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Old July 11th 05, 04:38 AM
Tim Wescott
 
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KC4IH wrote:
I need to build a 3db pad, 50 ohm, 10 watt, to reduce the drive to my 6
meter amp. I need 2 X 300 ohms and 1 X 18 Ohm resistors and thought it would
be an easy matter to find them with enough current rating to do the job but
can't find anything larger than 1 watt carbon (not film, which are somewhat
inductive ) resistors. I can find want is called non-inductive wire wound
resistors. I can't understand how a wire wound resistor can be
non-inductive. Could someone explain this?



There used to be great big resistors -- essentially carbon composition
-- that were truely noninductive. I suspect they're still available.
My 1988 handbook has a UHF dummy load design that features a Carborundum
part number 889SP500K. With coolant it's good for more than 1500 watts,
so it may be oversized for you...

You can still find the occasional 2W or 5W carbon comp resistor -- if
you're working at HF you can easily parallel these to get the resistance
that you need.

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Tim Wescott
Wescott Design Services
http://www.wescottdesign.com