In this charger the current is limited by the incandescent lamp. Lamps from 40 to 100 W can be used and even connected in parallel, depending on the load.
This source was found in American documentation from the 60's. The diodes are germanium, and the...
We found this circuit in an old QST magazine. The circuit is powered according to the thermostatic relay...
This 3-decade operating range VCO was found in a 90s Popular Electronics. The circuit uses...