De Forest Audions (1915) 11 ¢ — United States, 1973
De Forest Audions (1915) (United States, 1973), face value 11 ¢, “Electronics Progress Issue” series. Photo, catalogue value, details and photo…
- Series
- Electronics Progress Issue
- Issue date
- 1973
- Face value
- 11 ¢
- Colors
- Multicolor