The 'local' contact went fine, but I wanted more audio so I wouldn't have to struggle hearing as I did with the first contact.

I built up a basic amplifier circuit using a LM386 chip. Now I could use 'walkman' style headphones. Also, as an experiment, I hooked up a speaker to the audio output on the amp and, on loud signals, I could even hear them on the speaker...neat!

Don't get me wrong here...I love building crystal sets and you'll need high impedance phones for basic sets. Besides, you can can get/fabricate pads for these headphones. Also, crystal earpieces are still available new, and only need a resistor across them to work, if you want to keep the simple set and reduce the size.

Next, I had seen easy pi-net circuits in many Sprat journals so I just substituted the parallel tapped tank circuit with a pi-net. Much easier to make plus, some harmonic suppression to boot.