Farm stores and hardware stores in farm territories often carry toroidal
shaped ceramic insulators with a groove around the outside that make
decent antenna insulators. Sometimes they are only sold by the box of
ten or twelve but costing similar to special antenna insulators by the
unit price.
The loop of wire around an insulator will make the antenna resonant at a
slightly lower frequency with a wider bandwidth.
Power companies go for a light gray wire color to hide it in the sky
more often than blue.
73, Jerry, K0CQ
On 1/12/2011 5:45 PM, Stuart Rohre wrote:
> Tom,
>
> Many wires will work at 100 watts. For stealth and durability, stranded
> no. 22 light blue insulated hook up wire will work if your feedline is
> supported to not put weight upon the flat top wires, (elements) of your
> dipole. You could also use up to no. 14 ga conduit wire, insulated in a
> light blue to blend in against the sky, if it is in the back yard, and
> less visible, therefore from the street.
>
> Even bare stranded no. 14 wire, widely available, and at Radio Shack, as
> well as at ham suppliers like The Wireman, and Coaxman, will make a low
> profile dipole. The bare wire eventually oxidizes black, but that does
> not affect the conduction which is under the coating. If you have
> soldered your feeder connections, that is, when the wire was new and
> shiny. 14 Ga. can support twin lead or ladder line feeder strain
> relieved to a center insulator.
>
> For end and center insulators, I have used for Field Days for year,
> white vitamin pill bottles. You can punch holes to hold a synthetic
> line halter for the end tie offs, and two holes to pass the end of the
> dipole element through. Or course, more durable plastic insulators
> could be made from PVC 1/2 inch plumbing fittings, or commercial ceramic
> insulators can be purchased from the Wireman or Coaxman or ham
> distributor stores. Make sure to buy glossy, glazed ceramics if going
> that route. Another way to secure end halters to the pill bottle is to
> simply drill the cap, and knot a line inside the cap, pass the line thru
> the hole and screw the cap on the bottle. Then you only need two holes
> in the bottom of the bottle sides for the loop of the wire element.
> Don't worry about the inductance of the loop of wire, it will only add a
> capacitance hat effect, as it connects, (solders) back onto the standing
> part of the end of the wire element.
>
> For your line to hold up the ends, pick a UV resistant material. Nylon
> will stretch, and work for a couple of years, but you might as well
> spend a little money on the better line materials that will resist UV.
> The white plastic pill bottles hold up pretty well, but are easily
> replaced if they tear in a wind, or decay due to weathering. Ceramic
> insulators, if not dropped on hard surfaces, should last longer than
> your antenna wire, and feedline. I use some from 54 years ago, at the
> start of my ham career.
>
> Home center stores usually have anything you need to make a very
> workable and economical antenna.
>
> GL and 73,
> Stuart Rohre
> K5KVH
>
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