View Full Version : What kind of tube is this?

Mike Caldwell
10-14-2003, 06:23 PM
Just wondering if anyone has seen a tube like the one pictured here.
My guess is that is some sort of a display tube, maybe neon in nature as it has no filiment that I can see but it is no where
near as complex as a "nixie" display tube.

In a diamond shaped logo there are the letters GR and the part number 1538-1 there may have been another number after the 1
but I can't make it out.
Under that number is the number 7405.
If any one has any ideas let me know.

Mike Caldwell

11-06-2003, 05:16 PM
hi Mike -
likely some sort of UHF/VHF radar tube from the looks of it. Perhaps something like WE 316A or something. Check www.duncanamps.com - good tube data sheet locator there.


11-09-2003, 07:16 PM
For cool info on all manner of display tubes, from Nixies to extremely complex adaptations of TV camera tubes used to make mathematical computations,

GR was General Radio Corp., later renamed GENRAD. They used to manufacture some of the finest test equipment and calibration standards gear.
GENRAD was bought by TERADYNE Corp., makers of high-end ATE (Automated Test Equipment. TERADYNE have recently, by huge populat demand, brought back some of the classic GR gear such as decade resistors, decade caps, and the superb Strobotach. GR developed and patented the first VARIACS, "VARIAC" being a GR copyright. GR made the finest metered VARIACS for testing and lab use, with built-in (output voltage, output current, or volt-ampere) meters, Any combination of the meters was available. AC volts out metered types were the most common. Those with Volts out/Amps out/ & VA out metering were fairly rare, and very, very pricey. For example, a 1960's-made GR 10 amp VARIAC with a 0-140 VAC and a dual range, switch selectable 0-2 Amp / 0-10 amp meter can still fetch over $450.
http://www-2.cs.cmu.edu/~ram/electro/gr/ [IMG]http://www-2.cs.cmu.edu/~ram/electro/gr/grlogo.jpg

Mike Caldwell
11-10-2003, 04:49 AM
Thanks everyone for the the information!
The GR logo is just like the one on the tube.

Thanks again
Mike Caldwell