have to stop vibration phenomenon
    Analysis: in the design of the oscillator circuit often have a negative resistance value, that value is typically the negative resistance circuit, with the feedback coefficient, related to the magnification of the active element. Quartz resonator as a frequency-selective element itself has an equivalent resonant resistance. The resonant resistance of the resonator package size, the frequency, the size of the resonator is generally smaller, the resonance resistance; lower the frequency, the greater the resonance resistance. When the negative resistance of the circuit is less than 2 times the resistance of the quartz resonator oscillation becomes unstable. In particular, the component values ​​of the operating voltage of the oscillation circuit fluctuates, the active element and the dispersion of the feedback loop will deviate from the design value of the negative resistance. In the actual working environment temperature changes, the resonance resistance of quartz resonator will change, destruction of the oscillation circuit is required for normal working conditions.
     The solution, one of the circuit feedback circuit to adjust and improve the negative resistance, the second is to reduce resonance resistance of quartz resonator. The first method is generally easier to reduce the resistance of the quartz resonator is sometimes difficult, significantly increase manufacturing costs. To ensure that the circuit is working properly, it is recommended about 3-10 times during the circuit design of negative resistance in quartz resonator resistance. In small size large size quartz resonator replacement resonator (as with HC-49S replacement HC-49U) Special attention should adjust circuit parameters. Problems and phenomena: Install quartz resonator oscillation circuit instability, and some have to stop vibration phenomena Analysis: usually oscillation circuit design will have a negative resistance value, this value is usually negative resistance circuit of the feedback factor, there source elements related to the magnification. Quartz resonator as a frequency-selective element itself has an equivalent resonant resistance. The resonant resistance of the resonator package size, frequency-dependent