Collection: MHL4, 154V, 164V, 41MLF, CV1038, CV3547, NR26, VR38, SMALL SIGNAL, B5

The MHL4 amplifier triode (mu = 20) was not much used in domestic radios because the MH4 (mu = 40) was better suited to the detector/first AF task.   However, the MHL4 did see service in professional and military applications over many years until it was superseded by the Octal based L63 which shows similar characteristics.

The MHL4 was first marketed by Osram in 1929.