No More Balun Pigtails
BALUN PIGTAILS CONFUSE ME.
I honestly have no idea how to allow for pigtail lengths in my OCFD antenna.
In a center-fed dipole, it really doesn't matter. You just make them the same length and then trim the two dipole halves for resonance.
I find the best way to deal with pigtails in OCFD antennas is simply, DO NOT USE THEM.
Yes, nearly ALL commercial OCFD manufacturers use baluns with Pig-Tails, but look closely at their specs - they do not cover 15m. Precise positioning of the feedpoint is critical in order to enable 15m without losing other bands. Pig-Tails represent a big unknown (size-dependant) when designing a multi-band antenna.
DOWNLOAD
This document shows you how to avoid using Pigtails with baluns which were foreseen to be used with Pigtails.
Modified Balun Box - No Pigtails.pdf
PDF-Dokument [348.1 KB]
EXAMPLE:
MODEL 4115t
Here you can see how I have removed the loops on the side and moved the connection bolts to the top.
The wires will fasten on the top, wrap a couple turns around the [dummy] ears on each side and be secured with a black UV-resistant wire-tie.
This is perfectly sufficient for use in an Inverted-V configuration.
RED ?
It is fingernail polish. If the balun happens to be mounted fully horizontal, tiny puddles of standing water on top of the balun can create a high-resistance short between the two terminals, modifying the SWR. Several thick coats of fingernail polish (any color - but not metalic), will prevent this.
Other Methods
This Home-Brew balun has its wire connections on top and strain-relief on the sides.
The two black "ears" left and right are dummy bolts with heat shrink tubing over them. The heat shrink tubing used has hot-glue inside, enabling it to bind securely to the bolt. The wire legs wrap around these ears once or twice, then are secured with thick (black) UV-resistand wire-ties.
If you also slide heat shrink tubing (with hot glue) over the first (short) portion of the wire, then secure to the ear with a thick UV-resistant wire-tie, you get excellent strain relief and know exactly how long the wire is.
The balun shown here is a 4:1 Hybrid balun of my own design.