[AMRadio] Re: Choke calculations

Patrick Jankowiak recycler at swbell.net
Sun Aug 21 18:12:56 EDT 2005

Now THAT is the key to happiness!

Since we might wish to also measure the inductance of a choke with some 
amount of DC current flowing through it, does anyone have an idea how to do 

In an example of a 10H choke, which would have 3768 ohms impedance, how 
would I pass 0.5 amp through it's 80 ohms of DC resistance without messing 
up the impedance measurement method?

To me the obstacle looks like the issue of the power supply feeding the 
choke having a very low impedance compare to the measurement value to be 
made. Add to this the desire for a range of 0.1 to 100H and it's a real 
issue, at least from a calibration standpoint.

I am certain some one on this list has done this before. It has to have 
been done in the choke factories of olden times!


> From: "John Coleman ARS WA5BXO" <wa5bxo2005 at pctechref.com>
> Subject: [AMRadio] Choke calculations
> To: "AMRadio" <AMRadio at mailman.qth.net>
> Message-ID: <000001c5a5f6$952ded00$0a01a8c0 at home1>
> Content-Type: text/plain;	charset="us-ascii"
> Hey Bob:
> 	 I just realized that each Henry of inductance is equivalent to
> 376.8 ohms at 60 Hz.  I don't know why, but at my age now, little
> revelations of that nature excite me. 
> John,

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