Don't MFJ recommend putting a known value capacitor in parallel with the
coil and measuring the resonance? Then as you know the capacitors value ± 5%
and the MFJ frequency ± 5% you should be able to calculate the approximate
inductance of the coil for large inductors at lower frequencies at least.
Forget it in the VHF region though, stray C between turns become very
significant. I use an AADE LC Meter II and I am delighted with it, it comes
up with very accurate results on some lab standard inductors that we have at
University. Here is a link
http://www.aade.com/lcmeter.htm
73
Conrad G0RUZ
> -----Original Message-----
> From: amps-bounces@contesting.com
> [mailto:amps-bounces@contesting.com] On Behalf Of Will Matney
> Sent: 25 January 2006 01:47
> To: amps@contesting.com
> Subject: Re: [Amps] measuring rf colis
>
> Chuck,
>
> Most stock chokes are measured at frequencies around 1 and 10
> kHz using a precision LCR (bridge) meter. I have both the
> analog and digital bridges here and use both. There are some
> LCR meters by HP and a few others which can measure up to 10
> MHz. Most all stock coils though like Ohmite are measured at
> around 1 to 10 kHz. The three top manufacturers of LCR meters
> is HP, ESI, and GenRad.
>
> Best,
>
> Will
>
> *********** REPLY SEPARATOR ***********
>
> On 1/24/06 at 7:51 PM Partain, Chuck wrote:
>
> >probably touched upon 10k times but..
> >
> >Using my MFJ-259b, measuring some rf coils I have here, sweep the
> >frequency...
> >all coils I have, move all over the place. Is there a standard
> >frequency these are rated at?
> >
> >say a coil is advertised at 10uh. at what frequency? I can
> pretty much
> >determine the current by the size of the wire...??
> >
> >chuck
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>
>
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