Hello Bill,
So based on that a 10m high and 100m long loop should perform as well 32m
high square loop. Doubling the length of a long&low loop should increase
the radiation resistance by 4 and the loss resistance by 2, resulting in an
overal gain of 2 (= 3dB). Does the above fit with your math ?
I'm with you except that a gain of 2 would translate to a 6db increase.
Quadrupling the radiation resistance will give a 6dB gain. But at the same
time the loss resistance is also doubled, what will inflict a 3dB loss. So
overall gain is 'only' 3dB.
Eg :
Assume you gave a loop with a radiation resistance of 1 milli-Ohm and a
loss of 5 Ohm. Putting 400 W into this loop will result in 8.94 A loop
current, the radiated power will be 80 mW (ignoring loop gain for simplicity).
Doublong the loop length will increase the radiation resistance to 4
milli-Ohm and the loss resistance to 10 Ohm. With 400 W th loop current
will now be 6.32 A and the radiated power will be 160mW. This is a 3dB
increase.
The above assumes (simplifies) that the only losses will be 'copper loss'.
73, Rik ON7YD
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