On 8/4/2018 5:53 PM, Mikek wrote:
A good reference for Beverage antenna length is by W3LPL, Search
online for his patterns, F/B info.
If a shorter Beverage wire length is used because of space
restrictions, a near perfect feed and restive termination can
appear as a low VSWR, over a reasonable frequency range.
However here in Maine, the ground is typically not close to level
in elevation , and with variations in soil conductivity, resonant
lengths are beneficial..
One of the ways to make a wire look electrically longer is the use of
covered wire. (Velocity factor that can vary with type of covering used).
Also some have placed small lumped inducatances along the way,,
Another used a slinky..
Basic understanding about cores that most, excepting mix 33, are
inductive, So have a question for anyone who has tried it.
Will adding many mix, 43, and 77 spaced cores with a few turns
each along the Beverage wire , lower the basic frequency enough to
be beneficial?
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I recently added 9 binocular cores (Fairrite # 2873000202) to my
253ft BOG.
Before the Cores my velocity factor was .78
After installing the cores the VF was .67
So, I'm thinking it made my antenna seem to be 16% longer, or went
from and apparent 324ft to 377ft.
I was shooting for .55 and will add more cores when I get them.
Even the the cores are binocular, I only made a single pass through
one hole of the core.
That equals about 8.9uh.
You probably have this URL, it is the only info I can find.
https://www.w8ji.com/slinky_and_loaded_beverages.htm
Mike Knowlton
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