Mal,
I experimented with multiturn 50'x50' vertical TX loops on 185k a couple of
years ago and remember the net gain in the far field signal was much less
than anticipated. Turned out that the additional wires were better-off
connected in parallel. I think the reason is that the soil loss begins to
dominate when turns are added to a loop this size. I'll get out my notes on
these experiments, tonight, and get back to you.
Regards,
Bill Ashlock
Has anyone ever tried a large multi turn loop that resonates directly on
a LF of interest. Most amateurs cannot get a full size one wavelength
loop installed for 160 metres but a 40 metre loop is manageable, so
instead of a 1 turn loop on this freq make it 4 turns plus or minus to
get it to resonate on 160 metres. ie just a large diameter resonant 160m
coil used as an antenna. This principle could be used on 136 khz for
instance, the same 40 m dimensions but with as many turns as nessary to
resonate it on the lower freq of interest.
There will be practical differences and it will probably not work out at
x N turns because of capacitance etc, but the approach to achieve
resonance is the criteria on the lower freqs.
When I say large loop I mean some thing like 40 m and nothing too large,
but sufficient size to have a chance of working and keep the Q
reasonable. The loop would be hanging vertically and the bottom wire at
least 6 feet(2m) off the ground.
73 de Mal/G3KEV
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