On 15 May 2007 20:17:18 -0700, dykesc wrote:

I'm not following your statement that the 4:1 appears to be mounted
backwards. While the 1:1 values are not exactly 4 times the 4:1
values, they are at least "ballpark". Just to make sure you understand
my arrangement, when measured, the 1:1 values should "ideally"
represent the line input impedance without transformation. The 4:1
values (line on the high impedance side of the balun, analyzer on the
low impedance side) should be down by roughly a factor of 4, right?

Hi Dykes,

Look at your data comparison again and ask: Should it be 4:1 or 1:4?

Also I'm not sure what you mean by my results luckily hitting the ham
bands. I cut and fed the antenna to accomplish that.

No doubt, as that is everyone's goal.

The OCF feedpoint
(at least by design) is just off the peak of a current loop on 80, 40
and 20 meters (even harmonics).

I'm not arguing results, I am arguing common sense. Moving the feed
along a dipole does not change its resonances and anti-resonances
(some prefer the terms series and parallel resonances); it changes
their impedances (I will ignore slight reactances). A balanced 80M
dipole resonates on 40M and 20M (and 10M, and 5M....) too. However,
the balanced dipole shows low resonance (series) and high
anti-resonance (parallel) impedances. You are showing consistent low
resonant impedances.

Well, in my review of all of your correspondence, you neglect to tell
us just how far off from center the feed is, and how much slope there
is to the overall wire, and even how long the wire is. I originally
offered that these peculiarities will induce oddities and caught grief
(well, not actually, perhaps it was more like guff) from Tom for
noting it.

However, I have worked out OCDs in the past in response to other's
discussion and there are a world of results and I am going to attempt
to read tea leaves here to intuit the missing details:

The feed is roughly 15% to 20% from the end and there should be almost
as good a match somewhere between the 25M and 30M band. A flat OCD
will show a much poorer match in the 80M band (it will resonate
there), but sloping may introduce enough variation to pull it in
(where the ground is soaking up some of your power as sort of a Z
pad).

At 25% from the end, and there should be no 20M operation as you
describe.

There are possibilities at 35% to 40%.

Let me know about matches inbetween 40M and 20M.

73's
Richard Clark, KB7QHC