Sentence:  Upon close tickler coupling, the detector tube will oscillate, in which condition the tuning of DX will be faciliated. At such times the amount of energy radiated from the antenna is negligible, and does not interfere with reception or neighboring devices. This Roberts set is, therefore, "not" a "<WSD>blooper</WSD>." 
Meaning of the word marked with <WSD> tags:  A radio which interferes with other radios, causing them to bloop (squeal loudly). (from 1926)