Topbanders,
thanks for all the valuable input.
So far i can say the beverage was of great help in the past 160m contest
although it still is not optimized. At DL0WH, we didn't work much, we
rather tested the performance. Conclusion was: NW works great, SE
..uhm.. not.
The K9AY loop
done.
73, John W1FV
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Martin
Sent: Wednesday, January 24, 2018 6:28 AM
To: topBand List
Subject: Topband: How to determine impedance
Topbanders,
for the construction of the beverage ( a 2 wire reversible bevera
esting.com] On Behalf Of Martin
Sent: Wednesday, January 24, 2018 6:28 AM
To: topBand List
Subject: Topband: How to determine impedance
Topbanders,
for the construction of the beverage ( a 2 wire reversible beverage, that
is) from my post a few days ago i wanted to know how to measure or
Another line Z measurement technique is with a scope and reasonably fast
risetime (few nsec) pulse generator. Terminate about a 20' length of
line with a variable non-inductive pot or carbon comp resistor selection
and drive a pulse at the other end and adjust the resistance for minimum
Hello Martin,
I have other equations here:
www.w0btu.com/bev_ant_impedance-math.html
Other charts, matching transformer ratios, etc. are on
www.w0btu.com/Beverage_antennas.html
73, Mike
www.w0btu.com
On Wed, Jan 24, 2018 at 5:27 AM, Martin wrote:
> Topbanders,
> for the
Am 26.01.2018 um 02:42 schrieb Richard (Rick) Karlquist:
You don't need to divide by length.
You are darn right. I just verified it.
I found Zo=sqrt(L/C) on a forum and thought this can't be right because
coax like rg58 has C about 100 pF PER METER. So i modified the formula,
verified it
On 1/24/2018 3:27 AM, Martin wrote:
With both ends open, measure capacitance C of DUT, divide it by it's
length ( C' = C/m) .
Shorten one end, measure inductance of DUT, divide it by length ( L' =
L/m) .
Now calculate
Z= 1000 * squareroot(L'/C')
You don't need to divide by length.
Topbanders,
for the construction of the beverage ( a 2 wire reversible beverage,
that is) from my post a few days ago i wanted to know how to measure or
determine the impedance of the open wire. I stumbled across a very
simple method some of of you might know , some might not. Anyway, here
is