Description

The GC12/4B is a counting tube oddity: a 'dekatron' that is designed to count in base-12 instead of base-10. Base-12 tubes served an important niche function, since the hour of the day is typically measured in 12 or 24 positions, they allowed designers to save an entire tube in any device that measured the time of day.

The GC12/4B is a 4kHz bidirectional counter with a neon fill gas, and is in every way identical to a GC10/4B with the exception of six extra cathodes in the counting loop, to allow for a divide-by-12 function to be carried out in a single tube.

The explosion in popularity of nixie clocks and similar devices has made these tubes rather hard to get, as they are hotly contested in the open market by hobbyists for use as hours indicators in dekatron-based clocks.

ETL GC12/4B Datasheet (PDF)

More

Hivac GC12/4B dekatron tube in operation. As yet we do not have an ETL-manufactured example of this device.


This top-down photo shows the six extra cathodes needed to perform a base-12 count.

 Return to Dekatron Glow Transfer Counting Tubes