Is this a real patent?

Yes — the original drawing as filed at the U.S. Patent Office, cleaned and printed. Public domain by law.

Printed in Europe on 200 g/m² matte paper. Small sizes ship flat, 50 × 70 ships rolled in a tube. Tracking by email.

What if it arrives damaged?

Send a photo within 7 days and we reprint and reship it free.

US 879,532Space telegraphy1908

PD-38 · US 879,532

Name: Space telegraphy Patent Print (1908)
Brand: PATENT DEPT.
SKU: PD-38
Availability: InStock

De Forest's audion triode, 1908 — the first electronic amplifier, grandfather of every radio and computer tube.

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PD-38 · US 879,532 · Filed January 29, 1907 ·

Is this a real patent?: Yes — the original drawing as filed at the U.S. Patent Office, cleaned and printed. Public domain by law.
How is it shipped?: Printed in Europe on 200 g/m² matte paper. Small sizes ship flat, 50 × 70 ships rolled in a tube. Tracking by email.
What if it arrives damaged?: Send a photo within 7 days and we reprint and reship it free.