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Old June 10th 07, 06:28 AM posted to rec.radio.swap
Bryan Bryan is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 199
Default Large non-inductive ~450ohm resistor

yea right wrote:
I need a high wattage 100W, 420 - 450 ohm non-inductive resistor to

complete my
terminated folded dipole.

Please contact me at You need
to remove the word REMOVE from the e-mail address.

Thank You


I've purchased noninductive resistors rated at up to 400W as a function of
my duties in RF power engineering. The high power (over 100W *and* high
resistance (over 100 ohms) types are neither inexpensive nor off-the-shelf.
I don't think you're going to be able to hit both the value and power rating
in one package, in small quantities.

That said, Caddock makes an MP9100 series that are rated to 100W in TO-247
packages (100 ohms maximum). They produce other series that are rated at
lower power but are available in higher resistances. Mouser is one of their
distributors. Mouser also stocks Ohmite thickfilm (noninductive) power
resistors. I haven't seen anything like this available from Digi-Key but
Allied and Newark handle Caddock & Ohmite as well as RCD. Many more
manufacturers are listed at the RF Cafe:
http://www.rfcafe.com/vendors/compon...stor_links.htm

Keep in mind that all such resistors would be derated by temperature... they
will handle the rated power only if the case temperature is held to
(typically) 25° C. Most drop to around 50% of rated power as Tc is
increased to 75 ~ 100° C.

Vy 73,
Bryan WA7PRC