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Reply-To: "Dave M"
From: "Dave M"
Subject: Re: How to wind a coil inductor?
X-Newsreader: Microsoft Outlook Express 6.00.2600.0000
Date: Thu, 17 Oct 2002 02:03:29 GMT
NNTP-Posting-Date: Thu, 17 Oct 2002 02:03:29 GMT
Organization: AT&T Worldnet
You are indeed, experiencing a self-resonance at 30 Mhz. You didn't say
what the purpose of the indctor is in your circuit. If it's used in a
resonant circuit, then you probably can't build a single-layer inductor of
30 uh and self-resonance greater than 65 Mhz. You'll have to defer to a
multilayer inductor or a ferrite core. Even then, self resonance of >65 Mhz
is going to be tough.
Are you sure the inductance needs to be that high?
Maybe a more detailed description of the design would yield better
Dave M email@example.com
Remove the xx for my correct email address
"jian" wrote in message
> How to wind a coil inductor?
> I try to make a one layer coil inductor with some problem.
> I need it to work at 65MHz, with an inductance of about 30uH
> without ferrite, just a support.
> I tried 1/4" to 1" diameter. When I used a precision LC digital meter
> to measure the value, it's OK at low frequency but negative value at high
> frequency. When I used a network/impedance analyzer, it becomes wired.
> I think the coil and its parasite capacitance formed a resonance at about
> 30MHz (one can see a peak, then L became negative).
> How should I wind this coil?
> Thanks in advance.
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