Re: How do you test a toroid?

John Lonigro

That reminds me. I've got an "Elsie" kit which measures either inductance or capacitance and displays it via CW. It doesn't seem to work, probably because I have yet to build the stupid thing!! Maybe I should put that near the top of my list of kits to build. I can't remember but it probably cost less than that Chinese meter. Its only advantage is it provides some CW practice while measuring your components.

In answer to someone's question, the MFJ-259 can indeed measure inductance. As I recall, you put a 50 ohm resistor in series with an LC circuit, find where the SWR is 1.0, and then do a little math to calculate the inductance, assuming you accurately know the value of the capacitor. The appropriate equation is in the handbook (probably any edition) and the instructions are in the MFJ manual. The L and C need to produce resonance at a frequency covered by the MFJ-259. Don't try to measure that 2 Henry choke in your junk box!

John AA0VE

On 03/27/2013 06:37 PM, w1sfr wrote:

I went ahead and ordered one. Free shipping from China for $25.


--- In <>, Bill Cromwell <wrcromwell@...> wrote:

On Wed, 2013-03-27 at 14:03 -0700, chuck adams wrote:

On 03/27/2013 01:50 PM, Lee Mairs (SAG) wrote:

Check eBay. The Chinese have an LC ESR meter that is about $25.
Has good reviews and works great.
73 de Lee

A few days ago on qrp-tech, some one recommended the following.
I ordered one and will run some tests on it, but the fact that it does
so much is appealing, especially the ESR since I haven't gotten around
to homebrewing one and the bench queue is too long now. :-)

Maybe some one has already gotten the same model already.


chuck, k7qo



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Bill KU8H

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