Very much On Topic: Integrated Vacuum Tubes

21 Apr 2005

...
   - What was/is
the smallest tube? purpose?   
 RCA's Nuvistor - a family often found in late 1960s TV tuners and some
 test equipments. They are almost always triodes, and are really small -
 3/4 inch long, maybe 3/8 inch diameter, all metal. RCA made a few half
 sized Nuvistors, but never sold them. 
Somewhere I have a valved hearing aid. It's a flat case that fits in your 
pocket containing a 3-stage amplifier. The first 2 stages use DF64s -- 
rectangular cross-section valves perhaps 1/4" wide, 3/16" thick, and 1" 
long, the output stage is a DL64 which is perhaps 1+1/4" long. They have 
5 lead-out wires coming from one end of the device, they could be 
soldered in, but here they're pluged into ting 5-pin sockets (I've seen 
similar xockets with 2 contacts not fitted used a transistor holders). 

There were also cylindrical valves, not much larger, on an 8-wire base.

-tony

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

Very much On Topic: Integrated Vacuum Tubes