John,
Nice call.
You can find noninductive high voltage resistors from Caddock and
EBE, but they aren't really noninductive to higher frequencies. Ditto
for Dale. However, you can get real noninductive resistors from
Altronics in Arkansas, that they use in their dummy loads and also in
snubber networks. These are BIG resistors though. They use thin film
deposited on a ceramic tube. The standard for RF and noninductive
applications, although the tolerence isn't great, is Kanthal Globar.
Used to be Cesiwid, before that Carborundum Corp. These aren't cheap,
but they are solid resistor (or a tube) made of bulk resistive
material. You can get leaded for lower power or clip in that work in
fuse clips or fancy finger stock caps for high power. Type SP and AS
are the two compositions they will sell you. They aren't cheap (as
none of these companies are) so bring lots of money, or check
hamfests, as you can usually find small globars in the cigar box
sales on tables.
73
John
K5PRO
>
>
>Date: Thu, 08 Feb 2007 07:39:27 -0500
>From: jmltinc@aol.com
>Subject: [Amps] Non-inductive Resistors
>To: amps@contesting.com
>
>Hello all,
>
>Am looking to load a 70cm amplifier grid with about 1K or less of resistance.
>
>This has probably been asked before, but what types of
>"non-inductive" resistors are non-inducive up to 1 GHz? And, if
>carbon composition is the only choice, where can you find 3W these
>days?
>
>I have found some sources state carbon film and metal film resistors
>are non-inductive, but rate them to 100 MHz.
>
>Thanks,
>-John, N9RF
>
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