does anyone use the double core coax ?

[Catbrain]

Is the kind that has two center conductors and a braid around both--- is this used in ham radio ?
im thinking it may not be because i would think it would be just as lossy ( for longer runs) as the single core coax......
and maybe its only advantage would be that it is balanced.

and-- ps --- how do you keep a long ladder line from becoming a squirrel expressway at rush hour ?
Does a twist every couple or 3 feet help that problem too ?

 

[mmckenna]

Twinax. A very long time ago we used that at work but it was for a very specific kind of data network. Not to be confused with twisted pair cable that has individually shielded pairs.

Never personally seen it used in radio, but I'm sure someone has, especially if a ham found it inexpensively at a ham fest.

 

[rf_patriot200]

Is the kind that has two center conductors and a braid around both--- is this used in ham radio ?
im thinking it may not be because i would think it would be just as lossy ( for longer runs) as the single core coax......
and maybe its only advantage would be that it is balanced.

and-- ps --- how do you keep a long ladder line from becoming a squirrel expressway at rush hour ?
Does a twist every couple or 3 feet help that problem too ?

Ladder line has spreader bars that keep equal distances between the conductors.

 

[Catbrain]

I was just imagining that since it looks like a ladder---- mr. squirrel will use it as one prob.

 

[WA8ZTZ]

Twinax cable was used with the IBM System 34 terminals (5520 or 5250 or something like that, IIRC).
Impedance was 100 ohms, again IIRC... this was a long time ago.
One conductor was tinned copper and the other was bare copper.
The connectors were a bit tedious to install as they were soldered on...
quite a task on a large network with a bunch of terminals and printers.
As far as an application for a ham radio antenna... IDK.

 

[merlin]

Some old military radios used Twinax because it is balanced. I think it just vanished in the early 70s because it is expensive to make.
High speed data, maybe T1, but that is all CAT5 and 6 now.