On 1 mar, 03:25, ka7niq wrote:
'Wimpie[_2_ Wrote:



;734551']On 28 feb, 20:53, Richard Clark wrote:-
On Sun, 27 Feb 2011 23:14:34 -0600, John - KD5YI
wrote:
-
Wimpie is right, Richard.-

I presume Wimpie can speak for himself. *As he offered musings that
were done on the back of a handy envelope, there is every chance he is
not right. *I offered a similar chance that I was not right either,
but I offered complete (two in fact) equations that no one has
disputed, and none have faulted for computation. *I admitted a
misapplication of one - which also passed without comment.

Considering Wimpie's work was not done for the antenna under
consideration (the size of his being much smaller where radiation
resistance varies by the FOURTH POWER of size) - what does "right"
mean?

73's
Richard Clark, KB7QHC-

Hello Richard,

you used r = 1m (as you have r in your formulas), that is D = 2m,
6.28m circumference.

I used D = 1.27m (4m perimeter), that is r = 0.635 m.

Quote from Norbert's site:
"When a magnetic loop antenna is used for 3.5 MHz with a perimeter of
4 meter *(13.3 foot) , it has an efficiency of approximately 3%."

Maybe this helps you to explain the difference between your and my
result,

Wim
PA3DJS
www.tetech.nl
Don't forget to remove abc in case of PM.

This has been a good thread, I have little room for an antenna, a mag
loop may be just the ticket for my small Tampa QTH ?

--
ka7niq

Hello Chris,

Which antenna will fit your needs depends on many factors (tuning
range, indoor/outdoor, aesthetics, local regulations, your experience/
preference, available volume, house construction, buy or homebrew,
available materials, local or DX use, etc). So I can't judge whether a
loop is good solution in your situation.

In addition, "the" best antenna for the transmitting case will very
likely not be the best one for the reception case.

Best regards,


Wim
PA3DJS
www.tetech.nl