U.S. #1500

6¢ Marconi's Spark Coil & Gap
Electronics Progress Issue 

Issue Date: July 10, 1973

City: New York, NY

Quantity: 53,005,000

Printed By: Bureau of Engraving and Printing

Printing Method: Lithographed, engraved

Perforations:11

Color: Lilac and multicolo...  more

U.S. #1500

6¢ Marconi's Spark Coil & Gap
Electronics Progress Issue 

Issue Date: July 10, 1973

City: New York, NY

Quantity: 53,005,000

Printed By: Bureau of Engraving and Printing

Printing Method: Lithographed, engraved

Perforations:11

Color: Lilac and multicolored

Issued to commemorate the progress made in electronics, this stamp features Guglielmo Marconi's spark coil and spark gap, which enabled him to transmit across the Atlantic Ocean by wireless radio.