Accessible at

https://nandustips.blogspot.com/2014/08/crystal-radio-through-speaker.html

Regards,

Nandu.

 

Nice,you even used the original breadboard!

 

If there's very small power in the radio then maybe less numbers (like 100s or 200s) of turns at input of transformer kills the signal across the transformer (maybe). Can you assume minimum turns with core type?