This is the circuit for the HM-10ª, an instrument sold by Heathkit. The circuit is from a Radio Electronics from May 1963. The indication is by an analog instrument.
This circuit generates approximately sinusoidal signals from the rectangular signals generated by a 4093...
This two-digit timer was found in the 1983 Special Projects issue of Radio Electronics magazine. The...
This circuit activates a recorder from the signal obtained from a telephone line in the service. It is...