[Lowfer] Variometer tickler coil adjustment - Question ???

[Ed Phillips]

Andy:

The position you describe [movable coil at right angles to main coil] 
corresponds to minimum inductance so you are probably not quite tuned 
there and you need to pull a few more turns off just to be sure you're 
in resonance. You are correct that change in inductance for a given 
rotation of the coil is maximum at that position - that's the point at 
which the extra inductance changes from adding to the mail coil or else 
subtracting, depending on the polarity of the winding.

Ed

Andy - KU4XR wrote:

>Hello all:
>
>Before I start to messin with my variometer, I need some advice.
>        **************************************************
>Is there a physical position of the tickler coil in relation to
>the fixed coil the provides Maximum " Q " in the variometer ??
>        **************************************************
>Today I added an extra 9 wires to my lowFER top-hat, and it
>considerably reduced the needed Inductance. Now , my tuning is
>razor sharp, and the Tickler coil is 90* offset from the fixed
>coil ( picture an " L " ), I am assuming ( possibly wrongly ),
>that the sharp tuning is because the adjustment is right at the 
>knee-over point in tuning, and not necessarily a higher " Q ".
>Unwinding a few turns of the fixed coil would allow tuning back 
>towards the Max. position on the variometer, broader tuning peak,
>and a little less coil resistance ( most likely minute' ).
>
>Before I start unwinding turns, what are your opinions ??
>
>Thanks for your input;  73 for now :::
>
>
>Andy - KU4XR - EM75xr - Friendsville, TN.
>