Round_Type-C

Towards the end of 1911, Harold J. Round of the Marconi Company designed diode valves but suspended his work until November 1912 when he also did some work on triodes. The first successful soft valves of Round were produced in 1913. The valve was probably influenced by the soft valve of von Lieben, Reisz and Strauss since there were some agreements between Marconi and Telefunken at that time. Type C was also used for a r.f. amplifier in direction finding equipment which went into service in 1914. This tube was madewith either E27 or B22 base. The grid and anode connections were from wire leads on the sideof the bulb.