1921 Spark Gap Transmitter / Ham Radio

This is an operating reproduction exhibit I built of a 1921 spark gap transmitter used by Amateur Radio operator John Westcott, W8AGA. It was built for a house museum where John once lived and operated his transmitter, but the museum reneged on its agreement with the radio club and the exhibit was never installed.

Category:

Howto & Style

Tags:

• spark
• gap
• ham
• amateur
• radio
• Morse
• transmitter

[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

[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.

[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.

[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)

[NorbertZF]

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

Thank you!!!

[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 :)

[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! :)

[wa1ufo]

Awesome!