This circuit uses a CMOS integrated circuit as a basic element and can be combined with the previous circuits. The circuit is from a Radio Electronics from May 1990.
This circuit generates a sinusoidal signal with only -80 dB THD. The circuit was found in a 90's...
This circuit is from a 1980s Motorola documentation. The circuit can be set to fire from 60 to 120...
If interference occurs in several receivers, much more interesting than placing a filter on each...