In message , Reg
Edwards writes
Trev,

As Cecil says, a wider than expected bandwidth in an antenna of given
size, is an absolutely sure sign of greater loss somewhere in the
wideband antenna system.

Unless one knows how the thing is supposed to work, which with EH and
CFA is not very likely, there's no indication of where the loss may be
except from a visual examination. If there are any coils of
relatively thin wire, either in the antenna or tuner/phaser, then
that's a good pointer.

But experimenting to improve the bandwidth*efficiency product, one way
or the other, will not get you very far. As one goes up the other is
sure to go down. It's not difficult to guess which you would prefer.

A magloop. with a single turn coil of copper pipe at the lower
frequencies, is far and away the most narrow banded and therefore the
most efficient of all the small antennas. Furthermore it has a
built-in, equally very low loss tuner.
----
Reg.

Thanks for your time Reg,
I drafted a lengthy response to your note above a little earlier but
binned it in favour of this :-) I suppose my problem is that I would
dearly like to believe the claims for the EH et al but my head tells me
that it can't be so. I have had a lot of fun 'playing' with the idea and
I suppose I should be happy with that.

Trev

--
Trevor Day
UKSMG #217
www.uksmg.org

Richard Fry wrote:

"Reg Edwards"
As Cecil says, a wider than expected bandwidth in an antenna of given
size, is an absolutely sure sign of greater loss somewhere in the
wideband antenna system.

I don't know your definition of an "expected bandwidth," but for a
reality check--many forms of panel antennas used in FM and TV broadcast
transmission have 20% or better SWR bandwidth, and radiate nearly every
watt that can be delivered by the feedline with almost NO "matching"
losses. They have been in routine use for decades at master antenna
transmit sites all over the world.

And, for the record, it wasn't me who said that.
--
73, Cecil http://www.qsl.net/w5dxp


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So ?

Frank wrote:

"Spike" wrote in message
.. .
Frank wrote:

The spring and damper can be exactly model as an electrical analog;

I'm sure you're right.

However, a coil/capacitor is not a model or analogue of a
spring/damper system. It was discussed extensively at the time.


I am not sure I understand your response. To be exact a "spring/damper" can
be modeled as a coil/resistor.

I refer you my other post on the subject, where I quote the OP in
full.

For resonance to occur you need a
capacitor/inductor, or mass/spring. All components of either mechanical or
electrical circuits require the solution of the same simple differential
equation, such as i = C*dv/dt etc.

No-one was arguing that that was not the case. A spring might have the
mechanical equivalent of reactance, but a damper will most certainly
not - hence the rubbish posted by the OP, where he believes that
dampers store energy. They do not, and therefore cannot have the
mechanical equivalence of a reactance. Therefore, resonance is not
possible with such a system. In the extreme, the OP was reduced to
likening dampers to bicycle pumps, a sure sign of a failure to grasp a
fundamental point (and hence the error of his assertion).

from
Aero Spike

Richard Fry wrote:

I don't know your definition of an "expected bandwidth," but for a
reality check--many forms of panel antennas used in FM and TV broadcast
transmission have 20% or better SWR bandwidth, and radiate nearly every
watt that can be delivered by the feedline with almost NO "matching"
losses. They have been in routine use for decades at master antenna
transmit sites all over the world.

Now shrink down those antennas by a factor of, say, 10 in size. Think
they'd still do it? If so, you're the natural prey for the charlatans.

In product development, we say fast-cheap-good, pick any two. With
antennas it's small-efficient-broadband, pick any two. "Small" is, of
course, always in terms of wavelength when it comes to antennas.

Roy Lewallen, W7EL

"Richard Fry" wrote in message
...
"Reg Edwards"
As Cecil says, a wider than expected bandwidth in an antenna of
given
size, is an absolutely sure sign of greater loss somewhere in the
wideband antenna system.
________________

I don't know your definition of an "expected bandwidth," but for a
reality
check--many forms of panel antennas used in FM and TV broadcast
transmission
have 20% or better SWR bandwidth, and radiate nearly every watt that
can be
delivered by the feedline with almost NO "matching" losses. They
have been
in routine use for decades at master antenna transmit sites all over
the
world.

RF
==================================

I've no reason to doubt it.

But this is a topic about the bandwidth of physically small HF
antennas.

And as usual, when the slightest difference of opinion occurs,
somebody invariably feels impelled to go off at a tangent and drag in
something they feel more at home with, such as VHF and UHF TV
transmitting antennas, and, very soon, if we are not careful,
distractions such as scattering parameters, reflected power, etc.
----
Reg

"Roy Lewallen" wrote -
Now shrink down those antennas by a factor of, say, 10 in size.
Think
they'd still do it? If so, you're the natural prey for the
charlatans.

===============================

Roy, I'm thinking of occasionally changing 'old wives' to
'charlatans'. It may sometimes better fit the circumstances.
----
Reg.

"Cecil Moore" said,

And, for the record, it wasn't me who said that.
===================================

As it was quite true you just as well could have said it. So I didn't
take the trouble to correct the minor error.

Sorry Roy.
===
Reg.

Ever heard of a diversity receiver?

==============================

You seem to enjoy starting useless arguments.
Are you a troll?
Spacial or frequency diversity?
Leave me out of it.
---
Reg.

For resonance to occur you need a
capacitor/inductor, or mass/spring. All components of either mechanical
or
electrical circuits require the solution of the same simple differential
equation, such as i = C*dv/dt etc.

No-one was arguing that that was not the case. A spring might have the
mechanical equivalent of reactance, but a damper will most certainly
not - hence the rubbish posted by the OP, where he believes that
dampers store energy. They do not, and therefore cannot have the
mechanical equivalence of a reactance. Therefore, resonance is not
possible with such a system. In the extreme, the OP was reduced to
likening dampers to bicycle pumps, a sure sign of a failure to grasp a
fundamental point (and hence the error of his assertion).

from
Aero Spike

I am not aware of a damper ever being considered a storage device.
Capacitance is equivalent to mass, Inductance is equivalent to a spring, and
resistance equivalent to a damper. Am I missing something?

Anyway will read later posts and see what I can get out of it.

Frank