[Antennas] Feeding a loop

[Michael Josefsson]

Normally a loop has an impedance of about 120-130 ohms resistive if  
the loop is at resonance. This opens for the possibility of quarter- 
wave-matching: Use a quarter-wavelength 75 ohm coax (taking care of  
the used coax's velocity correction factor) nearest the antenna. At  
the end of the coax you will see about 50 ohm and you can continue  
from there with normal 50 ohm coax with no problems. So given that you  
can find coax of suitable color you will be just fine.

/Micke
On 3 jul 2008, at 04.18, Jim Miller wrote:

> I want to put up a 40 meter and maybe an 80 meter loop if it turns  
> out it will fit.  OK, I know I should feed it with window line but -  
> that will make it too visible and bring the wrath of neighbors.  I  
> currently have a Butternut vertical behind a tree but it is in a  
> ditch and I want the height I can get with the loop.
>
> I could drop a piece of ladder line to or near the ground and then  
> take coax on the ground to the shack.  Will I still be able to use  
> this on multiple bands as if I was running ladder line all the way  
> to the tuner?  Something kike a G5RV does.  I don't want to be  
> limited on power so I do not want to put a tuner at the antenna.
>
> Thanks es 73, de Jim KG0KP
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