John, I made a quick layout for the original Adams bug detector,
bringing it up to date with a TL072 IC Chip. It works really well.
Because the MC34002 is now superseded It works very well as shown here
using the replacement TL072.
Similarly, almost any germanium or shottky diode will work. The one in
this circuit is a BAT-41. The circuit was tested using 146MHz and
444MHz transmitters from across a room, and a Wi-Fi signal at 3 feet.
Nice circuit. Pete Zenner, KE0BRS