Found in a 90’s HAM Radio, this circuit is used for an optical communications system or even audio transmission by optical fiber. The components are common.
This experimental AM radio circuit was found in a 1979 English magazine. It can be fitted with a...
This is a variation of the two previous circuits but controlling two LEDs. The brightness of the...
This circuit is the receiver for the CB13997E. The transistor can be the BC548. We also found this...