[TowerTalk] Fwd: Old Hardline

[Steve Maki]

For a given cable size, impedance, and conductor material - one can 
compare center conductor diameters to find the cable with lowest loss. 
The one with the airiest dielectric will have the largest center 
conductor and the lowest loss.

-Steve K8LX

On 11/14/19 21:26 PM, jimlux wrote:

> On 11/14/19 6:08 PM, Robert Harmon wrote:
>> Interesting stuff.  I got on the Trilogy website, they have a 
>> corrugated copper outer conductor too.  Can't
>> find loss specs for lower HF freqs.  Also suppliers and cost.
> 
> For HF, the loss is dominated by the skin effect in the shield and 
> center conductor - especially for hardline, which has almost no 
> dielectric.  So the loss will go as sqrt(f).   If the loss is, say, 
> 10dB/ft at 10 MHz it will be 3.2 dB/ft at 1 MHz.
> 
> More details here:
> https://www.microwaves101.com/encyclopedias/coax-loss-calculations