Institute Newton C. Braga

Circuit Bench

Two decades high frequency VCO (CB20830E)
Using operational amplifiers of the time, we found this circuit in documentation from the 90s. The...
5 to 5.5 MHz VFO (CB13862E)
We found this circuit in a documentation for radio amateurs from 1975. The FET can be the BF245 and...
1 kHz Tuned Filter (CB14845E)
This filter can use almost any common operational amplifier and needs a symmetrical power source. The...