I recently purchased a 500-foot roll of military surplus 14 AWG stranded copper wire at a hamfest for next to nothing . It is Prestolite M13486/1-6 (spec sheet).
It has very thick chlorinated polyethylene (CPE) insulation. The outside diameter is nearly 1/4 inch (.235 to be exact). My plan is to use it to lay out radials for a ground mounted vertical, and my assumption is that it should work just fine.
However, my knowledge does not extend very far into dielectric constants (actually, my knowledge pretty much ends right after looking-up what the dielectric constant of chlorinated polyethylene is: 5.5 at 1kHz).
In the past, as many do, I have used 14 AWG stranded copper THHN for radials in ground mounted verticals with good results. As far as the copper conductors are concerned, THHN is identical to the Prestolite. Both are comprised of 19 strands of 29 AWG wire.
The difference between the two products comes down to the insulation/jacketing:
- Prestolite uses CPE that is 57 mils thick. CPE has a dielectric constant of 5.5
- THHN uses PVC that is 4 mils thick. PVC has a dielectric constant of 4.0
So, there are obviously significant differences between the two in terms of insulation/jacketing and by definition, they will perform differently. My question is: Will these differences result in any practical, discernable difference in performance?