National CPO Code Practice Oscillator

Object/Artifact

-

Radio Alpha

Image: California Historical Radio Society (CHRS)

Image: California Historical Radio Society (CHRS)

Name/Title

National CPO "Code Practice Oscillator"

Description

Code Practice Oscillator

Category

Code Practice Set

Made/Created

Manufacturer

National Company

Date made

1933 - 1940

Valuations

Value

$3.60

General Notes

Note

Lafayette catalog number 56, p. 55. Lafayette catalog number 78, p. 166. Based on a circuit from the Radio Amateur's Handbooks of the early 1930s. Uses a type 30 tube, and four #2 "flashlight cells," to provide both filament and plate voltages. Number 2 cells are essential D cells. But modern D cells are slightly longer—61.5 mm as opposed to 57 mm for the historic #2–and may not fit in older equipment.