RF Probe (T1691E)

This high-impedance probe for oscilloscopes was found in a July 1958 Radio Electronics magazine. The circuit did not include a power supply.

| Clique na imagem para ampliar |

Fast photoelectric relay (CB23760E)
This fast trigger circuit allows the counting of up to 300 pulses per minute. The circuit is from...
Old Intercom (CB18542E)
This intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
Flasher for Mobilete (CB18809E)
This circuit is from an old publication from the 90s, but it can be adapted to operate with LEDs....