The transistor can be a BC548 and the coil has the following characteristics for 1 MHz. L1 has 80 turns of wire 28 in a ferrite rod and L2 of 30 and 40 turns.
We found this circuit in a November 1970 Radio Electronics. It uses a PUT or programmable...
We found this circuit in a technical documentation from the 1970s. It converts low frequency...
This modulated siren was found in the December 1974 issue of Radio Electronics magazine. A higher...