In days gone by a radio amateur always had a dip meter close to hand in his ‘shack’. Now that people can afford oscilloscopes, the poor old dip meter has lost its importance and is frequently no longer to be seen. Actually this is a shame because many tasks are much easier to carry out with a dip meter. Anyone who’s interested (perhaps the second time around) can easily build one rapidly with this very simple but adequate circuit. The interesting question is namely what do you actually need from a dip meter?
Minimalist Dip Meter Circuit Diagram:
- A visual display of the dip? Nope, the ‘scope can handle that task.
- A large frequency scale? Not necessary, as you can connect a frequency counter for this.
- A selection of coils? We don’t need these because we can use a jumper to change range (no coils to lose any more!).
To take measurements you hold a resonant circuit close to the sensor coil. Tune the rotary capacitor C1 slowly to and fro in order to ﬁnd the resonant frequency, at which the oscillator amplitude decreases somewhat. The frequency can then be read directly off the oscilloscope.
To obtain a very accurate measurement you can additionally connect your frequency counter to the second output.
Author : Burkhard Kainka - Copyright : Elektor