Has problem to check my crystals, search for a simple circuit to use, I found the a circuit from:
**broken link removed**
I used 2N3904 instead of the proposed 2N3563 transistor, as per the designer recommendations. After constructing the circuit using bread board, the LED is always ON even when the crystal is not connected.
Has problem to check my crystals, search for a simple circuit to use, I found the a circuit from:
**broken link removed**
I used 2N3904 instead of the proposed 2N3563 transistor, as per the designer recommendations. After constructing the circuit using bread board, the LED is always ON even when the crystal is not connected.
O.K. I would like to go a step further and make the circuit to check my 20 MHz crystal ( It is desigened to check xtls with frequency range 2 MHz upto 8 MHz ). What part to modify, is it the transistors or the capacitors also.
A single CMOS inverter has a weak output with barely enough current to light an LED brightly so three are paralleled to make the LED light brightly, besides there are six inverters on a CD4069 so you might as well use them all.
CD4069 can be found in many of my old junkyard, but 10M resistor is very high value that I dont remember if I came across an time. But no problem my supplier have it for $0.10 each.