Suggested by Philips documentation from 1968, this circuit uses components from the era that can be replaced by modern equivalent types. The double transistor can be replaced by a matched pair.
Found in a 1960 General Electric documentation, this crowbar circuit blows the fuse in case of...
This circuit was originally designed for testing crystals used in color televisions, but it works...
This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from...