RE: Primary tank cables

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ian McLean" <ianmm-at-optusnet-dot-com.au> 

 > Resonant freq is determined by the physical geometry of the
 > capacitor and
 > inductor.  Changing the tank cables should not change the
 > fres unless you
 > change the physical length of the wire, ie, more or less inductance.
 >
 > Performance, however, could increase as you have wire with
 > less resistance
 > and which provides higher peak current in the primary which
 > leads to more
 > intensity in the magnetic field.
 >
 > Dr. Resonance

Oops, yes.  Silly me.  The primary circuit Fres can't be affected by power
input levels.

Sorry for the confusion there Dr. Resonance.  However, upon thinking about
John T's response, I would agree that longer streamers from better power
transfer would surely change the capacitance at the top and affect the
resonant freq of the secondary coil the same sort of way as changing the
topload for another of different dimensions/materials/construction.

If the resonant frequency of the secondary changes in such a situation, then
surely the tuning on the primary would need to change to match this?

Is this not the reason for the feedback winding on VTTC coils to adjust the
Fres of the primary circuit as the streamers grow and affect the Fres of the
secondary?

Some have suggested that the resistance/current carrying capability of the
primary tank cables is well overkill in most situations, and should not
affect output significantly - experience has shown me that, at least in
practise, increasing power transfer this way certainly does improve output
significantly.

Tip: Don't try using GTO-15 cable for primary tank cable at least at similar
power levels (15/120), as it reduces performance a lot.

I think I will try John's suggestion, moving the primary tap outwards in
small steps and see what happens.

Rgs
Ian.