>Gentlemen,
>
>My paint can oil-filled dummy load does not provide
>the time duration necessary to achieve perfect tuning
>as it gets very hot and pops off the vent cap in addition
>to changing its internal resistance.
>
>Who makes a 3KW or better dummy load that's
>affordable?
>
>There are BC quality units available and they are
>between 1 and 2 thousand dollars.
>
>I would consider HB'ng a dummy load in a 5 gallon
>metal bucket.
** The most practical way to cool a 50-ohm terminating resistor is with
moving water. Bird Co. makes a series of terminations that do this. A
sealed 3" ABS tube - with glued-on inlet and outlet garden-hose fittings
- directs water around the resistor. 6-gallons per minute will carry
away at least 15,000W of heat. To maintain constant Z with freq change,
a tapered conductor is placed parallel with the resistor - with the
widest spacing being at the coaxial RF connector end. I currently have
a suitable resistor for building such a terminator on back order at
Kanthal-Globar. I plan to use ordinary plastic pipe for the resistor
housing. My estimate is that the cost of the plumbing material will be
under $10 per water-cooled terminator. The water discharge can be used
to sprinkle the lawn or garden.
>
>Your opinions and advice are always welcome.
>
>Hal
>KA1XO
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>
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