DIYing a QRO cobwebb

[NH7RO]

Thanks guys, but I'm not much of a net guy. I never know when I'm going to be operating and I am usually on just looking for elusive DX when I do.

Charles, KC8VWM was the one who got me going with the idea of a cobweb and he is a strong proponent of their use---I thereby nominate him for Cobweb Net Control...

By the way, Ken, those adel clamps look like a good way to go for wire mounts although I still like Charles's idea of dacron rope with epoxy; so minimal and easy.

73, Jeff

[NB9A]

It was a joke. I am not a net guy either for almost the same reasons Jeff. Just trying to kill time on my end. And I like the idea of the adel clamps but I worry about the affect it might have on the antenna itself.

[NH7RO]

I imagine the effect of the metal in the clamps would be minimal but I am inclined to go for rope or well-protected cable ties (the electrician's kind with the loops) for element mounting.

Still waiting for some better than usual propagation here. Once we have an opening on 10, 12 or 15 I'm going to put my cobweb through its paces. I got spoiled with all the DX that rolled into KH6; logged 144 DXCCs on 10 meters alone in less than 2 years time. Here in NM I've heard about 6 stations total on ten and PY is about the best DX at that. Oh, well, summer doldrums I suppose.


73, Jaded Jeff

[W7KKK]

Maybe I have just got back ones but I have seen the 7-9" variety of black UV protected cable ties fail in this harsh UV we can get here in AZ.
After about a year they get brittle.

[NH7RO]

Hi Ken; By well-protected I mean covered with marine epoxy and/or a few turns of electrical tape so that no part of the cable tie is exposed.

Unprotected "UV resistant" cable ties will get brittle and crack in a couple of months easily around here.

73, Jeff

[W7KKK]

Yes I would suspect your environment there is as tough as mine and that's more or less why I quit using the ties around here.
I think the adel clamps would be OK but on second thoughts the rubber that clamps on the poles would rot out too.

[KC8VWM]

Thanks guys, but I'm not much of a net guy. I never know when I'm going to be operating and I am usually on just looking for elusive DX when I do.

Charles, KC8VWM was the one who got me going with the idea of a cobweb and he is a strong proponent of their use---I thereby nominate him for Cobweb Net Control...

By the way, Ken, those adel clamps look like a good way to go for wire mounts although I still like Charles's idea of dacron rope with epoxy; so minimal and easy.

73, Jeff

Since this is all my fault in the first place, we'll see what we can do.. lol

[KC8VWM]

Yes I would suspect your environment there is as tough as mine and that's more or less why I quit using the ties around here.
I think the adel clamps would be OK but on second thoughts the rubber that clamps on the poles would rot out too.

Ken, the main reasons I opted out from using these clamps was because:

The fact these clamps would not hold up for the long term in the outdoors.

The metal on the clamps would probably rust and the rubber would crack and rot.

The additional weight of installing 20 of these clamps on the spreaders. (this was originally intended as a lightweight portable antenna)

There are cheaper and more lightweight alternatives.

Other thoughts I had included the idea that the metal on the clamps would be introduced into the immediate radiation field of the antenna. I was thinking this might introduce a "capacitive detuning" aspect for the folded dipole elements I was using (in my case the G3TPW design) or the idea that installing 20 of them on all the spreaders might skew the radiation pattern. To what extent this might occur is not entirely known, however I felt it was best avoided in the first place. Guess I didn't want any metallic objects installed in direct proximity to the antenna elements if that makes sense.

Of course there are a number of ways to install (secure?) the elements on the spreaders. I came to the conclusion that actual cost, weight and protection from UV degradation were the important considerations. Dacron loops would cost the least since you are already using it for the construction of the antenna anyways. Scrap left over pieces could be made into small loops attached to the spreaders and would serve to suspend the elements. Whatever you use, painting or coating it with something would definitely increase it's longevity and resistance to any outdoor harsh environment it would be introduced.

Ken, it's a fun project that's well worth the effort. When done right, these antenna's are practically indestructible and last for years and years to come.

Speaking of indestructible, I would like to share that I was working on mine recently and it was sitting on top of a 15 foot telescopic pole. It was unguyed when a gust of wind came and the tripod holding the pole tipped over and the antenna came crashing down to the ground like a kite on a string does a nosedive into the ground. I am happy to report this fall had no effects. After a careful inspection, no damage of any kind was noted anywhere on this antenna.

Although, not intended, I guess I can now officially call this my antenna survivability testing huh?

[NB9A]

Quick update.

All of the parts that I ordered have finally arrived. So I should be able to start building this weekend. So far the only work I have done is sanded, primed, and painted the fiberglass fishing poles. I have identified one problem so far that I am not sure if Charles has had. I noticed on your thread Charles that you ended up wrapping the end of the poles in tape and shrink tube to prevent wear and tear. I might have to do the same but not for wear and tear but for the poles to fit in the hub. It seems that since I purchased the smaller (10 ft) and not the bigger (13ft) poles, the ends(diameter) are slightly smaller as well. This creates a huge gap when inserting them into the hub. Will update more this weekend when I really get to work on it.

Chris

[W7KKK]

I think I would coat the ends with a good expoxy.
My build is pretty much ready to go now and it's all here in a box but I have put mine on hold.
I am tired of fighting landlords for "mother may I" and such for my antenna projects so Monday I go fro pre approval on a loan and I am going to buy a home. The interest rates are cheaper right now in that the payment is far less than what they rent an equivalent home for anyway.
When we sold the last place 4 years ago down south I was convinced at our age it just was not worth owning anymore but I have proved myself wrong.
Hopefully by the end of the year we will be in our own place. There are certainly lots of them for sale around here.
In the meantime I have all my notes and parts pretty much ready to go and it may be the first wire in the air at the new place.