Tubes Asylum Questions about tubes and gear that glows. FAQ |
|
In Reply to: RE: Help identifying tubes posted by Stian01 on June 22, 2015 at 05:22:09:
Hi Stian01 The 27 is an indirectly heated fairly low mu triode. It has a Unipotential Cathode which is the way tube development was going. For a single triode it pulls huge heater current. The tubes you show are both
ST glass - meaning not globular nor tubular. Earlier examples of the 27 and 45 would be made with globular glass envelopes in the same fashion as incandescent light bulbs of the time - late 20's. Try consulting the book Tube Lore by Ludwell Sibley. 45 Power Triodes were made in the millions for the exponentially growing home radio market. I would peg the year of manufacture circa 1933. The 27 follows the 26 in many many ways - another great voltage amp. The 56 is a close cousin too. Have fun and Happy Listening!
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: Help identifying tubes - elektron 06/22/1509:48:47 06/22/15 (1)
- RE: Help identifying tubes - Stian01 00:05:03 06/23/15 (0)