We found this 50 kHz 25 MHz crystal tester in a 1978 QST magazine. The FET can be the BF245 and the indicator can be the lowest current range of a common multimeter. The transformer is 6 V x 300 mA or more and the inductors are 100 mH or more.
We found this 50 kHz 25 MHz crystal tester in a 1978 QST magazine. The FET can be the BF245 and the indicator can be the lowest current range of a common multimeter. The transformer is 6 V x 300 mA or more and the inductors are 100 mH or more.