The EZ81 / 6CA7 / EZ90 Rectifiers

More small scale rectifiers. The EZ81 by RFT, a 6CA4 by NEC and an EZ90 from Daystrom. The EZ81 and 6CA4 are the same tube, EZ81 being the European designation. Spec sheets for the EZ81/6CA4 can be found here: here. and for the EZ90: here.