This kit includes parts and a small PCB to substitute a JFET circuit configured as an infinite impedance detector for the usual 1N34 diode detector. With this replacement, your crystal set will generate more volume and reduce audio distortion. Historically this arrangement was used with a triode tube in early AM radio sets. Ideal for those wishing to listen to AM with improved audio linearity. Kit replaces the diode detector in your crystal or TRF set. Assembly time is about one-half hour.