Murray multiplex tape transmitter, made by the Reid Brothers, Camden, London, England, 1910-1920.

The Murray Multiplex transmitter was used with the Murray keyboard perforator. The tape output from the perforator was fed into the transmitter via a loop. If the loop shortened significantly, it pulled down an arm and stopped the transmitter until the operator caught up. Consequently the operator could maintain a natural typing speed without affecting other operators working into the same line.