The impedance of an antenna in the real world is not 50 ohms resistive,
which is what the meter is telling you when you attach the "calibrated"
termination resistor.
Impedance is a complex unit, consisting of resistive and reactive
components. Rather than write an off-topic book here, I suggest you read
the Antenna Handbook - or, if all else fails, the Autek instruction manual.
Al - K8EUR
----- Original Message -----
From: "Dan Sawyer" <dansawyer@earthlink.net>
To: "amps" <amps@contesting.com>
Sent: Saturday, February 26, 2005 4:16 PM
Subject: [Amps] close to off topic - how to read antenna R + jX ??
> All,
>
> I have become interested in leaning more about what is actually going on
> at the antenna. I have a vertical and would like to measure it.
>
> First I have an Autek RF-1. It measures swr, Z, L, and C at a preset f.
> I am not certain what the L and C are reading. When I measure a 50 Ohm
> terminator at 7.2 MHz it actually reads a Z of 50 and an SWR of 1.0.
> However the L and C readings are of 2 uH and 2500 pf. What are these
> actually measuring? The values are very close to those from the antenna.
>
> How can I actually measure the L and or C component of the antenna? If I
> use an impedance bridge at the frequency will it measure L (or C)?
>
> I hope this is close enough to topic.
>
> Dan
>
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>
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