Field strength meter (CB8220E)

This passive tuned circuit was found in a 90s Popular Electronics. The coils must be according to the monitored waveband.

| Clique na imagem para ampliar |

Power Outage Alarm (CB5952E)
We found this circuit very simple in an old documentation. The relay is high voltage sensitive, but...
Triac isolated trigger (CB8030E)
This circuit was found in a Radio Electronics from 1970. The coupler with LDR is from that time,...
Diac Phase Control (CB13368E)
This circuit is from a publication about thyristors from the 70s. It consists of a pulse generator...