Loaded Q or unloaded Q? If the load is in parallel with the tank and
a fixed value, decrease the reactance of the tank elements. If the
fixed resistive load is in series with the L and C, increase the
reactance of the tank elements. Generally you should design the Q to
fit the task. (You could expand on that: generally you should design
the circuit to fit the task...)

Unloaded Q is increased by things like using the right core material
and right winding techniques. There's not a simple answer. For
air-core coils, the larger the coil the higher the Q possible, up to
the point where radiation becomes significant. You might hear that
helical resonators are very high Q, but actually the same coil in
freespace will be higher Q, so long as it's not so large it radiates a
lot. Reg has a program that estimates unloaded Q of air-core RF
coils.

It's a fairly complex subject...don't expect one answer to fit all
situations.

Cheers,
Tom

Paul Burridge wrote in message . ..
Hi guys,

ISTR that one can improve Q in resonant tanks by having a low L-C
ratio. Or was it high L-C ratio. I can't remember but need to know.
Can any kind soul help me out? Thanks.

p.