Plasma wire -- turning an antenna on and off very quickly

[arydberg]

Someone asked if it was possible to conduct electricity through a wire with a plasma. I ran across a article about a inventor who wanted to turn a antenna on and off very quickly. He said it was possible to do this by using a florescent light bulb as a element in the antenna. When a high voltage was applied to the tube it became conductive but when the high voltage was turned off it became non conductive.

 

[jerromyjon]

Sounds accurate, that's what happens with lightning in the atmosphere, when the trails are forming they cause plasma channels which conduct the main discharge.

I ran across a article about a inventor who wanted to turn a antenna on and off very quickly.

If you want more information you would have to supply a link or a specific reference...

 

[Baluncore]

The transmit/receive switches in early radar sets were based on small gas discharge tubes that conducted during transmit. The impedance mismatch created by the gas discharge in the line to the receiver reflected energy and so protected the sensitive receiver mixer diodes from the transmit energy. Those TR switches could switch on and off at 10kHz.
https://en.wikipedia.org/wiki/Duplexer#Transmit-receive_switch

 

[tech99]

Someone asked if it was possible to conduct electricity through a wire with a plasma. I ran across a article about a inventor who wanted to turn a antenna on and off very quickly. He said it was possible to do this by using a florescent light bulb as a element in the antenna. When a high voltage was applied to the tube it became conductive but when the high voltage was turned off it became non conductive.

This idea has a number of limitations.
1) The tube can only operate at a few kHz, whereas transmitters can often be pulsed much faster than this - so why do it?
2) The RF power itself would fire the tube at power levels above a few tens of watts.
3) If used for receiving, the tube will introduce a very high noise level. In fact these tubes are used as noise sources.