The diode is a 1N34A, from a proper Crystal Radio supplier. I did proof it.
The v cap is also from a proper Crystal Radio supplier. I did proof it.
To ping the signal... Replace the antenna with a Function Generator and listen to the radio, for tone?
Thanks
Do you have a function generator?
If so, you can couple its output very loosely to the Crystal radio & tune across the range of frequencies you expect to be receiving.
Most function generators go up to 1MHz, so, with the gen set to sinewaves, as you tune across the LC tuning circuits expected resonant frequency, you should hear the background hiss suddenly drop, as the unmodulated carrier from the FG passes the actual frequency of resonance.
As there is no modulation, you won't hear any tone.
To actually hear a tone, try a square wave or sawtooth at around 1kHz.
Such waveforms are rich in harmonics, which the radio will see as a MF carrier pulsed at 1kHz----near enough to AM!!
Again---- put the tiny little RF chokes back in the parts bin, & wind a proper coil.
If you look at enough websites*, you should get a good idea of the number of turns on a given sized form.
As to not always needing an antenna, this is "sort of" correct.
If you have an earth connection to a metal water pipe, the radio will "use the earth as an antenna".
Another old time trick was to clip a short antenna lead to the metal of an old style dial phone.
This would capacitive lay couple to the phone wires.
Millions of kids over many decades made Crystal sets that "worked".
Making really good ones is a specialist hobby, but you might be best to stick with basics first.
* PS----take a look at this:-
http://www.techlib.com/electronics/crystal.html