The AM Forum

Hi Guys, I am looking for a tool that will easily cut out the solid spacers used in window line. I want to once I have  removed the existing spacers to install 4 inch spreaders, made from electric fence insulators that use the "wire ties" approach.

If I could find something that would heat off a propane torch that would melt and cut those panels out, it would be great! I have seen somethings on the web that may work but they go for big $$$'s. I want to re-use what I have because I already own it and it's 13 gauge very tough stuff. I like the heat and cut approach because you stan less a chance of nicking the wire which is copper clad steel. A nick here and there will lead to rust and we don't need that! Maybe a nichrome wire and a car battery would work? Any ideas out there?

Thanks Terry

Some background..I use about 250 feet of OW. Rain, snow and Ice are a big problem with it. It works great in sunny weather :o :o :o 

https://www.ebay.com/itm/NEW-130W-HEAVY-DUTY-HOT-KNIFE-CUT-CUTTER-PLASTIC-FOAM-NYLON-WAX-ROPE-FABRIC/131250749231?epid=1831330470&hash=item1e8f277f2f:g:g84AAOSwwNVTuJd-

This setup looks like it might work.  Just be careful that the cost of the cutter doesn't end up being more than the price of 500 new feet of wire.   Real open wire line is good stuff and, while not perfect, beats the bad-weather performance of "crappy brown stuff" balanced line.
This evening in Maine I had over 1/8 of ice on the line feeding my two-element 80m phased array.  It pushed the unity SWR point from 3.8 nicely down to 3.53.  A twist of the wrist on the tuner solved the problem.  I build mine with pigmented UltraEthylux plastic that I got as scrap from a broadcast FM radome project, but it's available from McMaster as well.  My UltraEthylux spreaders have been up well over a decade, holding #12 Flex-Weave wire and show no signs of degradation.

Yep, I hear you.

I had 100' of 300Z window line and it rained the very first night it was up. I had to keep retuning to restore a match until I decided to go out and see what-in-the-world was going on. A solid whack with a broom resulted in a downpour of what seemed like gallons of water droplets that had remained within the slots between the conductors. Tuning went back to where it started, then the issue returned.

The next day I took the line down and used a box cutter to remove the separators. This took some time and a steady hand to follow the leads carefully, then I used 4" Fyshock insulators and UV resistant cable ties to make my own open wire line.

Couldn't be happier with it. You will be too!

Woo, those are nice boobs, I mean knifes. I think I seen something like that at Horrible Freight here in Albany, NY. 

They say in springtime a young man's heart turns repairing your OWL. I think that's how it goes? Well anyhow, two more months and maybe a couple weeks and it will be repair time...

I once mounted a utility knife blade in a vise and just pulled the window line passed it. Worked ok but you hafta trim later! Took time but no money!

Doing that is  a lot of work.  Consider buying some Flexweave wire and the insulators you have chosen.  The Flexwave does not have problems the old stuff did.  I have antennas made of it up and have been for 10 years without problems of breaking or sagging much.

In bulk it is pretty well priced.

https://www.thewireman.com/antennap.html

Thanks for the link Jim. I am going to stick with my plan. I need to drop the antenna and then put it back up. It's cut for 1.885 or perhaps a bit lower. It's way up in some 125 foot pine trees at about the 80 foot level. I have about 500 feet of the stuff so I'll use 250 feet for each antenna. The one up right now is broadside east and west. I want to put up another broadside north & south. They will be about 200 feet from each other. Maybe I could load both at the same time and cover all point in between? Just joking about using both at the same time but it would be interesting seeing the results! I figure that it will take about 8 hours to do the one that's up and maybe about 12 hours for the new antenna. It's harder that some folks think doing antenna work by yourself :'( :'(

Get some bare #12, and a pack of Zareba fin tube insulators for electric fence work.

Cut them into 2 inch lengths, and space wire 1.5 inch.  Zo should be around 430 ohms.  Make up some little jog to cut and drill them all just the same.

Use a spacing interval in the 18 to 24 inch range.

Doubt your tuning will change.

Is that ever the truth.  I have a 60 ft. free standing tower that I put up by myself and 75/40 meter dipoles at about 50 ft. along with a inverted L on the opposite side of the support.  The worst part were the radials.    At my age it was a long, hard task.

wonder if rainx would help?

Is this that spray on product? I guess if your feedline was low enough you could put it on otherwise you would need a surplus airplane de-icer 8) 8)

There is or are products that cause water to run off surfaces.
Rain-X is non-permanent.

Rustoleum was selling a 2-part spray that did this trick.
Hydrophillic coating, I think that is what it is called.

In theory you could perhaps spray the crappy brown stuff with it, and water
would not stay on the surface.

There are likely other sources for the stuff... or just get the hot knife cutter and wear a
respirator - breathing plastic fumes is not good.

                                                            _-_-

The most dangerous emissions can be caused by burning plastics containing organoch- lor-based substances like PVC. When such plastics are burned, harmful quantities of dioxins, a group of highly toxic chemicals are emitted. Dioxins are the most toxic to the human organisms.

Mmmm Dioxin

Your easiest bet is to go buy a box cutter.  And a box of razor blades.

Put one end of the CBS in a vice, tie it around a trailer hitch, etc.  Pull the other end taught.  Best to use the two wires around the hitch and whatever else you use to keep the line taught.

Now, run the box cutter down the line, and cut the 'BS' (brown stuff) out.

Done.

Change blades frequently to keep them sharp.

No hot knife needed.

I used the same method to cut insulation from tens of thousands of feet of wire as an electrician apprentice.

Not really sure what a hot knife would help with, other than letting the knife wander around in the 'BS' more easily.

Once the 'BS' is gone, you can leave the wires where they are and snap your spreaders in.


--Shane
KD6VXI

I wonder how a wide blade very sharp wood chisel would work? Get a bunch of old 2 by 4's
and give the panels a whack! Maybe greenwood would be better fer whacking?

Whack-o-matic!

Sure, it's the same method they use to make the "window" originally.

No need for a wood chisel, think you want a Bricklayer's chisel, it's wide.
Or you could just buy a scrap bit of steel down at the Metals Supermarket down
on B'way, north of Nipper... grind one edge down at a 45 deg or so sharp edge and
whack the steel , like 1/4" thick steel. Heat treat for hardness if you wish.

I'd hold the thingie with a vise grip to keep my paws far from the "wacker". :D

            _-_-

How about making a simple jig like this?

A slot that just fits the thickness and width of the twin-lead, and a blade inserted at its end, so that the whole length can be drawn through the contraption.

The longer the slot the better it would make sure the twin lead does not twist or get too mis-aligned and jam.

Cost to make is almost nothing but a few hours, and the cut should be uniform. It could be made of wood or of old circuit board material stacked up. 

N.B. it's just an idea and I have no idea how it may work, well or poorly.

How about a pair of tin snips.

Thanks Patrick, Looks like that could work, Using tin snips is a problem as the cut would leave a little uneven edge. That is tough stuff unless its heated a but before cutting. I guess I am too particular in doing stuff like that and the reason is that I suffer from doing fine work. Everything I home brew looks like home brew as I am not good at being exact at things I do. There are others on here that do perfect work like K1JJ and Joe Wa2PJP as examples. Now I know that it's just open wire line and that no one other than me will see it but I have that fobia.  


I need to see an open wire shrink ;D ;D ;D