Dear LF Group,
Thank you to everyone who listened out for my signal on 73kHz
last night - I was very pleased to be able to work Mike, G3XDV
with 559 reports both ways. Other reports have been negative so
far; I'm afraid the signal Toni HB9ASB detected wasn't me - my
frequency was close to 72.00kHz. I hope to try again shortly; I
should be able to get my antenna a bit higher before then.
Regarding loops for LF reception, I was involved in some research
work at University of Herts some while ago to develop loop
antennas for LF EMC measurement purposes. We also tried using
ribbon cable, and found the losses and stray capacitance to be
very high - we put this down to the PVC insulation, and the
extremely thin conductors of this type of cable. Almost any other
type of wire is better; we had good results using the inner
conductor and insulation of TV type semi-airspaced coax cable; the
cellular polythene insulation keeps stray C down and has low
losses, even with the wires tightly bundled together. You need
quite a bit of coax, though! Air-spaced windings are probably the
best possible, but are less convenient mechanically.
Cheers, Jim Moritz
73 de M0BMU
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