High impedance millivoltmeter (CB20611E)

We found this circuit in an old American documentation. The components are from that period and may present difficulties in obtaining them.

| Clique na imagem para ampliar |

Astable Triggered CMOS (CB10494E)
This circuit is from a 1998 Electronics Now and can be easily assembled since it uses a common...
Intercom (CB5012E)
I found this circuit on a December 1976 Radio Elettronica. The Italian magazine no longer exists, but...
Divider with the 4046 IC (CB25003E)
The purpose of this PLL circuit that we found in the November 1986 Radio Electronics magazine is...