[TowerTalk] Dipole questions for the Liberal Arts Major

[Tom Rauch]

> I was always instructed by an Elmer to cut the dipole
> long and then use a tuner to tune the higher part of
> the band.  Others have instructed me to cut the dipole
> for about 100 Khz up from the bottom and get  as much
> use as possible (not quite possible on 80 or 75
> meters).

I set mine for the middle of the areas I want to use. On 80
meters I operate 3500 or so and around 3800. The middle is
around 3647 so I set lowest SWR about there.

>Another Elmer cautioned me to make sure I
> solder the ends of the dipole because the wire wrapped
> at the end acts as a inductor with a capacitor in the
> loop of the wire around the insulator which would make
> the resonate point different than calculated.

Well, maybe. I doubt you would notice that effect unless the
loop was larger than normal.

And yet
> another told me to build a large wire diameter dipole
> (out of RG58 or 59 or even RG8) to get some bandwidth.

It's significantly more weight effective to use two thin
wires spaced a few feet apart than one thicker conductor.

> So, with those comments that I have made...what do you
> do when working with dipoles to get them to the point
> where you get good bandwidth?

On 40, it isn't generally an issue.
On 80 I use a fan or "bow-tie" dipole made from a pair of
#16 wires. I space the wires a few feet at the open end.

73 Tom