Complex sentence: Under the above convention the tube was redesignated 6P3S (Russian: 6П3С) and the 6V6 tube became 6P6S (Russian: 6П6С), Many specialised Russian tubes, such as special military or transmitting tubes, do not follow the above convention.
Split into simpler sentences: Under the above convention the tube was redesignated 6P3S (Russian: 6П3С). However, many specialised Russian tubes, such as special military or transmitter tubes, do not follow the above convention.