Roytron was another Triad spinoff! It is printed right on the Roytron box eamples I have found that states "Manufactured by Triad Manufaturing Company, Pawtucket RI.
On February 28th, 1929, Triad filed a trademark for the Roytron logo for vacuum tubes produced under that name.
Roytron tradmark record
Official Gazette Of The
United States Patent Office
Volume 393 April 1930