Stamps, radio & telegraph inventors design type
1 to 6 of 6
Czechoslovakia
postage1959, Dec 7 radio & telegraph inventors unwmk p. 11.75x11.25 (6 stamps)
| X | 25h | multi | Nikola Tesla | |||
| X | 30h | multi | Popov | |||
| X | 35h | multi | Branly | |||
| X | 60h | multi | Marconi | |||
| X | 1k | multi | Hertz | |||
| X | 2k | multi | circuit diagram & Edwin Armstrong |
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