Wire Stretch....

[WX2MIG]

This kinds goes hand in hand with the other post concerning wire types used for dipole antennas.....

When I got my TS-130S back in early February the first antenna I hung was my 20 meter dipole. In March I pulled it down and re-built it with heavier wire and a better built center insulator / coax connector. I used #10 gauge twisted cooper wire scrapped from heavy duty extension cord.

Over the last two days we've had severe thunder storms blow through with strong gusting wind bursts, and driving horizontal rain, don't know if that was the cause, or the icing on the cake, but I went to check into the Maritime Mobile Service Net this morning, and my SWR's were going crazy. I re-tuned, and tried again, and again my SWR's went crazy......

I dropped the dipole and measured the legs to discover they both stretched a foot and a half longer than when I put it up......

I re-cut, and re-soldered the ends back to the prescribed length for a 20 meter inverted "V", pulled it back up, and everything is back to normal. Got checked into the net, and received a 5X5 signal report from net control in 9 land.......

I had no idea this wire could stretch that much, but it did. Now I'm wondering about my 40 meter dipole, I used solid cooper electrical wire on that one. I guess one of these days I'll have to drop that one and re-measure to see if it has in fact stretched beyond resonance.......

 

[Beetle]

That's why so many of us OFs use Copperweld wire for just about everything. Next best, and a lot more expensive, would be solid hard-drawn copper. It's essentially prestretched.

If you happen to live around where motor rewind shops exist, you might try there for spool ends and such. I got such a good deal on #12 hard-drawn with Formvar insulation (2500 feet of it!) several years ago I just couldn't resist. Still got a bunch left, and I know where there's more.

 

[Robb]

It's great to be able to make antennas out of scrap wire - and copper in particular.

But if I was to build one from scratch in a VERY windy area - I think it would be time to switch to stainless steel and then forgetaboutit...

 

[Captain Kilowatt]

A foot and a half on either side of a 20m dipole?? Are you sure you used wire and not bungee cords? I have had wire streatch but NEVER that much.80 or 160m yes but 20m no.

 

[C2]

he did use stranded.

perhaps the strands had a lot of slack, or perhaps each strand is broken somewhere along the length and it will perpetually slide apart.

You can use solid copper and pre-streatch it...then you can pound on it to harden it a bit...a vibrating sander will also harden it.

 

[WX2MIG]

perhaps the strands had a lot of slack, or perhaps each strand is broken somewhere along the length and it will perpetually slide apart.

This is some really old wire, it came from heavy duty (Fire Service grade) extension cord that spent 20 years on an engine, then another 10 on a utility vehicle, after that it sat around the fire station for several years before the Chief told me to throw it out. The outer cover was completely dry rotted, and cracking apart....(which made it easy to strip)....the covering on the individual strands are still in pretty good condition however when you strip that off the stranded cooper wire is very dis-colored...

I expected "some" stretch, but 18" + is a little much.....

I just gotta trash pick a better grade of wire from now on.......

 

[2at124]

This is some really old wire, it came from heavy duty (Fire Service grade) extension cord that spent 20 years on an engine, then another 10 on a utility vehicle, after that it sat around the fire station for several years before the Chief told me to throw it out. The outer cover was completely dry rotted, and cracking apart....(which made it easy to strip)....the covering on the individual strands are still in pretty good condition however when you strip that off the stranded cooper wire is very dis-colored...

I expected "some" stretch, but 18" + is a little much.....

I just gotta trash pick a better grade of wire from now on.......

There a ham that lives in the outdoorworld camp resort . He is a Ham operator his name is Ed . If you here him on the bands He is great with makin all kinds or antennas

 

[Moleculo]

This is also the reason why you need to check your guy wires every once in a while if you're using just el-cheapo guy wire.

 

[WX2MIG]

There a ham that lives in the outdoorworld camp resort . He is a Ham operator his name is Ed . If you here him on the bands He is great with makin all kinds or antennas

Can't say that I know if I talked to him as yet since most ham's go by their call sign, and don't always offer a name to go with it.

With the short distance between us, I may have talked to him on one of the Cape May County repeaters, but I doubt I'd make contact with him on any of the HF bands unless I run into him on 10 meters......

Thanks for the heads-up, I'll keep an ear out for him......