Emerson 558

Emerson 558

Made by the Emerson Radio and Phonograph Corporation of N.Y., dating from the mid 1940s, this US built portable measures 218x110x62mm, and weighs in at a hefty 1.2kg without batteries. The case is made from a plastic resembling ivory, with a peculiar smell.

Emerson 558 open case

The circuit is a medium wave only superhet using four miniature B7G valves, covering 550 - 1600kHz. Reception is via frame aerial located in the lid. Lifting the lid automatically switches the radio on, other controls being volume and tuning. The valve lineup is conventional with a 1R5 (DK91) frequency changer, 1T4 (DF91) vari-mu IF amp., 1S5 (DAF91) detector/audio amp. followed by a 3S4 (DL92) single ended class-A output stage. The low-tension ("A") battery is a standard 1.5v "D" cell, while the HT ("B") battery is a 67.5v US Eveready No. 467. The wired chassis construction is very compact, with the unusual disposition of valves, IF transformers and other major parts designed to make use of every bit of space. The LT battery clips can be seen to the left of the speaker magnet, while the space to the right of the airspaced tuning gang is reserved for the HT battery. Starting at the top left and moving clockwise, the lone valve is the 1R5 with the first IF transformer behind, followed by the oscillator coil and on/off switch, tuning gang, 1T4, second IF can, 1S5 with 3S4 behind, and finally the output transformer.

Emerson 558 front panel

Emerson 558 diagram