P1 on this Radio Shack circuit is a 6 V lamp with current up to 500 mA depending on Q2. The frequency is given by C1 which can have a modern standard value such as 3.3 uF or even 4.7 uF.
The sophisticated signal tracker/follower with a JFET and integrated circuit 741 was found in a...
The gain of this circuit is given by the value of R1 that depends on the current in the...
This electronic switch published in the July 1970 Radio Electronics magazine allows the...