Alberto I2PHD,
As a matter of fact, at 137 kHz the inductance values aren't so big
to make it impractical to wind them. At 9 kHz things are a bit
different...<
Alberto, first of all thanks for providing ARGO, I have played around with
it and found it very useful.
About the coils on 9 kHz: I am using a u-shaped core with a closing bar on
top made of ferrite material (special thanks to Markus, DF6NM). Using this
setup I have a coil wit 1 H (one Henry) inductivity, lifting the ferrite
bar on top by means of a screw some tenth of a millimeter I can fine-tune
this coil between about 0.5 and 1 H. With 10 Watts output I achieve a
current of roughly 130 mA into my 18m vertical ... sufficient for about
770m distance ...
Best 73
Geri, DK8KW (W1KW)
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