Tube Lab #12 How to Identify Tubes Made in North America

Tips on how to identify vacuum tubes made in the USA and Canada.
Link to Quality Vintage Tubes: valvesnmore.com
A big thank you to Tube Maze for the EIA codes!
tubemaze.info/eia-codes-to-id...

[@RRickenbacker]

These videos are great. Thanks for posting!

[@thomkopal1740]

Thank you for this video. You have the right idea of using all details of tube construction as clues to identifying tube manufacturing origins. EIA codes really help. So true - it is very important to not get distracted by painted labels; look inside the glass for the features you know are unique to certain manufacturers. Those clues include plate coatings, plate holes/folds/ridges/staples, and mica shapes, including holes and details of the edge shapes. Also consider features of the glass envelope - for example, mid-'50s Sylvania short-plate 12AX7 have unique elongated/pointed glass evacuation seals, and 12AX7A or 7025 made by Sonotone in their Elmsford NY factory had much smaller diameter and height glass envelopes (as well as unique white material insulating the wiring below the plates). Let's clear up two unfortunate InterWebz misunderstandings that get repeated too often: 1) Octagon/"stop sign" boxes around the tube type does NOT assure RCA manufacturing. Many, many North American tube manufacturers utilized that octagonal box (or elongated rectangular octagon, on miniature tubes). These manufacturers include Tung-Sol and Raytheon, as well as many others such as Sonotone, Ken-Rad (early GE) and Lansdale. 2) Etched dots on the glass does NOT necessarily indicate GE origin. Westinghouse and CBS also used etched dots on tubes they manufactured (caution: many "Westinghouse" tubes are re-branded, and manufactured by other companies. You cannot be *sure* if it is "Westinghouse"). GE used those dots as their proprietary date coding, so they could tell when their tubes were manufactured and decide to honor warranties or not. If you want to find out more about GE dot codes, search on GE date codes and you can find excellent information posted by Jim Cross.

[@marclacasse1]

Very helpful.

[@outboardfun3353]

You make good videos thanks

[@grimtale69]

Great video

[@eddieh5901]

Silvertone was a brand created and promoted by Sears for its line of consumer electronics and musical instruments from 1916 to 1972. Your Silvertone tube was rebranded for Sears.

[@tubelab194]

Thank You for filling in the history of this tube and the rebranding. Silverstone is a great brand name! It must of helped sell a lot of tubes for Sears and RCA!

[@frankgeeraerts6243]

GE code 188 = Owensbury plant....

[@tubelab194]

That must have been one of GE's main plants as I see lots of 188-xx coded tubes from GE. I see the plant is shuttered and they're trying to find a buyer. We need a factory space, but as much as I love Kentucky, I don't want to move that far.

[@frankgeeraerts6243]

The plant 188 in Owensboro originaly belonged to KEN-RAD = ( Kentucky Electrical lamp Company ) @@tubelab194