Indicated for discriminators adjustment in FM and VHF receivers, this circuit was found in a 90s 73 magazine for radio amateurs. The operational amplifier can be a general-purpose type.
This circuit is suggested by Motorola in its 1990 Linear Databook. The speaker (or headphone is 32...
This circuit was found in a William Sheets. It has 75 ohms of output impedance and can operate up to 20...
This follower, found in a 1982 documentation, has only one amplification step, but it helps in the...