1921 Spark Gap Transmitter / Ham Radio

[essoterric]

I love it. That's CQ with real soul.

[AdesMaz]

work of art thanks for sharing

[HamRadioReviews]

Awesome coil forms!

[emwavemhz]

What a great era in radio history! I find it interesting that ships at sea could hold QSO's out to as much as 1500 miles with spark transmitters and crystal diode receivers on long wave frequencies to be fantastic. I think we have missed a great time to have been radio operators. 73's

[teslacult]

The iteresting thing is that the impulse wave that a device like this transmits tavels so much better than modern transmition wave forms.

[jsmythib]

this is back when communications and welding were not unlike animals :)

[wa1ufo]

Awesome!

[zker666]

couldnt you possibly modernize this by bypassing the switch with a relay driven from a MOSFET driven from a digital circuit so you can program the calls?

[kb8wfh]

@zker666 Sure, I suppose you could. The key actually triggers a relay under the table to there is no direct linkage to the transformer current. So you could set up a digital circuit to turn the relay on and off as programmed

[wackyvorlon]

Looks almost like a tesla coil.

[Quadsly100]

Those Were the "Good O'le Days. I think .. Just "not" for The Titanic!!

[N5VAG]

Any schematics and measurements and things like that on building your own reproduction spark gap transmitter? I would like to build one just for historical purposes. It would also be fun to hear what they sounded like on the air on a special event if they have one since I missed the golden age of radio in the 1920s and 1930s by about 60 years hihi.

73 de N5VAG

[kb8wfh]

@N5VAG I do, but they are all packed away. When I go through them, I will see if I an scna them in and post them sometime.

[krimskrams]

@kb8wfh i think many people will be greatly obliged to you. i would love to have a showpiece like this! do please help us reconstruct these beauties! :)

[w5txrmark]

Very Nice!

You must be a craftsman too.

[AlienRelics]

I'd love to hear what it sounds like in a receiver. Wouldn't this be a "singing gap"? I think that is what it is called... essentially AM modulated CW, modulated by the rotating spark gap.

[zker666]

I would definitely use this for a tesla coil!

[romeo9k]

It's a little hard to hear, but isn't the call sign W8AGL? Maybe that last dot goes with something else, but it sounds like part of the last letter of the call sign. Anyway, those sparks look way cool. Ham radio back in the day.

[kb8wfh]

I had to splice some footage and the last letter did get a bit mutled. The call is W8AGA, that of John Westcott who operated the original SPT in a home designed by Frank Lloyd Wright here in Springfield.

[WA5MUF]

Very good!

[popeyeus]

was the antenna capacitor coupled to remove the high voltage and pass only the radio frequency modulation of the spark gap or was the antenna hot along with the key?

[popeyeus]

now was the antenna capacitor to remove the dc current and pass only rf or was it straight high voltage modulated at rf frequencies like lightning static crashes?

[kb8wfh]

The capacitor AND the coil were used as a tuned circuit, but also removed teh direct current. The antenna is not directly in contact with the spark/capacitor/out coil circuit.

[jc4def]

this is cool i plan on building one of these for my senior project :]

[dnl5649]

i now have my license and am operating a hf and 2 2 meter rigs

a total of 114 watts peak envelope power (pep)

[lbevIT]

Great video!

[lbevIT]

great

[gmcjetpilot]

Question to any one, these transmitted on a very wide band width, basically a blast of RF that splattered across a wide spectrum of frequencies. It was just a spark impulse. Thanks

[KC0TCH]

if you get a chance, go see the titanic museum in branson mo. they have a straight key hooked up to a spark gap generator there for people to try out.

[Penfold8]

Well that's one way to straighten your hair!

[toobroke2fight]

whoever put all that time and effort into building that is a wonderful craftsman! It is a wonderful example! WOW im speechless! BEAUTY!

[kb8wfh]

Absolutely!

[bloggycreek]

That is a hauntingly beautiful sound.

[sonick808]

Truly a thing of beauty. Great job.

[Rippey574]

I am attempting to do an spark gap transmitter. what i am trying to do is actually output modulated sound like with a modern unit (am C.B. {U.S.A.} style) with the spark gap. Is this possible or is spark gap limited to CW operation only?

[kb8wfh]

I have a vague recollection of hearing about some early experiments using a rotary gap to modulate a phone signal, but I don't think they were at all practical or usable. However, it was ultimately unnecessary as AM signals were possible with carrier signals with newly emerging vacuum tubes. I really wouldn't bother to try it with a rotary gap to generate a signal. I doubt whatever you got would really be intelligible.

[NorbertZF]

Excellent! Wish I had one. I also have an interest in the wireless transmission of energy as per Tesla.

Thank you!!!

[boxa888]

hey norbert i put up information on teslas wireless energy transfer through the earth if you are interested!

[Izgiftd1]

not Norbert but I wouldn't mind any info you could send on HAM radios, Im just seeing the usefullness of it and could use whatever info you have

[WA5MUF]

I bet not too many RSTs with a T of 9 were received back in the Spark Gap days! Great video -- thanks a million.

73,

WA5MUF (Same call sign since 1965)

[trisoctehedron]

I am sure glad I got to see a spark transmitter at last after reading about them for so long. I've never understood why they need a rotary gap. Looks like you could just key a stationary gap with high voltage applied to it and get a spark. If you feel like explaining I will be very grateful.

[dnl5649]

They have rotary spark gaps because a stationary gap would melt itself and a rotary gas make a better tone on the radio reciever.

I am 12 by the way and I have 3 spark transmitters I made.

[rockymountainradio]

you can do, but whith higher powered machines the nead for spark quenching became greater, and thus the rotary gap came in, as can be seen in the video, it stretches as the disk roates causing it to cool down faster. they were used with AC and produced a more regular and much higher powerd spark. hope this helps

[kuernodechivo]

I think I heard someone running voice into one of those on 27.025 (The Bowl)

[RckyMtneer]

Thanks for posting that. One of my grandfathers, u6CCY, had one of those in the 1920's. I still have his original licenses that state he was authorized to run spark gap. Kewl! Rick N0VLF Colorado

[Mindraker1]

Good heavens, mate. You can hear that thing humming.

[Organgrinder010]

Beauty. You do fine work.

[gedanate]

Wow! So now I really understand why early ships' radio operators were all called "Sparks". Thank you very much. I've got to show this video to my XYL, but she already believes all Hams are crazy. :-)

73 de David, vk2dmh

[greenmountainsolar]

narrower signals than the flex radio i heard tonight on 75?

chris/N3GAD

[tonijn1969]

long wave???

[jeffpicks]

Masterful piece of work OM!

Build some more ! (or if you already have, let's see !)

Guys, THIS is what ham radio is all about...

not that drivel you hear on 75 mtrs... or your local repeaters.

[SpeakUpNow]

Isn't that slightly illegal to fire up? Imagine every cop/fireman in the city heard it on all bands?

[kb8wfh]

Nope, not a problem. Its made to "look" and audible "sound" like a transmitter, but it actually doesn't generate a signal. None of the tuning circuits are hooked up and everything metal is grounded.

[w4csc]

No wonder it doesn't get out far! Look at the coils....The coupling's too tight and killin' the circuit...(c;

73 DE W4CSC

Charleston, SC

[kb8wfh]

Just the way I want it! ;)

[ballores]

great vid makes my fillings tingle just to watch it!

[CT4RK]

Fantastic! I love it!

best 73 CT4RK

Carlos

Portugal

[KC0TCH]

"W8AGL?" why is there a question mark at the end of the call?

[kb8wfh]

The actual call it is sending is W8AGA but the video is spliced with another section of video/audio asking QRL? making it a little hard to hear the intended characters sent.

[KC0TCH]

oh, i see i guess that happens sometimes.

[KC0TCH]

If you get a chance to visit Branson MO, drop by the Titanic Museum. The radio room display has the equipment from the Olympic, Titanics sister ship. There is even a key and spark gap that museum visitors can interact with. The tension is too stiff for me though.

[MorticiaMaquette]

Very nice work. Thanks for sharing it. It would be nice if there was some sort of voice-over describing the various parts.

[albear972]

Awesome! "*****" I didn't know those old transmitters used electric motors? wild thing to see working!

[Kernow97]

Nice video,

es 73

Regards,

Drew

[Postie1]

That is totally wild. I had never seen a spark gap transmitter work before. Thanks, great job.

[NorbertZF]

That IS museum quality! You did an XLNT job making this. Thanks for the video.

[bugsier5]

.-.. --.. .-.. --.. .--. .... .-.. .-. -.-!!

[kb8wfh]

L  Z L Z P H L R K?

QRZ?

[TheMaestro2]

That's awesome :p, though don't the ozone levels get a bit high? :D O well cool thingymajig :p

[timewind76]

Vry FB es gud ozone. K9VA

[CassetteMaster]

AWESOME!!

[patchcords]

Wow that's great!

-VE3RKP Chris

[falcon3d]

Thanks for sharing your spark gap transmitter...those must have been exciting days listening to the spark rigs...wow...long live CW...Ralph WA6STC

[py2fwa]

Fantastic.

[ct92404]

That's awesome! I've heard of spark gap transmitters, but I've never seen one. The voltage looks to be pretty high...much higher than I thought it would be! I'm just curious - how high is the voltage, and what kind of transformer does it use?

[Sparrow338]

Judging by the size of the box the transformer seems to be housed in I would guess that it is a NST or neon sign transformer. I would think it would be around 9-12kv @ 30 ma, just guessing though, i don't really know.

[kb8wfh]

It is a modified neon transformer at 15 kv output. What you see as the transformer box does house the transformer, but the leads coming off of it are not the actual lines.

[kb8wfh]

I designed and built it to be used safely in a public museum environment. The transformer extends below that box into a cabinet. The actual lines that run off the transformer run under the surface of the case into to the rotary gaps from underneath. The lines you see on the surface of the exhibit are actually grounded for safety.

[dermengi]

very nice transceiver....hi hi hi...73s best dx from yo3br edy bucharest romania

[fryloc359]

I just realized I know even less about spark gap than I thought I did. Nice work.

[SatoriSoul]

Very well done.

[6aabattery]

After seeing references to Spark Gap radio, now I have fairly decent idea of what it is. Like the fit and finish of the wood work, good job!

[keithpaw]

Fantastic! M0 PAW

[urogallo2]

Excelent demostration, please add audio comments to the equipment.

73

[kg6ejp]

Absolutely awesome!

[youcoto]

very pretty your tranceptor you felicito.73 warm of CE3WIT Santiago of Chile

[u1969]

W8AGL we read you loud and clear. I would have enjoyed an audio description of the equipment such as the wattage output or where this transmitter came from. It's still an original video worth viewing.

[kb8wfh]

The transmitter came from my wood shop, my ham radio test bench, and past collected over a 5 year period. When I get some time, I will try and compile a list of what it is you are seeing in the video. Thanks for the comments :) 73