Topband: 1000 feet 5/8" hardline or 600ohm True Ladder line.

[Jim Brown]

On 4/29/2014 2:59 PM, Mike Waters wrote:
> His graph showed almost identical, overlapping loss curves for "RG-6/U" and
> "RG-213/U" from 1 MHz to almost 100 MHz. I'm 99% sure that Owen's RG-6 had
> a solid copper center conductor, and it was something he obtained there in
> Australia. I don't know what the shield material was.
>
> Here's what Owen said:
>
> "The graphs are total loss... so copper loss is in both conductors, but if
> you examine the geometry of most coax cables, most of the loss is in the
> centre conductor (typically around 70-85%).

For the cables Owen is talking about, his analysis is in the ballpark. 
Those cables have dense, uniform copper braid shields. But most RG59 and 
RG6 cables are made for CATV and MATV, and those cables have Al foil and 
thin braids, so the loss in the shield is MUCH greater, especially in 
the low MHz range. He's also correct that a CCS center is thick enough 
for VHF, but not for 2 MHz.

He is also correct that all the loss is due to copper -- indeed, all the 
loss is due to copper until you approach the GHz range unless there's 
something wrong with the dielectric (like water or contamination from UV 
acting on the jacket).

Repeating my original statement -- RG-numbers do NOT adequately describe 
coax cables. You MUST look at the manufacturer's data sheet for their 
part number to know how it will perform.

73, Jim K9YC