Subject: Avoiding attenuation in radio waves with vaccuum tube?

This is just a thought experiment.

Suppose I could make a perfectly straight tube 100 km long.

I then created a vaccum in he tube by removing all sir from the tube.


Into that tube with a directed antenna I inject a wifi radio signal.


Is it possible that the signal would reach the end of the 100 km 
vaccumed tube unattentauted - except for maybe munus 5%.

I am asuming that the tube is heavily insulated on the outside with a 
"dielectric and is made of a metal like copper on the inside.

The idea is can a vaccuum overcome attentaution of radio signals.

Re: Avoiding attenuation in radio waves with vaccuum tube?