[BC] DeForest and pure vacuum, nothing about Kahn

[COURYHOUSE at aol.com]

I know that.
 
just trying to  say a 200a  or an 00A  is  soft tube
 
201a or 01a  is hard vacuum  ( or a 301a... (we know it is a mfr prefix)
 
the soft one  in the  20s also was  thought to  sill be better as a detector
 
In a message dated 6/29/2012 7:33:17 A.M. US Mountain Standard Time, rcarpen at comcast.net writes:

>> NO  LOOK   OOA  AND O1A   SAME AS 200A  AND 201A  0 HAD GAS  O1 HAD HARD VAC

>The first digit of 3-digit tube type numbers indicated the manufacturer,