On Tue, 9 Nov 2010 01:48:16 -0800 (PST), spamhog
wrote:

Have I been googling for the wrong things?

None of these issues seriously impacts the simplicity of your initial
request, but your elaborations of anticipating grief are numerous.

What do you REALLY want?

73's
Richard Clark, KB7QHC

What do you REALLY want?

73's
Richard Clark, KB7QHC

Dear Richard,

My question is very simple:

I'd cut a dipole of about 15 + 15 m (50+50 ft), 120 deg. inverted V,
apex at 15 m.
I could do 1:4 - 300 ohm or 1:9 - 625 ohm.
What would be the least-bad?

If you can't or won't tell if such an antenna very roughly better
matches a 300 or 600+ ohm source over the HF spectrum,, what else
can I do but
- turn on EZNEC and start playing
- build two or more transformers and send someone up at the 50ft apex
and swap them in sequence while I do in vivo comparisons and pollute
the spectrum
- wait for someone else to answer or to point me to a good URI?

I can live with it.

I might also put together the rather long list of authors of articles
on the subject and ask them on your behalf what they really really
want if they have to feed the thing with a coax instead of ladder
lines of the commercially available impedances and want the least
lossy solution among the available alternatives. :-)

73 es tnx de n1jpr/i2

On Wed, 10 Nov 2010 04:33:31 -0800 (PST), spamhog
wrote:

What do you REALLY want?

73's
Richard Clark, KB7QHC

Dear Richard,

My question is very simple:

I'd cut a dipole of about 15 + 15 m (50+50 ft), 120 deg. inverted V,
apex at 15 m.
I could do 1:4 - 300 ohm or 1:9 - 625 ohm.
What would be the least-bad?

If you can't or won't tell if such an antenna very roughly better
matches a 300 or 600+ ohm source over the HF spectrum,, what else
can I do but
- turn on EZNEC and start playing

You keep repeating what you have. Can't or won't telling is still a
matter of

What do you really want?

You are forcing this into my trying to read between the lines and
guessing, so here goes:

- in spite of demurring about
no pretense to have perfect match
or minimum losses.
You "want" something with a near-perfect match and near-minimum losses
"over the HF spectrum."

This is dreaming in technicolor and 5.1 Dolby sound.

This is a technical forum and the expectation is that you provide a
range of acceptable match and a range of acceptable loss enumerated by
the frequencies of interest. You show no concern for directionality
which will be wildly variable. In other words, something quantifiable
is needed or you are doomed to inaccurate response or tedious
instruction (such as mine). Qualified statements are suited only for
cheap sales brochures.

To your credit, you enumerate the particulars of your antenna and to
some extent the working band: 3MHz to 30MHz. However, even on first
glance, such an antenna is NOT suited for covering the entire HF
region. This should have been a minimum observation in your readings,
and the absence of its discussion by you means you either have poor
sources, or you are prepared to abandon this antenna's use on some
bands (do your sources tell you were it is going to fail miserably?).
The use of BalUns is not a solution to this and the solution, such as
it is with a Hi-Z resonator, forces problems into the other bands.
This too should be a minimum observation available from your reading
material.

I might also put together the rather long list of authors of articles
on the subject and ask them on your behalf what they really really
want if they have to feed the thing with a coax instead of ladder
lines of the commercially available impedances and want the least
lossy solution among the available alternatives. :-)

Try googling the terms "wide band" "hf antenna" and writing to the
2,960 authors.

This board is innundated with claims and testimonials to those designs
all the time - such freely available "articles" do not constitute
evidence nor bring legitimacy.

There is one very simple, logical test for the answer to your unstated
question - if you can't buy or find one, why do you think it exists or
can be so easily assembled?

73's
Richard Clark, KB7QHC