[ARC5] Old Navy Tube Numbers

[Roy Morgan]

Arc-5 folks,

A fellow in Canada has just got two RBC's and an RAB power supply.   
The schematic I find for the power supply
(at: http://www.skywaves.ar88.net/commrx/RCA/RAB/RAB_schematic.gif )
has the old navy numbers for tubes - I am guessing that 38180 means  
type 80 rectifier.

Is there a cross reference list of these old 1930's tube types?  My  
tube notes includes only this message on the topic (I just added the  
38180 entry):

Roy


Date: Mon, 14 Jul 2003 13:01:04 -0400
To: glowbugs <glowbugs at piobaire.mines.uidaho.edu>
From: "John M. Franke" <j.m.franke at larc.nasa.gov>
Subject: GB> 38XXX series tube numbers
Sender: owner-glowbugs at piobaire.mines.uidaho.edu

Those 38XXX series tube numbers.

While trying to get a US Navy military surplus RU-17 receiver working,  
I ran across some strange tube designations.  The final audio output  
tube is a 38233, which I had never heard of.  Searches for information  
seemed fruitless.  Then, scanning the manual for another US Navy  
military surplus receiver, a DZ-2, I saw a pattern.  The 1939 manual  
implied that the 38XXX system was a "Former Navy Type" designation.  I  
observed that the first two digits, 38, was used to designate the item  
as being a vacuum tube (see: http://www.designation-systems.net/usmilav/electronics.html#_EarlyNavy 
  orhttp://www.maritime.org/wish-mote.htm).  The last three digits are  
either the commercial tube designation or a coded version of the  
commercial designation.  If the first of the three digits is a "0",  
the following two digits are the commercial designation.  For example,  
a 38041 is the same as a type 41 vacuum tube and a 38076 is a type  
76.  For other tubes, like a 38636, the two sixes are retained and the  
second digit is replaced with the corresponding letter.  In this case,  
the third letter in the alphabet is a "C", so a type 38636 tube is  
actually a 6C6.  A 38646 is a 6D6 and so on.  A short list of tube  
numbers I have translated is presented below.  Of course, the system  
did not work for the specific tube I was seeking, but it does seem to  
work for others.  Is the alignment I discovered real or happenstance?   
Does anyone else have a clue or reference for the 38XXX numbering  
system?

38041		41
38076		76
38111A	        CW211C
38142		2C45, 45 Special
38145		845
38166		866
38180           80 rectifier most likely
38233		2C21/1642
38636		6C6
38646		6D6
38808		808

Sincerely,  John  WA4WDL


Roy Morgan
k1lky at earthlink.net
K1LKY Since 1958 - Keep 'em Glowing!