This is the Rolls Royce of the 1930s radiogram era. McMurdo was an American company and sets were made in the UK under licence by the British McMurdo Radio Company. The set had more valves than you could shake a stick at. HF amplification and BFO for the 3 short wave bands made the set an excellent radio receiver. Two 6V6GT pentodes produced about 11 watts of audio, sent to a large 12" HT energised speaker. The set is quite capable of loosening the glass in your leaded lights.