On 5/25/2013 1:48 AM, David Ryeburn wrote:
In article , John S
wrote:

If you ran the analysis with the loop closed on those two bands, would
you mind doing it over with the loop open?

7.05MHz 117.3 - J 0.2996 ohms closed loop
3.525MHz 9.365 + J 111.4 ohms open loop
10.125MHz 253.9 + J 60.16 ohms open loop


Those are free-space values. I forgot to put the ground in. Here they
are revised for the bottom to be about 1.3m above ground...

7.05MHz 123.6 - J 0.02019 ohms closed loop
3.525MHz 13.57 + J 105.7 ohms open loop
10.125MHz 261.7 + J 14.89 ohms open loop

And for completeness:

14.05MHz 265.2 + J 78.03 ohms closed loop
21.15MHz 181.4 + J 286.6 ohms closed loop
28.05MHz 322.6 + J 397.5 ohms closed loop


Many thanks. That confirms what I thought, except that I had expected
the antenna to be on the capacitive side of resonance on 30 metres. All
the figures indicate that my 142.7 ft loop is just a bit too long.

Well, I didn't know your wanted to see the results with a 142.7 ft loop.
I thought you wanted to start with it resonant at 7.05MHz and let the
other figures fall where they may. Here it is repeated for 142.7ft.

3.525MHz 12.41 + J 59.12 ohms open
7.05MHz 116.3 - J 83.72 ohms closed
10.125MHz 244.3 - J 82.4 ohms open
14.05MHz 212.9 - J 78.4 ohms closed
21.15MHz 112 + J 33.87 ohms closed
28.05MHz 258 + J 77.07 ohms closed