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Hello to all !
During the Christmas vacation I found some wire
that might be suitable for a loading coil. The wire has a cross section of
4.3 square mm.
I made a coil with a diameter of 38cm and a length
of 20cm that gave an inductance of roughly 900uH.
Measuring the coil Q revealed that having the coil
elevated about 70cm above the floor (concrete) resulted in a Q of 300 and when
putting the coil directly on the floor with the lowest turn about 5cm above the
floor the Q was reduced to 220. The first 30 cm seemed to make a big difference.
>From 30 up to 70cm did not make much change.
I had expected the Q to decrease, however not that
much. The inductance was not very much changed. The change in resonance
frequency was barely detectable.
Having seen on homepages that some of you have the
coil standing quite close to ground it might be wise to elevate it
somewhat.
Wish you all a happy new 2001 !
73 de SM5EUF / Urban
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