crystal radio: the first real free energy device

[TinselKoala]

TK, how far are you from the transmitter? 3V+ and a few mA is quite a huge signal.
I tested a few Ge transistors, using the base emitter as a diode and none give the same amplitude as a 1970s unbranded Ge signal diode.

Good question, I've been meaning to look it up.   So... with some googling and looking on Google Earth....

The transmitter towers are 4.27 km from our house, and the station radiates only 2500 Watts during the day and only 90 Watts nighttime!
(I knew it was close but I didn't realize how close. It's practically a short walk from home.)
Their antennas are in a directional pattern and we are on the direct line of direction of their radiation pattern.
I'm using the Slinky antenna stretched out to around 3 meters, and the radio is only grounded through the house mains ground wire, instead
of my actual Earth ground rod outside in moist soil. This house has a metal roof and normally it's hard to pick up radio stations
inside.
I agree, the signal received by the radio is extremely strong. When I do use the outside ground wire, I can get more stations but at less
overall power.  So maybe there is some pickup from the house mains, in addition to the power from the radio station itself (at 1.420 MHz).

[pomodoro]

Wow, that's very close. I wonder if you can still light the led at night?  I used to enjoy picking up strange distant AM stations at night, when FM was 'experimental' . I guess they didnt lower their power at night back then.

[TinselKoala]

Yes, it's about 10 pm here now and the green LED is flickering dimly. Not making a lot of light but definitely visible from across the room.

[pomodoro]

Still pretty good, from 90 W and 5km away.  I managed to find a lump of natural Galena amongst a pile of rocks I was given ages ago.  Although the  reception where I am at the moment is very poor and noisy, it it did seem at least as good as the diode. I still haven't got the proper cat whisker,  I'm using a piece of hard copper at the moment.

[Pirate88179]

I have been searching the web for a good design to make my first one.  I think I am advanced (maybe) enough to go a little bit passed the most basic crystal radio designs.  However, I do not want something waaay to complicated for my first one.

Is a variable air cap. a good option for one of these radios in the basic form?  It would seem to me this is better than tapping into loops in the coil placed at fixed points on the length.  I like the design TK used but, that may be above my level to make at this time.  Except for the slinky antenna, that I can do, ha ha.  What a great idea.

Bill