What should I use to build a center insulator?

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What should I use to build a center insulator?

Postby KF5CSW » Tue Oct 26, 2010 4:07 pm

Hi everyone,
I'm still in the planning stages of my 20m antenna. I'm building an inverted vee dipole, and I need some ideas on what I can use to build the center support/insulator? Plexiglass? I'm not savvy about cutting anything but wood. It'll be coax as the feedline.

Also wondering what I should use as the end-insulators? I'm not finding any insulators in the Electrical section at Home Depot, etc. I'm also going to be building a buddipole design later on, and I'll probably have some extra PVC left over. I'm wondering if I can cut a small slice of PVC, drill a couple of holes in each side, and use that?

John Vogel
SKCC # 7106
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Joined: Wed Sep 29, 2010 3:12 am
Location: Bentonville, AR

Postby KC9KHG » Tue Oct 26, 2010 5:10 pm

Hi John,
I use PVC caps. One eye-bolt on the top for support, and one on each side for stress relief for the wire. I use brass screws and nuts to connect the feedline to the antenna wires.

My center support is my tower,so I just loop the coax down a few feet and tape it to the tower leg. If you don't have a center support,you'll need to have a stress relief for the coax also.

As for the end insulators...I don't use any. I just tie the rope to the wire. I have read that you shouldn't do this,but I haven't noticed any ill effects. If you want,you can get some small PVC pipe,cut it to 2" or so,drill holes on each end and feed the wire in one end and the rope in the other.

Good Luck and hope to catch you on the air!

SKCC #3687Tx6
WCC #281
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Location: Woodstock,IL

Postby NT9K » Tue Oct 26, 2010 7:33 pm

Hi John, I built my first one by cutting off 4 inches from Mom's broom handle. I wrapped it in electrical tape and drilled a hole in each end. Then I wrapped the coax around it the taped it together. Here is a picture:
73, Bill - NT9K
SKCC #1926c69t9was8hofdxq2dxc1
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Joined: Sat Apr 01, 2006 9:25 am
Location: Melbourne, Florida, USA

Seal it up really good

Postby W2BLC » Wed Oct 27, 2010 12:47 am

When you have it all constructed you must seal everything up to keep moisture out of the coax. My recommendation is three coast of Liquid Tape - available in most hardware stores.

Allow a half hour between coats and be generouse with the coverage.

I seal my antennas every fall and have never had any problems - some have been up for many years.
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Joined: Sat Feb 04, 2006 1:36 pm

Postby k8jd » Fri Nov 04, 2011 11:42 pm

I would try working with 3/8 inch plexiglas stock you can find at bigger home improvement stores.
Easy to work with and lasts longer than wood in an exposed enviornment.
Just drill holes for the wire and coax to go thru.
I have some old antennas that this was used in and the wire wore out before the plastic.
73 from K8JD, SKCC 1395, Centurion 18, Tribune 12, Band Endorsements; 160, 80, 60, 40, 30M, 20, 17, and 10M

Ham radio is real Radio, CW is real Hamming!
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Joined: Fri Feb 24, 2006 5:15 pm
Location: Commerce, MI

Postby Guest » Wed Nov 09, 2011 8:50 pm

I found a simple sched 40 pvc works wonders and holds up. Here's a simple of center and end insulators for coax or window ladder feedline.






For end insulators, nothing beats cattle wire insulators. They are designed as a insulator outdoor mounting, holds up to heat/sunlight and is light. they are more durable than MFJ or similar glass insulators





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