[Lowfer] loop performance

[Bill Ashlock]

>Which brings up an interesting point...perhaps my RG-11 loop outperforms 
>your RG-8 loop because >mine is in a diamond configuration (one high 
>support) with no sides parallel to earth rather than >the mil-spec braid 
>being  superior as hypothesized earlier...or maybe a combination thereof.

Yeah, a I suppose a good test of the diamond vs the square might be worth 
while. One problem with the typical diamond (plane of the square rotated 
45deg) is that apex at the top has to be 1.4x higher than the normal square 
and this brings in the question of legality. IE: fitting the loop within the 
50ft tall cylinder. If one brings out the sides to keep the top 50ft above 
the 'V' at the bottom the ground losses increase. I think Mike's new shape 
on his E/W loop where the top section maintains a high 'average elevation' 
and the lower section forms a 'V' might be a good compromise. Since he is 
using #8, a conductor of known Rac, the loop current at 1w input would give 
a good figure of merit, allowing calculation of the total Rac.   M..I..K..E 
, we need those numbers! Cold is no excuse. <G>

Bill

>
>
>   >Have you seen any difference in performance of loops with equal wire
>   >length but of varying shape?  Specifically, can you tell a difference 
>when
>   >your loop is "perfectly" round as opposed to being something closer to 
>a
>   >square, with essentially horizontal runs near top, bottom, and/or 
>sides?
>
>   Eric, there's not much difference in the performance of 2500sq ft loops 
>of
>   varying shapes as long as the lower horizontal portion isn't much longer
>   than 50 ft. My measurements indicate loops, having the same area, that 
>are
>   much wider than they are tall have excessive ground losses, but I 
>haven't
>   put a number on this loss, yet. I also have a hunch that circular loops 
>have
>   a higher Q than square loops of the same area but I haven't proven this 
>yet
>   either ....and textbook articles all say there is no difference. Of 
>course
>   most authors claim the TX loop has no practical value at LF, so what do 
>I
>   know!
>
>   Bill

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