On Wed, 24 Jan 2018 08:33:55 -0800, johndusek3 wrote:

+AD4
The antenna comes with 100 feet of 75 ohm balanced-line for
+AD4 the feed line (very thin/small)

Sorry for my brain fart reply. Something in my head said +ACI-75 ohms +AD0
COAX+ACI and I didn't read carefully.

Anyway, the main point is the same. If a transmission line sees an
impedance at each end equal to the characteristic impedance of
transmission line then the effects of changes in length will be minimal.

And here's some notes from the +ACI-Be Aware, But Don't Overthink This+ACI
department:

Do your radios have a 75 ohm antenna impedance? That will make a
difference to the transmission line.

Also, the height above ground is going to have an effect on both the
antenna's resonant frequency and impedance. There's some graphs on this
page, computed at 7.1 Mhz:

http://www.comportco.com/+AH4-w5alt/....php?pg+AD0-13

I expect you don't have many choices about where to put the antenna.
Higher is better than lower.

Getting the antenna out of the house and farther away from the electronic
noisemakers is the biggest deal here, everything else is small potatoes.