Tesla coil antenna? Answered
With the cold and bad weather out there I started again to tinker with my old UHF radio.
Trying to build a nice antenna to put on the roof of the hous and such things...
While looking up on the various antenna designs I could not help it and followed a few links with antenna designs and specs for all sorts of frequencies.
There are things like horizontal or vertical transmission waves or even circular ones.
But also some of the basics can be quite different, like whip antennas, dipoles or coiled ones.
The later we often see in these keyfob transmitters and receivers for door bells and similar low range, low cost options.
Some really old ham radio links got me to the topic or electrically shortening and lenghtening antennas.
Things like coils in a whip or added capacitors to match the antenna to frequency and transmitter.
A tesla coil usually produces a lot of RF interference, not just on the main frequency it operates on.
And from research and physics we learned that for really great distances you need really low frequencies.
Like for example the very low bands used for submarine communication around the globe.
Here antennas on land can be several km long...
The inventor had a few ideas in terms of wireless electricity and communication but I wonder if there is more to it...
Despite the broadband EMF a tesla coil produces it is also a really narrow beam antenna.
Basically the radiation cone is orientated straight up instead of the usual horizontal patterns we use for communication.
The topload again provides a spherical radiation pattern.
I am wondering about how a tesla coil would operate as a directional antenna if the topload is replaced with a whip style antenna of a lenght that matches the wavelength...
The hip would again provide a more or less spherical beam but the coil underneath would "puch" a directional from underneath.
In the classic design the topload is meant to prevent arcing while providing a capacitor so the whole thing is resonant.
At lower power arcing is no problem anyways, but what effect in terms of capacitance would a whip style antenna have?
Classic pherical or donut style toploads provide little to no gain in terms of antenna properties.
If you would use a sphere as an antenna for your CB radio then it would be perfect for very short distance but utterly useless for open range communication.
We all know the fun of placing a flourescent light near a tesla coil to show "wireless electricity".
Sadly this is more an effect caused by the high frequencies be able to produce the glow in the gas filling.
Trying to make an incandescent lighbulb glow is far trickier.
Several experiments show that two properly tuned tesla coils can work as transmitter and receiver.
But to my knowledge no one ever tried this type of experiment with an antenna on the tesla coil...