Ricotjuh wrote:Okay, but what type of capacitor is normally applied at this position?
I assume that Mesa deliberately chose this type ?!
1. Detect small capacitors below 10pF: Because the fixed capacitor capacity below 10pF is too small, use a multimeter to measure, only qualitatively check whether it has leakage, internal short circuit or breakdown. When measuring, you can use the multimeter R × 10k block, use two meter pens to connect the two pins of the capacitor, the resistance should be infinity. If the measured resistance value (the pointer swings to the right) is zero, the capacitor leakage is damaged or internal breakdown.
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2. Detect 10PF~001μF fixed capacitor: judge whether it is good or not by judging whether there is charging phenomenon. The multimeter uses R × 1k block. The beta values of the two triodes are all above 100 and the penetration current is small. A composite tube of 3DG6 and other types of silicon triodes can be selected. The red and black test leads of the multimeter are respectively connected to the emitter e and the collector c of the composite tube. Due to the amplification effect of the composite triode, the charging and discharging process of the measured capacitor is amplified, so that the multimeter pointer swing amplitude is increased, thereby facilitating observation.
It should be noted that during the test operation, especially when measuring the capacitance of a small capacity, it is necessary to repeatedly exchange the two points of the measured capacitor pins to contact A and B to clearly see the swing of the multimeter pointer. For fixed capacitors above 001μF, the multimeter's R×10k block can be used to directly test the capacitor for charging process and whether there is internal short circuit or leakage, and the capacity of the capacitor can be estimated according to the amplitude of the pointer swinging to the right.
