From: "Geoffrey G. Rochat"
Subject: Re: Digital divide by ten, 1949 style
Date: Sun, 15 Sep 2002 21:56:09 -0400
Organization: Sprint Advanced Network Services
References: <3D84D4B3.50B511EF@webaccess.net> <3D850A3C.31381AD5@webaccess.net> <3D852DB5.2AEB8909@webaccess.net>
NNTP-Posting-Date: Mon, 16 Sep 2002 01:41:11 +0000 (UTC)
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>5 volts hung on until the end in rectifiers. Correct me if I suffer
>poor memory but didn't all of the 866, 872 and 575 tubes have 5 volt
>filaments? These, of course were in power applications.
No, 866, 866A, 866AX and 866 Jr. tubes were hefty half-wave mercury
vapor rectifiers with 2.5V filaments. The 866B had a 5V filament, as
did the 872. I don't know about the 575. 5V filaments were usually
found in garden-variety full-wave rectifiers such as the 5BC3, 5R4, 5U4
and 5Y3, although 6.3V filament full-wave rectifier tubes such as the
6AX5 and 6X4 were not uncommon. Most 6.3V rectifiers, however, were
half-wave horizontal damper tubes such as the 6CL3. And, of course, the
35W4 found in many AA5 radios had a 35V filament with a filament tap
intended to drive a #47 incandescent pilot lamp.
Data for all these types and more may be found at
among other places.
Other venerable electronic counting technologies are Dekatron tubes and
beam switching tubes, information on which can be found at Mike's