Matching antenna (CB7458E)

The coil and sockets of this circuit found in a QST depend on the frequency band that is intended to be tuned.

Scale Adapter for Multimeter (CB16845E)
The purpose of this circuit is to allow common analog multimeters to measure low resistances, on...
Light-sensitive circuit (CB23962E)
We found this circuit in a Radio Electronics issue from July 1969. The lamp remains on until C1...
Slave flash trigger (CB8704E)
This circuit was found in a 90s Popular Electronics. The sensor can be any phototransistor. ...