On Thu, 22 Jan 2009 10:19:14 -0000, "christofire"
wrote:


"Richard Clark" wrote in message
.. .
On Thu, 22 Jan 2009 01:06:28 -0000, "christofire"
wrote:

With a pair of screened loops and a whip it is possible to receive
separately the magnetic and electric fields associated with a radio signal
and to record their strengths at different locations. This can reveal
significant differences on account of building and electrical clutter, but
only if the loop is adequately screened. No myth!

What you describe is a direction finding system with a general antenna
that can be switched in to sniff for a transmitter to take a bearing
on. A commonplace design for this application.

No, the loops were commutated in order to provide an omni-direction pattern
in the horizontal plane and the receiver was switched between the loops and
whip to measure H and E. This was used to establish for medium and
long-wave broadcasting stations (in the UK) the field strength and
receivability on ferrite-rod antennas.

The description you offer in rebuttal says nothing of field
separation. The commutation discussion imparts nothing to the
physical relationship of the wave. The remainder of the description
doesn't actually describe any physical/geometric relationship to the
wave at all. Physics in the UK are not different from the rest of the
world.

The loops are no more
screened than any other, and careful observation of their construction
details would reveal the necessary break in the screen which serves
for balance only.

The loop has to be split at some point to prevent it acting as a shorted
turn - the splits were at the top in this case.

This, too, is merely conventional design then.

You haven't described anything out of the ordinary, and the ordinary
(spanning centuries) has not shown the attributes you describe as
field separation.

You're entitled to your opinion.

As are you, but this isn't rec.radio.amateur.antenna.polls and you
haven't gone beyond unsubstantiated claims.

If the necessity of proof for your claims were set aside, Nature still
demands that noise and signal still arrive by the same mechanism and
any invention that separates fields must apply them equally to both
sources - returning us to the conventional observation that S/N hasn't
changed one bit. The net result of this is that you have provided
unsubstantiated claims for an useless invention. Any value it may
have comes by conventional means.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Thu, 22 Jan 2009 10:19:14 -0000, "christofire"
wrote:

"Richard Clark" wrote in message
...
On Thu, 22 Jan 2009 01:06:28 -0000, "christofire"
wrote:

With a pair of screened loops and a whip it is possible to receive
separately the magnetic and electric fields associated with a radio signal
and to record their strengths at different locations. This can reveal
significant differences on account of building and electrical clutter, but
only if the loop is adequately screened. No myth!
What you describe is a direction finding system with a general antenna
that can be switched in to sniff for a transmitter to take a bearing
on. A commonplace design for this application.
No, the loops were commutated in order to provide an omni-direction pattern
in the horizontal plane and the receiver was switched between the loops and
whip to measure H and E. This was used to establish for medium and
long-wave broadcasting stations (in the UK) the field strength and
receivability on ferrite-rod antennas.

The description you offer in rebuttal says nothing of field
separation. The commutation discussion imparts nothing to the
physical relationship of the wave. The remainder of the description
doesn't actually describe any physical/geometric relationship to the
wave at all. Physics in the UK are not different from the rest of the
world.

The loops are no more
screened than any other, and careful observation of their construction
details would reveal the necessary break in the screen which serves
for balance only.
The loop has to be split at some point to prevent it acting as a shorted
turn - the splits were at the top in this case.

This, too, is merely conventional design then.

You haven't described anything out of the ordinary, and the ordinary
(spanning centuries) has not shown the attributes you describe as
field separation.

You're entitled to your opinion.

As are you, but this isn't rec.radio.amateur.antenna.polls and you
haven't gone beyond unsubstantiated claims.

If the necessity of proof for your claims were set aside, Nature still
demands that noise and signal still arrive by the same mechanism and
any invention that separates fields must apply them equally to both
sources - returning us to the conventional observation that S/N hasn't
changed one bit. The net result of this is that you have provided
unsubstantiated claims for an useless invention. Any value it may
have comes by conventional means.

73's
Richard Clark, KB7QHC

Hi Richard,

Are your powers of perception waning by any chance? Your correspondent
deserves more credit than you're allowing him. As far as I've seen in
this thread, you're the only one talking about 'field delamination' or
such things. As you said, what he is talking about is purely
conventional. And clever. That you apparently don't completely
understand what he is saying is no fault of his.

73, ac6xg

On Thu, 22 Jan 2009 11:18:03 -0800, Jim Kelley
wrote:

Are your powers of perception waning by any chance? Your correspondent
deserves more credit than you're allowing him. As far as I've seen in
this thread, you're the only one talking about 'field delamination' or
such things.

Perhaps you powers of perception did not perceive this:
On Thu, 22 Jan 2009 01:06:28 -0000, "christofire" wrote:

With a pair of screened loops and a whip it is possible to receive
separately the magnetic and electric fields associated with a radio signal

Returning to your complaint:
That you apparently don't completely
understand what he is saying is no fault of his.

As christofire's quote above is his and not mine, and neither you nor
he has explained it, my comprehension is not tested beyond what his
unconventional statement has offered. If he cannot explain it, then
the fault is not with me. Challenging blank assertions is not unusual
here.

Perhaps you mis-perceived:
On Thu, 22 Jan 2009 01:06:28 -0000, "christofire" wrote:

The way I look at it, there is no such thing as a "magnetic" antenna.
because, in fact due to christofire's poor quotation practice, this
statement is Mark's and one that I fully concur with and stated so.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Thu, 22 Jan 2009 11:18:03 -0800, Jim Kelley
wrote:

Are your powers of perception waning by any chance? Your correspondent
deserves more credit than you're allowing him. As far as I've seen in
this thread, you're the only one talking about 'field delamination' or
such things.

Perhaps you powers of perception did not perceive this:
On Thu, 22 Jan 2009 01:06:28 -0000, "christofire" wrote:

With a pair of screened loops and a whip it is possible to receive
separately the magnetic and electric fields associated with a radio signal

I perceive that the quote says nothing about "field separation" -
whatever that is. Since it's a term that you employed, perhaps you can
explain what you mean by it and clear up the whole thing.

Thanks,

ac6xg

On Thu, 22 Jan 2009 13:43:19 -0800, Jim Kelley
wrote:

separately the magnetic and electric fields associated with a radio signal

I perceive that the quote says nothing about "field separation" -

Now that is getting "précis."

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Thu, 22 Jan 2009 13:43:19 -0800, Jim Kelley
wrote:

separately the magnetic and electric fields associated with a radio signal
I perceive that the quote says nothing about "field separation" -

Now that is getting "précis."

73's
Richard Clark, KB7QHC

c'est exact

Do you claim to have separated voltage from current whenever you measure
one or both?

ac6xg

"Jim Kelley" wrote in message
...
Richard Clark wrote:
On Thu, 22 Jan 2009 13:43:19 -0800, Jim Kelley
wrote:

separately the magnetic and electric fields associated with a radio
signal
I perceive that the quote says nothing about "field separation" -

Now that is getting "précis."

73's
Richard Clark, KB7QHC

c'est exact

Do you claim to have separated voltage from current whenever you measure
one or both?

ac6xg


Isn't the point that an electromagnetic wave can be considered in terms of
the E or H fields associated with it, or indeed both at the same time? If
any power is extracted from the wave then this will involve E and H, or
voltage and current, simultaneously. And when the wave encounters a region
of space with effective relative permittivity or permeability different from
the free-space values, the ratio of E to H changes; that is, the intrinsic
impedance, Zo changes locally. The work I described earlier contributed to
the development of propagation prediction methods for medium and long wave
transmissions and an example of a region of space that exhibits a
particularly inductive effect is a built-up city with many tall buildings.

I'm aware of issues involved in claiming generation of separate E or H
fields, as has been described by Kabbary et al in their 'crossed-field
antenna', but surely the issues concerning a receiving antenna are
different? A very short monopole attached to a high-input-impedance
amplifier, for example (i.e. an 'active' antenna), should have very little
effect on the local intrinsic impedance, yet it should produce a signal
proportional to the magnitude and sign of the local E field, whatever the
local H field strength. Equally, a small-diameter well-screened loop should
be capable of measuring the local H-field strength without altering the
local Zo. In these cases, 'short' and 'small' are relative to the
wavelength.

Rohde & Schwarz used to sell an HF diversity receiving antenna system based
on an array of small screened loops, the screens of which were applied
(separately) as active monopoles. This provided somewhat separate reception
of the E and H fields associated with the incoming radio wave and, from what
I've heard, it worked - it provided some degree of 'diversity gain'.
However, this was an array requiring a sizeable amount of clear land.

Perhaps the difference is that what I described before was for use with
broadcast signals (following the topic of the OP), in which case short and
small antennas can be used for measurement purposes within areas provided
with adequate (or nearly adequate) field strength, whereas in amateur radio
applications the tendency would be to use as large an antenna as possible,
to maximise the possible range.

Chris