That will be a very interesting antenna to hear about. I hope you can put it
up real soon. I think someone over on this side used a small receive sized
multi-turn loop for transmit with the 1w and actually radiated a signal,
although weak. Now maybe the 40m on a side multi-turn loop will be better.
136kc will hurt the efficiency. The station over here was on 180kc.
Mike>WE0H
http://www.geocities.com/we0h/index.html
-----Original Message-----
From: [email protected] [mailto:[email protected]]On Behalf
Of gii3kev
Sent: Monday, March 04, 2002 11:00 AM
To: rsgb rsgb
Subject: LF: loops
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.
Maybe someone has already tried this procedure. I know there are multi
turn small loops of various configurations, series wound, parallel
wound, series tuned, parallel tuned etc and preamps but I do not recall
any research figures published for large multi turn loops.
When I get time I intend to put up a large loop and instead of a single
turn suitably resonated on 136 khz I am thinking along the lines of the
series multi turn loop.
73 de Mal/G3KEV
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