Grid dipper

Only a handful of components are needed to build an intrument which is indispensable in any RF workshop: the grid dip meter or 'dipper'. The main function of this clever piece of test equipment is to determine the resonance frequency of unknown tuned circuits within a certain range (here, 1.5 to 80 MHz). Apart from this, the dipper doubles as an RF signal generator and an absorption frequency meter. Some amateurs even use it to repair radios or tune short-wave antennas!