You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
BBC_Television

Context:
Initially, the station's range was officially a 40 kilometres radius of the Alexandra Palace transmitter—in practice, however, transmissions could be picked up a good deal further away, and on one occasion in 1938 were picked up by engineers at RCA in New York, who were experimenting with a British television set.

Question:
What did the RCA employees use in order to receive the BBC signal?

a British television set