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Author Topic: Jackite guying recommendations?  (Read 2963 times)
K7NHB
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Posts: 230




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« on: March 02, 2013, 05:34:42 PM »

I'm putting a 29 ft Jackite (tapered telescoping fiberglass pole) up in the corner of the back yard where two fences come together. This would be for an inverted L longwire to operate at most 100W on 40 - 6M (if I can get on 6M - mostly 40M to 10M).

My first thought is to put a 44 ft long wire up it (29ft vertical, 15 ft horizontal). I could support the 15 ft piece with  some small kevlar line continuing to the house. But then I thought that instead of rigging up a weight and pulley mechanism at that house - so the #18 wire would be part of that support, I could just run the non-stretch kevlar directly from the house to the top of the pole. I could just string the extra 15 ft of insulated #18 antenna along the kevlar line.

The Jackite can get a bit if a whip in strong wind. The single line coming off horizontally from to top would stop that somewhat. My concern is, if the wind blows it towards the house and it comes back with a snap, it is abruptly stopped by the line.

But does the wind really work that way. If it was pushed towards the house, I'd think it would not abruptly be released to spring away.There is very little wind load at the top.

It is difficult to guy at the sides because that presents a downward force which eventually cause the sections to collapse. I do have each section taped and most have an additional plastic clamp to keep them from premature collapsiation.

Should I really be concerned about that one guy line?

Is there any benefit of going to the next "magic" length (52 or 58 ft). I understand that 44 ft is very tuner friendly. I'll probably run it through a 4:1 Unun.

Thank you,
Paul
K7NHB

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W8ATA
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Posts: 327




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« Reply #1 on: March 02, 2013, 07:31:56 PM »

I just want to comment on your valid concern of collapsing the sections if you use guys with a downward tension. I have done similar supports with telescoping masts and have drilled a 1/8" hole at each overlap joint and used a stainless machine screw and stop nut to prevent collapse. Good luck.

73,
Russ
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K7NHB
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« Reply #2 on: March 02, 2013, 10:07:43 PM »

Russ,
Were you able to drill through the fiberglass with a normal "craftsman" type drill?
Any special precautions or treatment of the sections after drilling?
73,
Paul
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K4PP
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Posts: 67




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« Reply #3 on: March 03, 2013, 05:02:34 AM »

I use a Jackite mast and two 20' blackwidow poles to make an inverted V but only in a temp backyard setup. The Jackite is wire tied to an expandable base tri-pod and the two blackwidows are slide over a ground stake hammered in the ground. On a breezy spring day, this assembly can get flappy as a wet noodle if it isn't loaded up right mechanically.

It might work better if the Jackite were based to the fence and loaded up hooked over toward the house just like those mobile antenna's you see on the trucks. That way, as long it the additional wind load won't break the mast, it always has a load on it to return to resting position without swaying all over the place and the wind load has to exceed that preload to move the mast. Maybe you can get that 44' wire back to the base without it being totally vertical.

Just a thought.

K4PP
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N3OX
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« Reply #4 on: March 03, 2013, 08:15:59 AM »

I have done similar supports with telescoping masts and have drilled a 1/8" hole at each overlap joint and used a stainless machine screw and stop nut to prevent collapse.

With the low cost fiberglass poles like the Jackite? I've used a lot of telescoping fishing poles and would never even think of drilling a hole in them; they're fragile and when a split starts you can't stop it. But I haven't used a Jackite.
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73,
Dan
http://www.n3ox.net

Monkey/silicon cyborg, beeping at rocks since 1995.
W1JKA
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« Reply #5 on: March 03, 2013, 08:33:39 AM »

 For telescoping fishing poles (Cabelas crappie poles i.e.) I use a small 5/64 drill bit for hole about 1 in.  above bottom of section and held in place by large half open paper clip,no problem.
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AG6WT
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« Reply #6 on: March 04, 2013, 07:47:35 AM »

I've have used Jackite's 33' poles in a similar fashion for 3 years now: mounted to the corner post of a fence and extra wire pulled toward the house to make an inverted-L.

First, the pole is too flexible to support 18 awg wire unless you have a guy pulling in the opposite direction. A better choice is 26 awg polystealth wire with the end finished with fishing line to the house. For the fishing line I like 20-30lb test Spiderwire braided line. I don't use guys for support but I do have one dacron line tied to the pole about 20ft up in the direction where I get the worst wind gusts off the ocean. The far end of the inverted-L is tied off with just enough tension to bend the pole a little. I have tried a pulley and weight but found the pole whips around in high winds more this way.

It is safe to drill the pole to put in screws. I have 2 poles and drilled both with a small bit (3/32" if I remember right) and never had a problem with cracked fiberglass. Use a fresh, sharp bit and apply light pressure. Make sure the hole is matched to the screw. If the hole is too small, the screw will split the tube. Alternatively, you can use cable ties. Put one cable tie just above the joint, tightly on the bottom of the smaller tube. The cable tie acts like a belt and will keep the sections from collapsing
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K1CJS
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« Reply #7 on: March 04, 2013, 08:36:15 AM »

...The Jackite can get a bit if a whip in strong wind. The single line coming off horizontally from to top would stop that somewhat. My concern is, if the wind blows it towards the house and it comes back with a snap, it is abruptly stopped by the line.

But does the wind really work that way. If it was pushed towards the house, I'd think it would not abruptly be released to spring away.There is very little wind load at the top....

The way the described poles would whip would certainly be a concern.  I've seen fiberglass poles continually whip back and forth when the wind is blowing.  Whether or not you're going to use non-stretching line, you're going to need either a decent spring arrangement or a weight and pulley system at one end to prevent tearing the messenger line off of either the house or the pole.  To try such an arrangement without either a spring or a weight and pulley is asking for trouble.
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K7NHB
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« Reply #8 on: March 06, 2013, 10:02:45 AM »

Thank you for your excellent suggestions.

Just to clarify a few points - though the Jackite is 30+ feet full length, the very tippy top is a thin small diameter shaft of fiberglass. I would not hang #18 off that. But I am not using that top piece. I stop one section down. And the to "L" of the inverted "L" is only about 15 feet long - not so heavy. The nylon covered Kevlar is also small but plenty strong with no stretch. So I understand the need for a shock absorber.

But I'm afraid any pulley/line situation could freeze up in our weather and become static - loose its purpose in life.  So I'm leaning towards a bungee cord ideal - like that used on camping tarp guy lines. That is - a fix line with slack that is taken up by a shorter bungee. If the bungee stretches too far (usually twice its unstretched length) the fixed line stops it from going further. I did see some fishing line in the garage. The 30-40 lb. test would be very light but I wonder about durable with a lot of UV exposure. The connection to the house would be up 20 ft - not accessible with my 16 ft ladder and a 20 ft fall if I try to reach it from the roof top directly. So I'll borrow/rent something to get me up there and I hope not to have to make a return visit for a long time. In fact, I maybe I could just use a longer tether and find suitable anchor on the roof top instead of the eave.

I wouldn't think you could zip the zip-ties tight enough to act as a belt; but I suppose it doesn't take much to enhance the standard locking. LDG sells their own mast - a bit heavier than Jackite - and it includes ratchet clamps for the joints. I bought the clamp set separatly and they fit all the Jackite joints except one. Later I found that Ace Hardware carries the same type of clamp so I'll see if they have a size that covers the diameter that the LDG set missed (the LDG set is for their own pole. I was just hoping it would work on Jackite and I didn't know about the Ace Hardware option}.

I also tape each joint with high quality (UV resistant) electrical tape. I wouldn't do that for field work but this is for a non-temporary situation.
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K1CJS
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« Reply #9 on: March 07, 2013, 04:41:54 AM »

Just a couple of further suggestions.  If you're not going to use the top section and intend to leave it retracted in the second section down, you may want to look at putting some sort of packing at the bottom of the second section to stop the inner mast from knocking against the outer one.  If you don't it may result in having a really annoying 'tapping'--or even a banging noise whenever the wind is blowing--you'll hear it through the messenger line connection.  Remember two tin cans and a string as a makeshift "telephone"?

Also, a bungee cord may be too light--depending, especially after weathering and constant use.  Most of the bungees you spoke of are for temporary or short term use only.  They really don't weather very well.  

I've used a wire cable and pulley with a really stretchy spring after the weight with good result.  The wire tends to resist icing unless you get really heavy, wet wind driven snow blowing.  Even then, usually it clears itself because of its constant motion.

I wouldn't use fishing line either.  It also doesn't weather very well (sun exposure) and will snap just when you need it most--even the higher test strength lines.  Zip ties as a belt/lock could work, but a mechanical clamp is way better.  If you want to tape the joints, go ahead--but the taping may serve to hold in moisture (no taped joint is entirely waterproof--except for the water that is trying to get out!  Roll Eyes ) that may well affect the clamps you use.

Good luck and 73!
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KC7YE
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Posts: 104




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« Reply #10 on: March 07, 2013, 07:15:55 AM »

Have MFJ 33' mast and just completed month long deployment in desert (snow birding). Mast survived wire(s) did not. # 22 stranded inverted L for 160 broke a couple of times. ended up with 33' taped to mast & no 160. Electrical tape holding wire at each slip joint kept mast from lowering. 50 - 70 MPH did in the L. Figure if mast breaks, it breaks. L was way too much wire for this type mast.
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K7NHB
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« Reply #11 on: March 07, 2013, 12:49:32 PM »

The "tip" of the Jackite, in fact all sections, can be completely removed from the setup via a screw-off cap at the bottom.
I do plan to tape the wire up the pole. to the 29 ft level (tip removed, top covered with tape). From there, I have a hose clamped plastic ring through which I'd run the horizontal part of the "L" and attach the guyline horizontally to the house.

I picked 44 ft because I was told it was "tuner friendly", especially if I bring it to a 4:1 unun that's connected directly to the tuner located at the antenna base (coax to the house). I plan to operate mostly 40M - 10M and 100W or less.

If the antenna modeling guru's out there say I'll notice very little difference between 29 ft and 44 ft and the LDG tuner can match 29ft just as well on 40M - 10M, then I can do away with the "L" component. If I ran a "sloper" instead of the "L", I'd still have the whipping issue.

Paul
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