Dear Henny,
the coil consists of seven ordinary ten-liter polypropylene household
buckets, inserted upside-down into one another. The diameter of the buckets
is about 25 cm at the bottom and 21 cm near the top. Each bucket carries 460
turns of 0.4 mm enameled wire. The lead from the top end of one winding to
th bottom end of the next has to run alomg the winding, and is insulated
with several strips of tape an foam material. Total DC resistance is about
320 ohms.
The resonance is adjusted by the amount of overlap. Inserting the buckets
deeper into one another lowers the frequency by enhancing the mutual
inductive coupling, along with a slightly higher inter-layer capacitance. My
240 pF antenna requires a total length of about 60 cm for 9 kHz. For the 500
pF kite antenna I need only five buckets, and with larger spacing.
Best 73,
Markus (DF6NM)
From: henny van elst
Sent: Wednesday, November 17, 2010 6:43 PM
To: [email protected]
Subject: Re: LF: XDV QRSS60 137k
Hello Marcus,
I am also busy with an coil for 8,970Khz,can You tel me the diameter of the
coil on the roof?
henny cpm
best 73's
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