View Single Post
Old 29th Nov 2018, 12:01 am   #14
Argus25
No Longer a Member
 
Join Date: Oct 2016
Location: Maroochydore, Queensland, Australia.
Posts: 2,679
Default Re: Coax cable - When did it begin?

I have seen some interesting variations of coaxial cable in pre -WW2 TV sets in the video sections. Also a very similar type of cable used in Tek EHT probes and some 400MHz scope probes. The idea is that a single very thin conductor sits loosely inside an insulating tube/sleeve with an air gap and it only touches the inner surface in occasional places. The thin central conductor has a very small surface area reducing the capacitance. Because it is very thin, it is often made of Nichrome to get the strength. But this kind of cable is easily damaged by careless handling.This also makes it awkward to solder and it needs crimping. It is a way to make very low capacitance per meter coax.

There are plenty of short braid screened wire link setups in 1920's radios especially in the audio sections, but I don't know if it would qualify as "coaxial cable" which would be designed as an RF transmission line with some characteristic impedance and termination for longer distance signal distribution.
Argus25 is offline