This circuit activates a recorder from the signal obtained from a telephone line in the service. It is used to make automatic call recordings.
This simple operational amplifier tester was published in the November 1987 issue of Radio...
This squelch or silencer for receivers for the 11-meter band was found in the November 1971 issue...
This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in...