This assembly is from 1957 from a Raytheon manual, but can be modernized using a BC548, 6 V power supply and common 100 mA relays.
This circuit has a frequency range of 30 Hz to 100 kHz with an output signal of 1 Vrms. We found...
In the figure we have a second order filter with very high input impedance, using an operational...
Using the HA2400 this circuit can generate signals of a few megahertz depending on R and C. The...