Philips AZ4 full-wave rectifier with black smooth plates on the classic side-contact base - a used example with both rectifier sections testing well above minimum. No box.
Both rectifier sections (D1 and D2) tested well above minimum.
AZ4 = WE56
Similar, different base: AZ12. Similar, different base and heater: 1861. Later replacement rectifiers (different bases, circuit check required): EZ81, GZ32, GZ34.
The AZ4 is a full-wave vacuum rectifier introduced by Philips in 1938, built on the European side-contact P8A base with a directly heated 4V / 2.3A filament. It served as the power-supply rectifier in a large number of European radio receivers, valued for its robust current capability in mains-powered sets, and stayed in production well into the 1960s. As a directly heated full-wave type it delivers both rectified half-cycles from a single envelope, and its side-contact base places it in the Continental design tradition later superseded by noval and octal rectifiers such as the EZ81 and GZ34.
A strong-testing Philips AZ4 to bring your vintage set back to life. Original rectifiers like this are getting scarce.
SKU: 89