What did those hard-won commercial radiotelegraph licenses look like? Many SOWP members donated theirs to the archives, so we’re able to show you the ones below.

Lindh 1RT License – This one belonged to Charlie Lindh, originally a Swedish sailor whom we’ve featured before.

Zerbe 1RT License – Lindh also signed off on another legendary early radioman, Ray Zerbe, as shown here.

Benson 1RT License – Ralph Benson agreed to adhere to requirements with this obligation “taken freely, without mental reservation or purpose of evasion” as documented here.

Maxwell 2RT License – Walter Maxwell, who reported to Radio Intelligence head George Sterling during WW II, has his second-class FCC license here.

Henry Mallory Station License – And here we have an example of a station license, this one for the Mackay station aboard the Henry Mallory in 1939. Damped wave emissions (spark transmitters) were well on their way out, but not completely gone, as you can see.