This circuit tests quartz crystals of frequencies between 100 kHz and 10 MHz. The circuit is from an old American documentation and can be assembled with a BF245 transistor. The circuit provides the indication by lighting the 12 V x 14 mA lamp. This lamp is not easy to find and can be replaced by an LED. Capacitor C1 can be 47 pF ceramic current standard value and 250 pF can be 220 pF.
| Clique na imagem para ampliar |
