capacitance of this inductor

I have found the following series of coils to be a dandy alternative to winding your own coil when playing around with FM wireless microphone projects:

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The data sheet does not suggest a capacitance value. Anybody care to take a guess? (It's not critical, I'm just wondering.)

Gary Peek Industrologic, Inc.

Reply to
Gary Peek
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Can't you figure it out for yourself? its a simple resonant circuit. Subtract the minimum inductance for a given coil from the maximum, and divide it in half to allow for some tuning range, then use that value and the desired frequency to calculate the required capacitance.

There are eight different coils and 100 US FM channels You don't really expect someone to give you all 800 answers, do you?

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Reply to
Michael A. Terrell

Those are fine, as far as they go, but it's not far, only to 0.465uH. That's a rather limited HF operating region.

Taking the 0.465uH inductor, they don't give the SRF, which many inductor manufaturers provide, but they do test at 50MHz. So if we assume an SRF above 100MHz, that limits the coil's self-capacitance to 5.4pF.

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Reply to
Winfield Hill

In message , dated Fri, 15 Sep 2006, Michael A. Terrell writes

I think he wants the self-capacitance. Only the manufacture or a user would know that, and it SHOULD be on the data sheet.

But if the coils are good to 500 MHz, the self-resonance must be higher than that, so, taking the maximum inductance, find the capacitor that resonates at 500 MHz. The self-capacitance must be less than that.

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Reply to
John Woodgate

Thank you John, you indeed understand the question, and thank you Winfield, since you gave me the quick estimate I was interested in and how to find it. I too agree it should be on the data sheet.

Gary Peek

Reply to
Gary Peek

Bit late maybe but for a bare wire single layer solenoid ...

Coil capacitance = radius in centimetres.

If wire is insulated or moulded in plastic then double the value. john

Reply to
john

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