Nick, Here is some information which does not match the GI-21 but atleast shows that the "SM-C-2092" number is used for other parts in the US military, http://www.wbparts.com/nsndetail.cfm?NIIN=006429929 - this also shows that the 5960 number is used for these parts, although I did not find any reference in the public lists.
The numbers on the box resembled those I use to find on old moving coil panel meters so I did a quick search and found this similar information above. I hope it can help you in some small part to hunt for more information. /Martin On 18 Nov, 10:48, Nick <[email protected]> wrote: > On Nov 18, 7:32 am, Accutron <[email protected]> wrote: > > > The Martin Company was an aircraft manufacturer - the same Martin that > > would end up as part of Lockheed Martin. They also produced missiles > > and other military stuff. The tubes are probably replacement parts for > > a Martin aircraft display, or were possibly used as part of the > > Project Vanguard rocket program, which was going on in the late 1950s. > > > Do the boxes have a USAF contract number? The contract number would > > provide a base of origin and you might be able to find out the exact > > program. > > Just found a box of GI-21s, NIB. They are dated 5/60 or 6/60 and have > a label which reads: > > 5960-552-0265 > ELECTRON TUBE > 1 EACH ITEM 1-2498 > 7901-PP-60-54-54-GFP > THE MARTIN COMPANY > GI-21 P/N SM-C-209280-1 > EXPORT PACKING AND CRATING Co., INC. > A IIIX 6/60 > > The end of the box is printed (not on a lable, on the box itself) > with: > > NU > GI-21 > MADE IN U.S.A. > > The digits are stacked (looking from the top) 0,9,8,7,6,5,4,3,2,1 > > There is no anode as all unused digits are used as anodes by means of > tying them each high with a high value resistor (typically 330K) and > then pulling the digit you wish to light low. > > The advantage of this is that no anode mesh is required, so no patent > infringement. Downside is the need for 9 extra resistors (10 needed > vs. 1 if you have a single anode). The GI-10 patent, #2,769,939 - > Charles R Williams, Northrop Aircraft Inc., (granted) November 6th > 1956 (application) June 12th 1950 covers this well... Interestingly, a > major claim of this patent is that the current draw of the tube is > substantially reduced (to about 1mA). > > Nick -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
