Towertalk
[Top] [All Lists]

Re: [TowerTalk] new Steppir antenna

To: "Jim Lux" <jimlux@earthlink.net>
Subject: Re: [TowerTalk] new Steppir antenna
From: "Rick Karlquist" <richard@karlquist.com>
Reply-to: richard@karlquist.com
Date: Tue, 5 Oct 2004 14:55:08 -0700 (PDT)
List-post: <mailto:towertalk@contesting.com>
Jim Lux said:
, the SteppIR looks like a dipole with a 10-20 pF
> capacitor
> across the feedpoint?  In the usual scheme of things, I assume that you
> just make the elements a bit different length to tune out the C.
>
> Then, if you're attempting to go down to 3.5 MHz, the loading L interacts
> with the C, which superficially, you could tune out (make the L a bit
> bigger), but then, because the Q is high, you're going to have big
> currents
> and voltages in the LC combination?

I wanted to modify a 2 element SteppIR Yagi (the regular one)
for 30 meters (as a dipole).  Since I would be running only 100 watts, the
voltage was "only" a coupla thousand volts.  The scheme might
have been workable (not easy but workable) if it weren't for
the 25 pF of shunt capacitance.  With a couple of thousand
volts across this "capacitor", the "dielectric" would probably
be toast.

I elected to put up a 30 meter vertical instead.

Rick N6RK

_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>