On Wed, 21 Dec 2005 17:14:37 -0800, dansawyeror
wrote:

Oh yes. The antenna is 5 to 7 and ground is 15.

Richard Clark wrote:
Did you include the 20 - 40 Ohms of Earth/Ohmic Loss in your Model?

Hi Dan,

Then it appears you are not measuring the radiation resistance + loss,
but rather its transform through the tuning of the
'large' screwdriver design

You might want to test your HP8405 against a 50Ohm load at the end of
the drive line, against known mismatched loads, and some measure of
the Q at each these nulls.

Do you choke the measurement drive line?

73's
Richard Clark, KB7QHC

Yes, I am measuring at the end of the cable. The 8405a is configured in a
balanced setup between a reference arm and an unknown arm. When the unknown arm,
i.e. the antenna is terminated in 50 Ohms the line length does not matter. That
was a surprise to me. The 8405a then reads the unknown at the end of the cable.

Richard Clark wrote:
On Wed, 21 Dec 2005 17:14:37 -0800, dansawyeror
wrote:


Oh yes. The antenna is 5 to 7 and ground is 15.

Richard Clark wrote:

Did you include the 20 - 40 Ohms of Earth/Ohmic Loss in your Model?


Hi Dan,

Then it appears you are not measuring the radiation resistance + loss,
but rather its transform through the tuning of the

'large' screwdriver design


You might want to test your HP8405 against a 50Ohm load at the end of
the drive line, against known mismatched loads, and some measure of
the Q at each these nulls.

Do you choke the measurement drive line?

73's
Richard Clark, KB7QHC