Linear Ohmmeter LM11 and TL431 (CB14548E)

We found this circuit in Motorola's Linear Databook in 1990. Integrated circuits are somewhat difficult to obtain today.

2 Door Announcer (CB4757E)
This two-door doorbell was found in a 1990s US publication. The circuit is still current as...
Medical instrumentation preamplifier (CB7235E)
Suggested by Intersil in documentation from the 90's, this circuit is valid for modern operating...
10 to 80 MHz Oscillator (CB6511E)
We found this circuit in an old RF documentation. The circuit must employ RF transistors and the...