All you need to do is use an insulated tower section, get the feed point
another 10' off the ground, and run (3) elevated radials. Now you have a
ground-plane, which works as well or better than a ground-mount
vertical. But not exactly yard or lawnmower friendly...
On 11/08/2013 05:55 PM, Rick - DJ0IP / NJ0IP wrote:
Let's not forget that we're talking about 1 6 0 meters here.
Of course 38 Ohms radiation resistance would be a great antenna but the
reality is, the vertical antennas most people deploy on that band are more
in the neighborhood of 10 Ohms (at best). The ground loss raises the
impedance high enough to fake the OM into believing he has a good antenna
because the SWR is not too bad.
It is not difficult to build an effective antenna on 160m when you have the
space for the radials, even if you can't go so high with the radiator. You
just need to use a lot of wire above the earth. Run the vertical section as
high as you can and then use 4 top-hat wires. Then you will have a great
signal, provided you have a decent radial network below the antenna.
Without tricks, in order to have 38 Ohms on a 160m vertical, it would have
to be 132 ft. high and have about 60 radials under it. I doubt that more
than 2 or 3 people here have ever had or even used something like that.
I sure haven't.
The bottom line is, if you don't have at least a half acre of land, you're
probably never going to have a big signal on 160m. With an acre, it's no
problem.
73
Rick, DJ0IP
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Stuart
Rohre
Sent: Friday, November 08, 2013 9:17 PM
To: tentec@contesting.com
Subject: Re: [TenTec] 160 M antenna
No one listening to the 38 ohm antenna will be able to tell the difference
in signal level from a 50 ohm antenna. There is way more variability in the
inonosphere than that small mis-match. Save your time for operating!!
Gud DX, try 10!
Stuart Rohre
K5KVH
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they usually imitate each other."
Eric Hoffer
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