Jim Brown wrote:
> On Mon, 19 Oct 2009 23:35:52 -0400, W2RU - Bud Hippisley wrote:
>>> The only problem I've seen with either THHN or ROMEX is the stuff is
>>> soft and your 75 and 160 meter antennas keep getting longer, and
> There's a practical limit to the stretching, but it does happen. I
> recently lowered and trimmed an 80M dipole that had lengthened enough
> over two years to shift it about 150 kHz down in frequency.
> There's also an "upside" the use of ordinary copper wire -- that stretch
> can absorb some of the stress when the wind blows!
> An easy solution (for solid copper) is to hard draw it. Buy #10 or #8,
> tie one end to a rigid object (telephone pole, etc.) and the other to
> your car bumper, and pull it slowly until it breaks. I've done this. It
> works fine.
To get the most out of it, just pull it. One man can work harden #12
while it might take two to do the #10.
Like above you fasten one end to a solid object. Hook the other end to a
"T-bar", piece of pipe, 2X4, or what ever and then pull. Initially the
wire will stretch easily for a few inches, but then become more
difficult to pull and then much more difficult. Stop at this point. It
doesn't take long to learn the proper feel. The problem that can be
experienced by pulling the wire to the break point is irregular diameter
and thus different areas will have different strengths. Under normal
tension for most wire antennas this isn't a problem, but if like me you
pull then as straight as you can get them with the weight of a balun and
the coax to it in the center of the antenna it can be under
considerable tension. For those I just use antenna wire or copper clad
steel as I've busted (pulled the wire in two) a number of them when
using soft drawn electrical wire.
> Jim Brown K9YC
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