# Ground radials: Electrical difference between 14 gauge and 18 gauge? Lifespan difference?

I am starting the process of installing a vertical ant (6BTV) and radial ground system. I am ready to buy the wire.

I would like to know if there is an electrical difference between 14 gauge and 18 gauge wire when used as a radial ground system?

I would also like to know how long the 18g will last compared to the 14g?

For instance, can the 18g wire be reasonable expected to last ten to fifteen, or even twenty, years while laying on the dirt with grass growing over it?

How long might 14g wire be expected to last?

• Thank you both for your thoughtful answers. They were very helpful. After a bit of research, it appears that 18g insulated wire is more expensive than 14g insulated wire. I bought 4 rolls of 500' 14g stranded wire from a local home store and am in the process of cutting the radials to 66'. Perhaps you'll hear me on the in the near future. 73 – MarqTwine Oct 15 '18 at 16:28

Larger wire will have less resistance. However, the resistance of the radials in either case is negligible compared to the soil resistance, so I wouldn't worry about it.

Longevity would be my concern. Commercial broadcast towers use 10 gauge bare wire. Anecdotally, there are plenty of amateurs happily using 18 gauge wire.

Corrosion depends on many factors. Corrosion rates could be anywhere from 0.0002 to 0.15 mm/year, depending on soil conditions. Solid wire will last longer than stranded, due to decreased exposed surface area.

18 gauge wire has a radius of 0.51mm. Most soils won't be especially aggressive. At a rate of 0.0002 mm per year, it takes approximately 2500 years to corrode all the way through. So assuming favorable soil conditions, you'll be dead long before the wire rots away.

I think the bigger concern is mechanical strength. Digging animals can chew through wire or push it up. Frost heave and thermal expansion/contraction can cause the wire to pop up where it's subject to snags by foot traffic or mowers. Digging to plant a tree, etc. could cut a wire with a shovel. I'd expect to lose more radials this way than by corrosion. In my freezing, mole-infested location I bury the radials to anchor them more securely.

For the amateur, repairs are cheap and easy. So economically it makes little sense to spend a lot of money on robust wire. If 18 gauge wire hits the price point you need to install enough radials to have an efficient antenna, I'd say go for it.