[TowerTalk] non inductive resistors
jimlux at earthlink.net
Wed Mar 1 07:40:25 EST 2006
At 03:14 PM 2/27/2006, Fabio Grisafi - IT9GSF wrote:
>I wish to know how could I build non-inductive 600-800 Ohm 1KW resistors
>to use with rhombic antennas.
Counter wound or bifilar wound nichrome wire on a suitable form might
work. You can find the nichrome wire in a toaster or electric heater. If
the heater is, say, 2.2kW, then it's drawing about 10 Amp from 220V main,
which implies that the resistance is around 22 ohms. If you can find a
smaller heater (higher resistance).. say, around 1/2 Amp at 220V (100W)
you'll be in the right ballpark (perhaps an aquarium heater?)
A solution of copper sulfate in water makes a great non inductive high
power resistor, but the resistance will change with temperature.
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