I use Aircraft stainless steel control cable for my inverted V's / slopers.
They are tight and sag is minimal since I also use them as guy wires. I
install them fixed at the top of the tower and allow for tuning by moving
the egg insulators on the ground end.
> -----Original Message-----
> From: email@example.com
> [mailto:firstname.lastname@example.org]On Behalf Of N6FD
> Sent: Friday, December 31, 2010 12:58 PM
> To: email@example.com
> Cc: Tod - ID
> Subject: Re: [TowerTalk] Non-sagging antenna elements
> What I suspected here was that when the wire antenna was put up, sag was
> minimal. Then it began to droop further as time went by. This is due
> to the wire lengthening under load. I experienced this a lot in my
> teenage ham days when I was using copper bell wire to build antennas.
> And it does change the resonant frequency. Eventually I had to replace
> the wires when they stretched to the breaking point. The other effects
> of droop occur as well.
> 73, Erich
> On 12/31/2010 10:25 AM, Tod - ID wrote:
> >> One thing to realize is that the resonant
> >> point is changing because the wire is also getting longer as it sags.
> >> 73, Erich
> >> N6FD
> > I wonder if you mean that the apparent length of the wire is increasing
> > Erich. I suspect that the actual length of wire is not really
> changing -- at
> > least not significantly -- when the wire is sagging. The
> capacity to ground
> > is probably increasing as the wire droops toward the ground. I
> guess that
> > would be one form of capacitive loading.
> > Tod, K0TO
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