Wire Antenna material

[davenlr]

Putting up a 40M antenna to start with. Is there any reason not to use PVC covered 14 gauge stranded copper wire, as far as the signal is concerned (not worried about stretching at this point). They sell 500' rolls of it at Home Depot for $41, which would be much faster and cheaper than sending off to a ham radio store for their "copperclad antenna wire".

Just cuious, as most wire antennas are bare wire. Wondered what the negative effects of using PVC covered wire. Would seem it would be good to keep UV and rain off the wire.

Im guessing it will change the velocity factor, leading to a slightly shorter than 1/2 wave dipole electrically, but what effects would that have on transmissions?

 

[LtDoc]

At HF the size of wire makes very little difference. It really doesn't matter if it's insulated or not. Using insulated wire means the resulting lengths are going to be very slightly shorter than a bare wire. Since you will have to trim/tune the thing anyway, that 'extra' wire typically makes no difference. Pick a nice color!
- 'Doc

 

[N1BHH]

I've used minimum of 18 gauge wire to some decent effect. If you want an antenna to last in windy, snowy, rainy weather, that 14 gauge will do well. My current OCFD is made of 16 and has survive 3 winters, but will soon come down for a rebuild with 12 gauge. I use nothing but jacketed wire. At HF velocity factor doesn't mean much unless you are talking about a phasing lines for coax. The difference is so very minor, don't even think about it.

 

[n5ims]

Stretching is somewhat of an issue, but nothing major in most installations. If your SWR increases, you may need to retune the antenna, but that's about it. One thing that may (or may not, depending on your specific installation) is that standard copper wire (insulated or not) isn't all that strong and may break if stressed (due to the wind flexing the wire over time or perhaps if a limb lands on the wire). The copper clad wire not only won't stretch nearly as much as pure copper wire, it's also quite a bit stronger so there's less of a chance of it breaking. If your wire antenna is near tree branches (or especially if it goes through a tree canopy), the copper clad wire will pay for itself quickly by needing fewer repairs.

 

[LtDoc]

This is redundant, just saying things a different way.
There are two aspects when you look at antennas. One is electrical the other is mechanical. They do affect each other but in general are not the same thingys at all. If the electrical characteristics aren't at least close to being 'right' then it's not going to work all that well, right? And if the mechanical characteristics aren't close to 'right' then the thing isn't going to stay in the air (or where ever) very long. A little 'over-doing it' typically doesn't hurt, wire/tubing size for instance. You can go too far with that, and that's not a very good idea after some mysterious point. Where do you quit? When it get's impractical, and that can be different for everyone.
What's the 'best' wire to use for an antenna? Whatever you have the most of that can carry it's own weight plus some more. You can mix wire sizes without much electrical changes, it's done fairly often.
Have fun...
- 'Doc

 

[jackj]

Doc and n5ims have given you some good advice and the only thing I can add is that wire with insulation is going to be heaver than bare wire. It will also have a slightly larger diameter which will make a difference if you have ice buildup on it.

My advice is to use copper-clad wire. Why do the same job more than once?

Jack
N8BSR