Ericsson ETL

©  Tube Collection Udo Radtke,
Germany  2010- 02-20

Ericsson Telephone (ETL, ETELCO, British Ericsson), was founded by LM Ericsson of Sweden, but became a separate company. LM Ericsson still exists, and is known worldwide mostly for its cell phones.

British Ericsson (ETELCO) was swallowed up in a succession of mergers, and is now a part of Siemens. Of course they stopped making tubes, including these, many decades ago.

They manufactured a lot of Dekatron types.

These are all cold-cathode (no filament) neon gas filled counting tubes, often referred to as "dekatrons" (also spelled "decatron"). They perform a complete divide-by-ten count function, all in one tube ! Something that would not be replicated until semiconductor ICs came along, much later. Like most dekatrons, the GC10/2P is a bi-directional (up/down) counter, achieved by sending pulses out-of-phase to the "guide" electrodes. These tubes became obsolete when semiconductor logic prices dropped in the late 60's, making dekatrons no longer competitive.

The GC10/2P is a very rare Dekatron, counting tube made by . Its a 2-guide, double-pulse dekatron, like the GC10B, 6802, and GS10C tubes, but crammed into a small 7-pin miniature package. Unlike its larger cousins (GC10B ...), its even harder to find. The, more common, GC10B comes in a octal package, and is the size of an EL34, while this GC10/2P is the same size of small 12AV6 and very rare. Not to many of these were made since the part number is hand written on the box. The GC10B, on the other hand had its number printed on the box, just like any normal tube.