raypsi wrote:

Hey OM:

What you claim may be true, but if I use a pair of 2000 ohm headphones
and have 100 millivolts into those phones, I would developed a power
into those headphones of 5 microwatts. Now if the voltage goes up 4
times to 400 millivolts the power developed into the phones is 80
microwatts. So it don't matter what the detector impedance is. The
headphones don't care what the impedance is, in this case.

Yes it does. And no, your math is wrong. Phones don't respond to watts.

In a simple crystal radio the voltage is gained by NOT loading down the
preceeding circuit. If you load down a simple LC circuit with a
doubler/quadrupler as opposed to 'one clean diode' then you lose more
than you gain. And you take an additional hit on selectivity because
the Q of the RF circuit becomes loaded excessively. Thats why the
doubler/quadrupler schemes that look good on paper don't pass muster
with xtal radio enthusiasts.

Detector impedance, headphone impedance are the meat and potatoes in
"dx" crystal radio circuits. Its a house of mirrors, so to speak.
Poor impedance match at the fones will kill RF selectivity, for example.
Yes, you have to look at it that way.

Doesn't matter much with a Rocket Radio or a Cub Scout radio but if you
get into the high end of xtal sets its very important.

-Bill