On Tue, 11 Jan 2005 07:55:19 -0500, "Glenn Ashmore"
wrote:

I understand that you are the resident authority on QFH antennas. Can you
help with this problem?

Hello Glenn,

I've had some experience with the QFH, Glenn, but I don't consider
myself an authority. However, I'll try to help you with the problem,
but first I'll need to know the form you used in your model. Is it
the self phasing type, with the inductive bifilar longer than the
capacitive one? Or are both bifilars of the same length and fed with a
power splitter and a 90° hybrid? If it is the self phasing type what
diameter is the tubing? And have you reviewed my data on the subject
that appears in Reflections?

If both the copper and stainless steel models are fabricated in
exactly the same form there shouldn't be much difference in
performance due the different materials. I don't believe the
difference in resistivities of the two materials should have a
significant effect on their performances, unless your bifilars are
made with very small diameter wire. If you used the self phasing type
the tubing diameter should be approximately 3/4", in which the
difference in resitivities would be absolutely insignificant.

So Glenn, give me the details of your QFH so that I can be of more
help.

Walt, W2DU