Subject: Re: [FG]:

From: jerry volland <[email-masked]>
Date: Sat, 12 Mar 2005 09:37:05 -0800 (PST)

Hi, Charlie.
 
Thanks for the note.  I've been offline so long I forgot the correct syntax.  Here's the link:
http://www.freewebs.com/attatchments/artifacts/artifacts.htm

Charles Ford <[email-masked]> wrote:

--- jerry volland wrote:
> http://www.freewebs.com/attatchments/artifacts.htm

Not found

Charles Ford
KC5-OWZ
[email-masked]
[email-masked] 

To be absolutely sure you make it past the "SpamGuard" you can simply include my ham-radio callsign (above) somewhere in the message body. I have a filter set.

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---

From: "M J Mitch Mitchell" <[email-masked]>
Date: Sat, 12 Mar 2005 10:18:37 -0800

worked for me

Not found

Charles Ford
KC5-OWZ
[email-masked]
[email-masked]

To be absolutely sure you make it past the "SpamGuard" you can simply 
include my ham-radio callsign (above) somewhere in the message body. I have 
a filter set.

---

From: David Dameron <[email-masked]>
Date: Wed, 16 Mar 2005 23:32:41

There has been discussion of what effects there would be in a transformer
if it became large compared to a wavelength.

Normally one does not think of propagation delays in a transformer, but
things like the change of magnetic flux, etc. However usually transformers
are very small compared to a wavelength. If one was built "large", would it
turn into an antenna, or is the "transformer" induction somehow different
than "near field" antenna theory?

Well I attempted to try it out, strung a horiz. rectangular loop in my rear
yard and fed it with a 6MHz signal from a small transmitter. In the center
was a small pickup coil or secondary that could be moved in position. I
attempted to measure a phase shift (in addition to that from the coax
cables). The large loop was about 30 feet on a side, about 9 meters, so the
4.5 meters to the center is about 33 deg. phase shift.
(wavelength = 50 m). It turns out difficult to measure the phase shift with
my scope (AC line wires and possibly the ground are affecting measurements,
but it appears small.

I also want to simulate it, does anyone know some simulations to calculate
the current along the loop, that is deviations from constant current?
I found this link:
http://www.ee.surrey.ac.uk/Personal/D.Jefferies/loop.html

Alternatively, is there an easy way to measure the current along the large
loop wire, say some sort of loop field-strength meter?
Once I have a current distribution, I can easily calculate the B-Field and
flux linking the receive loop, and compare to the signal I get.
Thanks,
Dave D.