This reflectometer or standing-wave ratio meter (SWR) was found in a 1980s American documentation. The diodes support general purpose equivalents.
This circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine....
This very simple continuity tester uses a small 1.5 V lamp (type used in flashlights). Can be...
This commercial radio with 3 earphone listening transistors was manufactured in Japan in the...