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.
This circuit was obtained from a 90s Radio Electronics. The value of R1 determines the scale...
This circuit is from 1992 documentation, but it can still be assembled today, as the components used are...
This circuit is from the Motorola Linear Databook of 1990. The values of the components depend on the...