Establecimientos Castilla, S.A.E.; General Pardiñas 5; Madrid; Apartado 243.

Fabricación de receptores y válvulas.

In the 20s Castilla builds tubes like TA1, TA0 called "Piro-Micro". Also beginning February 1926 the TA2 as Superaudion. From then on, they produce US-types (brand "Superaudion") and transmitting tubes from 10 to 1000 Watts. See "Radios von gestern" page 229.