Topband: topband: Tee Verticals
jimjarvis at verizon.net
Fri Oct 20 12:34:12 EDT 2006
For several years now I have used a 65' tall "Tee" vertical on 160. It is an
open wire fed 80 meter dipole with the feed point shorted and fed together.
This is fed against 6 or 7 elevated 1/4 wave radials. All of this is fed
through a homebrew Doug DeMaw "Ultimate Transmatch". I am very satisfied
with my signal on both bands as I am able to work anything I can hear.
However, I am willing to modify this system but want to see if anyone has
already done it before me.
What if I short the top hat at the 65' point and at attach just one side of
the open wire feeder. At this same point I will disconnect the other half of
the feed line thus creating an approximately 65' vertical radiator (closely
resonate to 80 meters. At the point of attachment of the elevated radials I
can add 6 or 7 additional elevated radials for 80 meters. Keep in mind I
will now have an 80 meter vertical about an inch away from my 160 vertical.
Do you think that by changing the current configuration I will lose
performance on either band, will it stay the same, or will it get better?
Thanks for your input
If I understand what you propose, you will change from a
dipole on 80m to a ground plane. I would expect the results on
that band to reflect reduced signal strength on signals within
about 1000 miles, possibly no change out to maybe 3,000 miles,
and improved performance on longer paths...on 80. If it were me,
I'd want to switch between dipole and vertical on that band.
Some nights into EU, horizontal is better.
On topband, the system would be unchanged, if I understand it
I had a dual band vertical, 80/160, using open wire line for the first 65',
and extending one side another 65', with 3 elevated radials for each band.
I wound up having to snip-tune the 80m side to make up for the velocity
factor of the OWL. Resonance was found around 62', rather than 65.
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