The method of measuring resistance is measured with a multimeter FET source electrode and the drain, gate and source pole resistance value indicated by the resistance value between the gate and drain, gate G1 and the gate G2 and the FET manual are consistent to distinguish good and bad of the tube.
Specific methods :
- first placed in the multimeter R × 10 or R × 100 files, measuring the resistance between the source S and drain D, usually in the tens of ohms to thousands of Europe-wide (in the manual shows a variety of different models tube, the resistance value is not the same), if the measured resistance is greater than normal, may be due to internal poor contact;
- If the measured resistance is infinite, may be internally broken pole. Then placed in the multimeter R × 10k file, and then measured between the gate G1 and G2, gate and source, the resistance value between the gate and drain, when measured its various resistor values are infinite, the Description tube is normal;
- if measured to get above the resistance is too small for the pathway, then the tube is bad. To note that the two grids is broken in the tube pole available component substitution method to detect.