[Elecraft] magnetic loop antennas

[Roger Quayle]

Hi

I live in an apartment (temporary) and built a 36" diameter magnetic loop
with a vacuum variable capacitor bought off eBay, tuned by a motor drive.
It is optimized for 20 and 17 meters, but works well on all bands from 40 to
10 meters (this really depends on the capacitance range)

It tunes to a low SWR on my KX3 and works very well outside, clear of the
building.  But on the apartment balcony the performance is poor, as it is
too close to rebar in the concrete framing and the steel mesh in the stucco
walls

Roger
NZ6RQ / ZL2BHW


-----Original Message-----
From: Bill Blomgren [mailto:billblom at nc.rr.com] 
Sent: Monday, May 20, 2013 6:43 PM
To: elecraft at mailman.qth.net
Subject: [Elecraft] magnetic loop antennas

I saw the great writeup on the magnetic loop antenna and the inventive High
Voltage capacitor for tuning the thing.  I'm looking at one of them strictly
because I'm stuck in an apartment.

The fact it should be good for 100 watts is perfect for what I'm looking at
buying.

I'm just wondering about the copper pipe used for the outer loop... I
spotted some very reasonably priced flexible conduit that could be used for
the "loop" proper.  Do what is necessary to bond the capacitor into the rig,
and it would appear to be a reasonable alternative to the rather pricy
copper pipe. (They want your first born here for that, and the thieves are
busy collecting anything that isn't nailed down.

Thoughts on that for its larger diameter, which should help with the
coupling to the rest of the world...