On Mon, 27 Apr 2009 16:34:23 -0700 (PDT), K7ITM wrote:

If you have very sensitive earphones (and sensitive ears!) and a good
antenna, what may matter more than keeping the loss down to an
absolute minimum is getting rid of interfering signals. A single-
tuned circuit with 10kHz -3dB bandwidth offers only 20dB attenuation
of a signal 50kHz away, and a signal 200kHz away is attenuated only
about 32dB (assuming I didn't mess up my mental arithmetic). That's
not a lot if you live in a metropolitan area with several stations
nearby, and you want to hear the ones from far away. You can make the
tuner with two or even three tuned circuits that are properly coupled,
and get much better attenuation of those unwanted signals. But more
tuned circuits means more loss in the tuner, too, even if you use high
Q coils.

Unless you live very near an international SW broadcasters, how do you
expect to get any usable amplitude modulated signal in the middle of
the SW band for your crystal set ?

To make the situation even worse, the power delivered by a matched
dipole at 10 MHz is only 1/100 (-20 dB) of the power delivered by a
matched dipole on 1 MHz due to the antenna capture area.

Paul OH3LWR