My very simple crystal radio.
by WA4DQS (and every other playful ham!)

Just the usual basics; 1N34A diode, 365pf variable capacitor, fahnestock clips, great-sounding antique (appx 80 year old) high impedence headphones. The coilform is a 2" plastic tube (salvaged and cut from giant roll of plotter paper) with a lose coupled antenna coil, 24 gauge insulated wire 5" on the tuning coil with taps about ever 12 wraps; 1.5" on the antenna coil, no spacing on either. Here in the Los Angeles, CA area, it tunes several broadcast AM stations very well including 640 AM (gotta love those crazies on the "cost to coast" show!) up to around 1010 AM. For the antenna, I just touch the coax lead of my 40m dipole to the antenna clip and I'm in biz. If I double up and also touch my Sigma GT5 multiband HF coax to it, the volume nearly doubles on all stations. I added an earphone jack for using high-impedence earphones.