[Lowfer] Loop Antennas for Transmitting

[Bill Ashlock]

Les,

I can show you numerous text books that say "the transmitting loop has 
little practical for transmitting". I can also find numerous reports of poor 
performance for the TX loop at any frequency. I have also seen numerous 
reports of excellent performance for TX loops. I don't believe the truth is 
halfway between but a matter understanding how to use them.

At 185k the radiation resistance is about 100 times lower compared to a 
vertical of equal size, and this is a bad characteristic. So the current in 
the loop has to be 10 times higher to make up for this....  and this is 
doable if you understand how to deal with the variables..... and they are 
quite different than those for a vertical. In fact the loop is far less 
susceptible to outside forces and is much easier to install.  .....and far 
less unsightly, if not invisible.

My next loop article attempts to explain in detail how to set up an 
effective TX loop from A-Z. Right now I'm stuck on trying to mathematically 
explain how I can be measuring more far field radiation than I should, per 
the std radiation resistance equations!

Bill

>Not to open a can of worms, but could we discuss transmitting loops
>in general terms?
>
>Based on their use on the 160 meter band, they seem to be poor
>performers as compared to short wavelength verticals. Lots of antenna
>current, but poor radiation.
>
>Can someone explain to the village idiot (me) why they would perform
>any better on LF, than they seem to on the MF bands? My understanding
>is that Bill's design is basically a single turn vertical loop that is 
>tuned to
>resonance, correct? I'm assuming something like 50 foot in circumference?
>
>73,
>
>Les Rayburn, N1LF
>
>
>Les Rayburn, director
>High Noon Films
>100 Centerview Drive
>Suite 111
>Birmingham, AL 35216
>(205) 824-8930
>(205) 824-8960 FAX
>(205) 253-4867 CELL
>
>
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