No. That capacitor would charge at a few volts, i.e. the sum between the voltage on a conducting LED and the voltage on a conducting silicon diode (the base-collector junction).
So the capacitor would initially divert a part of the discharge current from the LED, but later it would discharge itself through the LED. So it might make the current impulse through the LED smaller and wider. Such a capacitor would increase the probability that the transistor would be damaged by the periodic breakdowns, by extracting a big current pulse through the base. Depending on the transistor structure, a capacitor on the base could also stop the oscillations, because the current extracted through the base could eliminate the negative resistance that appears on the voltage-current characteristic in the breakdown region when the base is not connected or it is connected somewhere only through a big resistor.
The frequency is very easily adjustable without changing the schematics, by changing the value of the resistor that charges the capacitor, before the breakdown voltage is reached, or by changing the value of the capacitor.
The RC product determines the charging time, which constitutes most of the period of the pulses.
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No. That capacitor would charge at a few volts, i.e. the sum between the voltage on a conducting LED and the voltage on a conducting silicon diode (the base-collector junction).
So the capacitor would initially divert a part of the discharge current from the LED, but later it would discharge itself through the LED. So it might make the current impulse through the LED smaller and wider. Such a capacitor would increase the probability that the transistor would be damaged by the periodic breakdowns, by extracting a big current pulse through the base. Depending on the transistor structure, a capacitor on the base could also stop the oscillations, because the current extracted through the base could eliminate the negative resistance that appears on the voltage-current characteristic in the breakdown region when the base is not connected or it is connected somewhere only through a big resistor.
The frequency is very easily adjustable without changing the schematics, by changing the value of the resistor that charges the capacitor, before the breakdown voltage is reached, or by changing the value of the capacitor.
The RC product determines the charging time, which constitutes most of the period of the pulses.