Co-ax V 300 ohm flat twin.

[Synchrodyne]

The attached article from Electronics World 1970 January gives a picture of the American situation at the time.  Clearly, by then 75-ohm coaxial was very much an established alternative to 300-ohm twin.


  EW 197001 TV & FM Leads-In.pdf (Size: 2.12 MB / Downloads: 3)

This advertisement from 1966 I think represents an early incursion of 75-ohm coaxial into what was then still a 300-ohm twin domain.

   

But screened 300-ohm twin was also a contender, one that in the event was pushed aside by 75-ohm coaxial.

   


Cheers,

Steve