Your original question suggested an ideal transformer, which the loop
antenna undoubtedly is not, therefore the detailed answer is more
complicated. The loop impedance is an LCR network that would require a more
detailed study, which I am not able to offer right now.

If your 1000 pF gets the job done, that is probably a good solution that
tunes out the net effective inductive reactance.

Bill W0IYH

TRABEM wrote in message ...
On Sun, 18 Sep 2005 17:47:09 GMT, "William E. Sabin"
wrote:

If the transformer has a step-up turns ratio (from primary to secondary)
then the resistance, inductive reactance and capacitive reactance
connected
to the secondary (as measured at the primary) decrease as the square of
the
turns ratio. Therefore effective capacitance measured at the primary
increases as the square of the turns ratio. For a step-down transformer
the
effects are the opposite.


OK Bill,

I have a series tuned loop that is resonant with 1000 pf and fed into
a 10 to one step up transformer.

If I remove the 1000 pF cap completely, I can resonate the loop at the
same frequency with 10 pF in the secondary?

It almost sounds too good to be true::

Regards,

T