Spark Gap Transmitter, Car Ignition Coil & Simulated Rotary Gap Sound, Part3

[@ktheis1]

Outstanding! Exactly what I was thinking about.

[@joesmith-je3tq]

Good to hear.

[@wktodd]

On my next trip to the wilderness I'll be sure to pack a joe smith just in case 🙂

[@joesmith-je3tq]

As long as you don't plan to travel more than a few feet into the wilderness, you should be fine. lol.

[@wktodd]

@@joesmith-je3tq That's ok , there are only a few feet of wilderness around here (mostly between the backdoor and my shed 😀

[@SteveAB4EL]

It's not loud enough! My father told me that the local prep school (in the 1920s) had a spark gap transmitter in the gymnasium building. When they keyed it, *"you could hear it from across the street."*

[@joesmith-je3tq]

I can believe that. But because my goal wasn't to radiate enough to communicate much further than a few feet, there's no need for a lot of big arcs. After all, part 1&2 was using a couple of AAAs and a fly swatter for a source. lol.

[@reedreamer9518]

Playing with high voltage is fun. I built a Jacob's ladder once and was having lots of fun, but it produced so much ozone I felt ill and had to open the door and windows to let fresh air in. ; )

[@joesmith-je3tq]

I'm pretty sure my laser printer puts off far more ozone than these experiments. If I print a few sheets, I can smell it. I haven't detected any odors working with the transmitter.

[@AlexBurtonMusic]

In an old book I don't remember the name of, I read that the quenched spark gap and the rotary gap can be connected in series to improve the tone. I'm worried that this might disrupt the function of the quenched gap. How likely is that, sir?

[@joesmith-je3tq]

Tone wise, you would need to use AM demodulation or a BFO. With what I have shown, the BFO will not work with the pulsed, decaying signal. So we are stuck with AM to get some sort of tone. A while back someone posted a comment about Poulsen's oscillator. Because now we are now looking at a CW signal, we could possibly use a BFO. This may work but anything I have read, they never achieved frequencies above a few hundred kHz. I don't see why a rotary spark gap could not act as a quenched gap. After all you are just trying to extinguish the arc faster which means opening up the gap (or some other means).

[@AlexBurtonMusic]

@@joesmith-je3tq Max Wien's quenched gap is superior to the rotary gay discharger, according to what I read. When they were still in use, most amateurs didn't have a generator in their homes to determine the discharge tone and rotate at a certain speed, so the quenched gap gave a very poor tone with 60 Hz AC taken from the outlet, which ultimately gave a 120 Hz tone. When it was powered by a generator, every time the morse key was pressed, the generator was put under load, and because the speed of the generator slowed down, they got a chirping, unsteady tone. I wondered if we could use a rotary discharger to adjust the tone and at the same time get the benefits of the quenched gap, when they are connected in series with each other.

[@joesmith-je3tq]

@@AlexBurtonMusic If you watched this video, you could see I cycled this setup much faster than 120Hz. If you check out the following link, shown is another transmitter for the 10meter band cycling at over 4kHz using the fly swatter. www.eevblog.com/forum/rf-microwave/fly-swatter-ham-radio-transmitter/msg5242794/#msg5242794

[@joesmith-je3tq]

I have updated that post to include data running at 9.4kHz and calculations for the required RPM for an eight gap rotary. Feel free to join up and post any comments there.

[@gamesgonenuts]

this was so interesting to watch smashing the like