The original German text page 231 reads

Inzwischen ist Besuch gekommen, zwei Funker, die freigebig zum Essen eingeladen werden. Sie sitzen im Wohnzimmer, wo ein Klavier steht.

The German word "Funker" means radio operator. (From the German word Funke for spark, funkeln = "to sparkle", etc. The funk morpheme was used in the vocabulary of the early 20th century development of radio, when the "spark gap radio" was the hot technology. It lives on in modern German in the words Funk = "radio", Rundfunk = "broadcast", funken = "to communicate by radio", etc. Cf. the English slang "Sparks" for a radio-man at sea.)

As several of the comments indicate, "wireless man" was used as an informal equivalent of "wireless operator" in the early part of the last century.

The original German text reads, on page 232 in the linked edition:

Inzwischen ist Besuch gekommen, zwei Funker, die freigebig zum Essen eingeladen werden. Sie sitzen im Wohnzimmer, wo ein Klavier steht.

The German word "Funker" means radio operator. (From the German word Funke for spark, funkeln = "to sparkle", etc. The funk morpheme was used in the vocabulary of the early 20th century development of radio, when the "spark gap radio" was the hot technology. It lives on in modern German in the words Funk = "radio", Rundfunk = "broadcast", funken = "to communicate by radio", etc. Cf. the English slang "Sparks" for a radio-man at sea.)

As several of the comments indicate, "wireless man" was used as an informal equivalent of "wireless operator" in the early part of the last century.

The original German text page 231 reads

Inzwischen ist Besuch gekommen, zwei Funker, die freigebig zum Essen eingeladen werden. Sie sitzen im Wohnzimmer, wo ein Klavier steht.

The German word "Funker" means radio operator. (From the German word Funke for spark, which was coined when the "spark gap radio" was the hot technology, and lives on in modern German in the word Rundfunk = "broadcast". Cf. the English slang "Sparks" for a radio-man at sea.)

As several of the comments indicate, "wireless-men" was used as an informal equivalent of "wireless operator" in the early part of the last century.

The original German text page 231 reads

Inzwischen ist Besuch gekommen, zwei Funker, die freigebig zum Essen eingeladen werden. Sie sitzen im Wohnzimmer, wo ein Klavier steht.

The German word "Funker" means radio operator. (From the German word Funke for spark, funkeln = "to sparkle", etc. The funk morpheme was used in the vocabulary of the early 20th century development of radio, when the "spark gap radio" was the hot technology. It lives on in modern German in the words Funk = "radio", Rundfunk = "broadcast", funken = "to communicate by radio", etc. Cf. the English slang "Sparks" for a radio-man at sea.)

As several of the comments indicate, "wireless man" was used as an informal equivalent of "wireless operator" in the early part of the last century.