The DL82 from Osram is a double diode variable μ triode for use as detector, AGC rectifier and first audio voltage amplifier in broadcast superhet receivers. It was first seen at the 1947 Olympia show and was obsolescent by early 1951. The DH81 was similar and pin compatible but had a higher amplification factor and a higher ra but no vari-μ characteristic.
The triode anode at the top and the small diode anodes near the base.
The Osram paper label.
The triode grid and the diode anodes formed from thin sheet.
The wide glass tube envelope is 32 mm in diameter, and excluding the B8B base pins is 57 mm tall.
References: 1040 & 4018. Type DL82 was first introduced in 1947. See also1947 adverts.
