This is one of the many versions of this type of indicator that the reader can find on our website. This is from Mullard's 1969 documentation. The indicator is 95 uA (100 uA).
This circuit has both frequency and duty cycle control. We found it in the October 1992 Radio...
This power supply is indicated for the supply of not very powerful car radios of the AM and FM...
In the absence of a modulation signal, the carrier of this simple short-range transmitter is cut...