently. I'm at the stage now that I can receive all the alphabet. My 90s Morse tutor Mary, London, explained there's no point in learning it if there's nobody to converse with. It's a shame our local HERC seem to be so reluctant in training me, from being a 2E1 to a G5xx. I'm the only 1 willing candidate during a surplus gear auction to express a desire, but that wasn't enough. Sad. What a fascinating hobby! Thanks 73. 2E1FQN
I'm a tube amp junky that made the natural transition into radio world...I'm playing around with my parts stash experimenting. I bought ta quasi-legal UV-5R to fill the gap and for emergency,, very much like your delema...no one to listen too as I'm currently unlicenced the airwaves are dead! I added an rf amp in hopes of extending range, still no dice!. At this point I'm about to give up thinking that this is a dead end hobby, which sucks because this s#it is really neat! my question does one not need to know morse in order to get licenced?
@@624radicalham not been at it continuously. I've mostly been making up songs and other things like battery valve guitar amps. I only has a spasmodic interest in Morse. Spasmodic pretty much sums me up: a bit of a spaz! Yay! Thanks for comment, n fing. 🎸👀🍄🙂
Just found you. I must say, the sound is incredibly stable. Nice build of a 1930's transmitter. I'm now going to check out your other videos. Thank you for sharing. Jim
Hi...mister.... i like so much about your 2 stages tube transmitter.... especially your skill to make communication with cw.... last time i did with am 3,7 MHz.... The last i used 5 stages.....813 x 2.......450 Watts.... only for speaks and songs while speaking likes broadcast... i am from Jakarta...Indonesian...
Прекрасно!), неповерите, я как раз обитаю в литературе 20-30х и раньше, в эре искры идуги, да интеречные были времена, но у нас на постсоветском пространстве непопулярны такие вещи почемуто😢, успехов Вам, и 73. UZ7QAO
Nice 30's breadboard rig, Justin! I have built a replica of the Norwegian agent set "Olga", which uses one 6L6G with xtal control. I also have one British Mark XV TX with a 6V6 and a 6L6 in the PA (SIS, Whaddon). Like yourself I prefer using more modern receivers. Maybe we could meet on 80? I have a number of xtals on 80, 3560 is ome of them. Beat of luck and 73 de Stein, LA9QV
I have 1946 ARRL hand book showing a 25 watt master oscillating crystal controlled 807 and using plugin coil with the HT passing through it. I think that a 6L6 is the same as a 807 from what I have read. You mentioned 12 volts and the valve you are using must be the 12 volt version of the 807 which is a 1625.
I have the 1961 38th edition, I'm not a ham radio operator but I do build custom guitar amps and repair vintage gear and yes the 807 is very similar to a 6l6 in fact you can buy adaptors to run 807 as 6l6s and vise versa allegedly. I have a hallicrafters s-20r and I love it.
Looks like an 807 tube. (As vid was starting. Turns out it’s an *837.* (Do you keep the tube in the Fridge when it’s not under power? Joke, e.g. “Cold 807.”) Note: 837s are a fair bit cheaper than the look-alike 807, are true *Pentodes,* and look likely for possible experiments.
My first electric shock was off the top cap of a pair of 807s in a audio amplifiers. I can still here the music in my head now some 50 years ago. I'm amazed I lived to tell the tail. Funny, not used the 807 ever since, in fact no valves with a top cam.
In order to produce intelligible telegraphy a proper electronic keyer and not an old Vibroplex bug should be used. This sounds ugly, putting it mildly!
