Monday, November 10, 2014

Dipole Back Up!

I wrote back in May that my 80/40m dipole had fallen down when a tree branch broke off and came through the antenna.

While there was no real damage, it did dislodge the rope anchor I had cast over the tree. Because it is so difficult to cast a line into the trees when the foliage is out, I had to wait.

It was fortunate, however, that I did wait. During the summer storms, this same tree shed a couple more large branches. Well, the leaves have thinned out considerably from the trees, and I've actually been out in the woods a couple of times to cast a new line.

Those sessions didn't end well. You see, I'd go out with a weight made of a 1/4 to 3/8" bolt and a few nuts, and on the first cast, I'd lose them. They came sailing off the end of the line, never to be found.

Assembled parts for the antenna launch weight
As I wrote about the Mark III Antenna Launcher, losing weights is inevitable. Given the beautiful fall weather we had this weekend, I decided I was not going to have my antenna raising session interrupted by a single lost weight.

Normally, I'd recommend you construct these antenna weights with hardware you're not likely to use for anything else. This likely means old, corroded nuts and bolts that you've taken off some old assembly. However, I did not have much of this kind of hardware on hand at the Micro-Shack.

Technique for jamming nuts together
Time to fight back with numbers. A quick trip to the local home improvement store found 100 1/4" nuts and a dozen 1 1/2" long 1/4" bolts for about $8. The plan was to jam on as many nuts as the bolt would allow. This would make for a reasonably heavy weight, but one that would fit well in the slingshot pouch.

Assembly is easy. Simply screw the nuts on to the bolt as far as they will go, and repeat. I managed to get six nuts on the 1 1/2" bolts, although I did have one overachiever bolt that received seven.

The finished product. A dozen weights, most with six
nuts, one with seven.
Once the nuts are on the bolt, but loose, take a couple of wrenches and jam them down on the end of the bolt, and then one against the other. Make them tight enough that they won't go flying off when launched into the air.

Less than 20 minutes later, I had a dozen antenna weights. Filled with confidence, I marched outside fully prepared to lose numerous weights in order to get the dipole in the air.

Naturally, given my readiness for sacrifice, I managed to get the line over the tree branch on the first shot. I didn't lose a single weight. Well. I am now prepared for the mid-winter antenna raising season.

I am very happy to have this dipole back up. I have missed it all summer.

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