Kevlar Antenna Wire - Revised Perspective.

A couple of years ago, I wrote about the benefits of Kevlar-cored wire for antennas.

I concluded at the time that the relatively high price of Kevlar was worth it, principally due to it being three times lighter per unit length than Flexweave.

It won't be too long before I have to replace my 20m delta loop wire again.  Despite the Kevlar core, the braid of tinned copper that is wrapped around it eventually suffers metal fatigue, and an open circuit develops.

Kevlar-cored wire's strength is in tension, not lateral flexing.  Millions of movements over the years due to wind for a vertical delta made of this wire leads to the aforementioned metal fatigue.  So, I find that Kevlar cored wire is best used in situations like dipoles, end-feds, verticals, and so on.

Having recently re-wired the house with DC from a solar installation, I came to thinking that, seeing as Flexweave may well actually outlast Kevlar-cored wire in that it is less prone to fatigue (as suggested by my 17m delta, which is made of Flexweave), I ought to use some of the DC wire (which is the same as medium speaker wire), which is also, of course PVC coated.

Sticking two identical lengths of Kevlar-cored and DC wire on a kitchen balance, I was surprised to find the DC wire was a full gram lighter than the Kevlar wire.  If you multiply this up to the full wave length of a 20m vertical delta loop, that's a saving of 56 grams on the support.  That's much the same weight as two AA batteries - quite significant.  The width of both wires is the same, so there is no change in the wind-catching area.

There is also a big benefit to ditching Kevlar, because it's a pain to solder and add lengths to.  You need to remove the Kevlar fibres, otherwise they absorb heat and contaminate the joint.  This is important for repairs in windy winter weather.  You are also compelled to use spade or similar connectors, because the copper braid of Kevlar-cored wire has no strength at all.  With DC wire, soldering is simple, clean and strong.

Price-wise, Kevlar wire in its standard diameter is selling (mid-2016) for 90p per metre on a 100m drum.  The DC wire is selling for 52p per metre, handily in 25m lengths (for a 14MHz antenna), almost half the price!

Once again, I'm happy to be saving you money, without any loss in electrical or mechanical performance.