Cheap Homebrew Ladderline Spreaders

[Northmountain]

By Zac Taylor on eHam

Living in a bowl high in the mountains of Montana has given me many obstacles to overcome in my quest for contacts. Since I operate barefoot, I need all the signal possible to get out. Getting the antenna high enough in the bowl for a decent take off angle, means very long 300'-500' feed lines from my cabin, so coax feeds are far too costly or have too much loss over the distance to use. The loss due to snow and rain in the winter makes 300 ohm and 450 ohm window-line prohibitive as well. So 3 ½" spread open-wire ladder line has become the best feed-line I can muster.

I have tried all kinds of homebrew wire spreaders, waxed dowels, ceramic, cut up plastic clothes hangers, PVC pipes, and until today the winner in cost and longevity in our harsh winter weather was cut up feeder tubing for swamp coolers. It was strong and UV resistant, and average cost was at about 20 cents a spreader. It is glossy so reflects in the sun a bit, but not too bad for price and availability.

Today however, I found better way. These items were made to be UV resistant, made for harsh weather and abuse, already cut to 4" each and thus ready for immediate drilling. They even have special fins to stop tube collapse under high strain such as wind or weight due to extreme wire lengths.

I am referring to off the shelf electric fence "4 Inch Fin Tube Insulators", by Zareba. You can find them at Murdochs or any major farm supply type of store, and at $5 per hundred the cost is dirt cheap at a nickel a piece.

Drilling them was much easier than most other tubing or round stock. I made a jig on my drill press out of a 2x4 with my router, making a groove the 4" length at a depth that let the piece sit with the fins flat against the wood. This held each tube in place with one finger eliminating the rolling inherent to round stock that often makes difficult drilling the holes perfectly parallel.

The fin also made it easy to extract the piece with a fingernail from the jig, to switch position to drill the other side at the exact same inset. No measuring is needed once the drill is set at a ¼” (or any width you want) inset from one edge of the groove in the jig.

You just drill-flip-drill-extract, and insert the next piece. I drilled a hundred in a few minutes time. I drilled each hole one fraction larger than wire I was using, so it would be threaded easily. Now, this deviates from what many would say is the best practice. Most home-brewer’s I spoke with recommended drilling slightly smaller so it grabs the wire, and they use a cutter or saw to add a slot on the side or end, allowing the wire to be "snapped" into the hole. Then they use wire tires or glue stick to make the spreader unmovable.

Since the glue stick step was inevitable for a really slip free connection, I decided I wanted to eliminate the labor of the notching process. Drilling the hole larger not only made feeding the line easier, it gave room for the glue to express slightly out at each connection.

Next I ran the wire through the pieces, positioning each at approximately 12", and rolled the feed-line up, placing it on a table so I could unroll the wire a foot at a time for the next step.

Using a HIGH HEAT glue-gun with HIGH HEAT glue-sticks, I unrolled the end off a table handling each spreader one at a time. I positioning each spreader as it hung of the table edge to be straight across at its 1' distance, then shot glue into each end of the piece until I saw it ooze a little out each wire hole. Once it cooled it made a "T" of glue, with the main part in the tube going around the wire, and the small flanges in the wire holes themselves. The "grab" was very solid. The completed spreaders and feed-line simply rolled off down under the table as I unrolled the feed-line from the table. Towards the last few, I placed a book on the wire ends and slid it until I finished.

The emphasis above on HIGH HEAT glue-stick is because if I ever run an amplifier, I don’t want to worry that the heat of the power on the wire might loosen the spreaders in summer weather. I have no worries about it here in the winter, as things stay pretty frozen. One other nice detail about the insulators is that the black color is matte. No glare off of them in the sunlight.

I'm pretty new to HAM, and I hope this helps others both save time and expense, who might become interested in true ladder-line. With the long runs to my antenna's here, it became imperative I use it…

73
Zac
W7ZAT
Zac A Taylor (W7ZAT)

[M4wilson]

Wow thanks. I love the low cost and well thought out solutions. I need to finish my studying for my HAM license...