HALLICRAFTER EC-1B User Manual

Echophone EC-1B

Made by Hallicrafters, this three-band (BC and two short wave bands) six-tube AC-DC receiver is
very similar in design to the early six-tube S-38 which replaced it. Tube line-up and function are
identical with the use of two 12SQ7's (one for bfo/ noise limiter and one for detector/ AVC/ audio
amplifier). Other tubes used for both the EC-1B and the S-38 are 35Z5 (rectifier), 35L6 (audio
output), 12SA7 (mixer) and 12SK7 (I.F. amplifier). The schematic for the EC-1B is shown in
Rider's Volume 16. The radio was introduced in 1946. The schematic in the manual is dated
December 1945.

The EC-1B is nearly identical to model EC-1A. Both are updated versions of the EC-1. The
EC-1B uses an inductor link to the oscillator coil for the bandspread with a cheaper
broadcast-type variable capacitor. The EC-1A uses the more conventional and more expensive
dual-control variable capacitor. An early ad for the EC-1A in the January 1946 Radio News
features Hogarth (see the EC-1) dreaming about it. The Hallicrafters S-41G (gray) and S-41W
(white) are electrically and mechanically identical to the EC-1A/B with the main differences being
color and knob style.

Safety note: The EC-1B and others mechanically and electrically identical to it have one side of
the power line connected to the chassis by way of the power switch. There are grommets
separating and insulating the metal cabinet from the chassis. That insulation must remain intact.
For safety, it is strongly recommended that the EC-1B (and other AC-DC style radios) be
operated from an isolation transformer.
If you must plug it in directly, at the very least plug it into a GFCI (ground -fault circuit
interrupter) outlet.