Collectorium · Postage stamp

Progress in Electronics – De Forest Audions

DESCRIPTION OF THE ITEM United States of America, 1973 An aviation stamp with the early Audio vacuum lamps of Lee de Forest, which are the basis for the amplification of radio signals. Catalog identification: Scott C86. Number: 11 cents airmail; colour: vermilion, lilac, olive, brown, deep carmine and black. Unskilled specimen; the condition of the glue has not been checked. CATALOGUE IDENTIFICATION AND PROBABLE VARIANT Working identification: Scott C86. Most likely attribution: Scott C86. Confidence: high. Possible alternatives: Check the back, original glue and overall tagging under UV.

Category

Postage stamp

Year / period

1973

Country

United States of America

Denomination

11 cents airmail

Material

Paper

Collectorium

№ ST-1109