Circular of square shaped loop radiator ?
Using "loopcalc.exe", i compared the performance of a 10m circumference square shaped loop with a circular shaped loop.
A square shaped loop :
1. has only 5% (0,2dB) higher losses when used on 40m (1/4 lambda loop), unnoticeable difference.
2. has only max. 1.4dB higher losses when used as 80m (1/8 lambda loop), nearly unnoticeable difference.
3. is much cheaper and easier to construct.
My budget is very limited. As i have to get the best price / performance-ratio, i made my copper loop square shaped. With varying pipe diameters, the thickest copper pipe at the place with the highest currents running.