You can adjust the gap easily by hand with some fine grit sandpaper.
Place the paper on a flat surface, and lap the core until the outer
legs are slightly shorter, making the gap smaller.
There is usually enough tolerance between the bobbin and core so it
will still close fully on the bobbin.
To make the gap larger you can sand just the center leg, but this is
more difficult to get straight.
It is easier to put spacers in between (paper etc.) and live with half
of the gap on the outer legs, even if that is not ideal.
I keep an assortment of pre-ground cores in certain steps, and often
grind the gap smaller for correct inductance.
ST
On Fri, Sep 12, 2014 at 4:32 PM, Manfred Mornhinweg manfred@...
[TekScopes] <TekScopes@...> wrote:
Maybe I can even find a core with a smaller airgap.
