sentences:  However, in practice, and particularly in the early years of the system's service, the performance of the reeds proved to be worse than had been expected.The TXE2-specific equipment was different in the TXE2s manufactured by Plessey, STC and GEC, so that spare equipment had to be held for each type of manufacturer.Importantly, each manufacturer made their own reed inserts (reed were manufactured for GEC by their subsidiary, the Mazda Osram Valve Company) and their performance differed significantly in the first years of production.