On Sat, 23 Feb 2008 12:00:13 -0500, aa4nc@aol.com wrote:
>I'd be interested from hearing from anyone who has had good luck
>mounting a 160m inverted L on standoffs from a grounded steel
>tower.
Since you have two towers, you can easily hang a top-loaded Tee,
which is even better than an inverted L, because it has relatively
little high angle radiation. I've used one for several years, and
it is a VERY effective antenna. The more radials the better, of
course, to improve the efficiency. It's a VERY simple antenna --
vertical section as tall as you can get it, then tie wires to top
in opposite directions that are long enough to bring it to
resonance (or get it close enough that your tuner can handle it).
Even better, take it past resonance (longer) and add series
capacitance to tune out the inductance. This results in a better
match to your coax.
If the two supports are too close together to get enough length
into the vertical section, you can get more top loading with a
pair of wires at 90 degrees coming down like an inverted vee from
that top point. The top loading is essentially capacitance.
Now, folks will tell you that you WANT the high angle radiation
from the top of the L. I strongly disagree. No one within several
hundred miles has ever complained about my Tee not being loud
enough, and that's where that upward stuff would matter.
73,
Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|