On Wed, 4 Nov 2015 00:17:11 -0500, rickman wrote:
On 11/2/2015 7:39 PM, Jeff Liebermann wrote:
On Mon, 2 Nov 2015 09:13:38 -0600, amdx wrote:
Below some pressure level, it will probably flop over if mounted
vertically. That's why I mumbled that I wasn't sure if it should be
mounted vertically with a support pole, or horizontally on a flat
sheet of plywood. Both will work, but I'm not sure which is better.
Hang it upside down.
Mikek
But, all the photons will fall out of the loop that way.
Actually, there's a problem. It doesn't work as well upside down.
The magnetic loop has a rather directional field and takeoff angle and
does NOT have a constant current around the loop:
http://www.nonstopsystems.com/radio/vids-ant/antenna-Mag-Loop-Demo1.wmv
I don't get this video. I can't really hear what he is saying so when
he says at the end, "this is not what you would expect" I don't get it.
I had the same problem. I would guess(tm) that what he's mumbling is
that one would expect the current to be constant around all parts of
the loop, yet it displays obvious maxima and minima.
https://www.youtube.com/watch?v=SUYI81dkEMA
This video is about the voltage and current around a loop, but he says
it is a 1/10 wave loop, but I can't tell that. He has another video
showing the directionality of a 1/4 wave delta antenna. I'm wondering
if this is also a 1/4 wave antenna.
At 6:30 in the above video, he proclaims that it's a 1/4 wave loop.
At 6:42, the MFJ-259B shows 29.555 MHz on the display. I couldn't
find where he said it was a 1/10 wave loop. 1/10 wave is the
defacto definition of a "small" loop.
I suspect that an inverted loop will send most of the RF into the
ground. I should probably test this.
http://www.nonstopsystems.com/radio/img-ant/antenna-magloop-rad-angle.gif
Which type of loop antenna are you talking about, 1/4 wave, or 1/10
wave (small, magnetic)? I can't tell anything about this antenna and it
seems to contradict the other video.
I'm not saying anything about the drawing except that it shows that
the loop might be somewhat directional, which might be a problem.
Where's the contradiction?
http://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm
Gone...(again).
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558