The spacing between turns,the number of turns,the wire diameter and the type of torrid all have an effect on the inductance. I use one of the "cheap" inductance meter and the readings are very close to a instrument costing nearly £100 so for me the inexpensive one is good.
From: BITX20@groups.io <BITX20@groups.io> on behalf of hickmodawg@... <hickmodawg@...>
Sent: Saturday, November 2, 2019 8:05:28 PM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] ubitx LPF #bitx20 #bitx20help #bitx40 #bitx40help #ubitx #ubitx-help
Why not use the online calculators to get an estimate of the number of turns we need, and then use an inexpensive meter to fine-tune the number and arrangement of windings before installing the toroid on the
board? I got a cheap LC100-A meter on EBay that measures inductance and I was a little shocked to see how the inductance values of my toroids changed just from moving the windings closer or farther apart, not just from adding or subtracting
winds. It seems to me, that the size and composition of the toroid, and the spacing of the windings may have an effect on the resulting inductance, not just the
number of windings. I’m really still quite new to this, but, I’m wondering, why not use a meter before installing our toroids onto the board?
Is it because these cheap meters are very inaccurate?