Fifty years ago this month, the January 1968 issue of Electronics Illustrated offered just the thing for aspiring spooks, namely, this homemade electronic bug. Housed in the ubiquitous cigarette pack, the tiny device transmitted on the AM band, and could be picked up 10-50 feet away.
It was billed as suitable for listening in on “your neighbor, close friend, worst enemy, bookie, business partner, the business competition, or even you.”
As shown here, the parts had a price tag of about $20, although the article noted that the price might be lower if slightly larger components would be acceptable.
The circuit used four Motorola transistors, three 2N4123’s and one MPS3646 handling the RF output duties. It was constructed on a circuit board with holes drilled for the components, with wiring on the other side.
The battery shown here is a Burgess H-177 9.8 volt battery, although the article pointed out that a standard 9 volt battery could be used if the slightly larger size were acceptable.