This interesting 1924 triode tube receiver was found in a documentation by Gernsback. Observe supply voltages. Coils are for tuned wavebands.
We have other similar setups on this site. This one is from September 1976 Radio Electronics. The...
This low voltage AC control uses a triac. Any TIC series triac can be used and this device must be...
Using germanium transistors, this amplifier provides a 540mW output power when powered by 9V. We...