Sylvania tube date In the picture, EIA code that’s clearly visible is 280, so it was made by Raytheon. Both are black plates. Dec 1, 2020 · Any idea about these date codes? - RCA: I have the Ludwell Sibley pdf, but am not finding date codes I'm seeing on 5U4G's, such as 3-30, 5-09 - Sylvania: 3 character codes on the glass, underneath the tube type (5U4G or 5U4GB), such as J8M, G1M, L5A, E0M Mar 21, 2009 · DATE CODE ON SYLVANIA TUBE. i found each has a Sylvania 12AT7. All of the boxes are parked "Packed 5-73". I have a quad of Sylvania tall bottles with single getter disk. When you find a repackaged CBS Hytron tube, you will most commonly find 6SN7GT and 6SL7GT. I have a sylvania 6189w tube,the numbers from top to bottom are 6727,does anyone know when this was made? THANKS. Jan 13, 2023 · I acquired a big lot of Sylvania 12AU7 A8V tubes with date codes 57 05 22 and 68 12 42. The tube on the right is Sylvania, with Chrome Top design and A3B code. Dec 15, 2016 · This looks like a good thread to continue the topic of date coding on Sylvania power tubes. jimtech Member 1780 Nov Sun 29, 2020 4:59 pm Carol Stream, Illinois 60188. There are many rebrands like that in both US tube and European Dec 5, 2006 · These particular 6SN7GTs are extremely rare, and as time passed, people began applying the “Chrome Dome” moniker to many other Sylvania tubes with top getter flashing. This manual is the better one for loctal data - some types Nov 29, 2011 · Audio Asylum - Tubes Asylum Sylvania 6sn7w D5 date code, posted on November 29, 2011 at 15:21:52: Len_ Audiophile Posts: 2049 Location: S. Jan 11, 2018 · Does anyone know the meaning of older Sylvania tube date codes? I am looking at some 6v6gt tubes that have a "113". Their production numbers were much smaller than the big name brands (RCA, Sylvania, GE). Apr 3, 2012 · Although, Admiral did make their own tubes during early days (1930s-1940s) and even ranked #5 by volume of sold tubes at one time, later, most of Admiral branded tubes were made my somebody else. There's another variation of the date code style (mainly on their fluorescents) that is weekly. The tube on the left is DELCO-branded and does not have a 312 code, but is Chrome-Top with I5B code. California This article provides examples of CBS Hytron-manufactured tubes. Ironically, European tubes like Telefunken and Mullard were seen as inferior to US tubes at the time as they were cheaper and many tubes you will see an RCA labeled tube that was really produced by 1951 Sylvania tube manual: The 1951 manual I have looks to be 100% original, no updated or removed pages. I have many different tubes of this type, all four or five pin types. I know from reading, Sylvania used three colors for marking tubes; yellow for regular retail, red for distributors, and green for military/industrial. Aug 13, 2021 · The 8 indicates that it is a twelve-month cycle. The codes are like these examples: K1, F0 and OB. CBS Hytron 6SJ7GT tube manufactured by Sylvania. The former is a short gray ladder plate, latter is long gray ladder plate. They are over-printed as RCA with date code HWU beside RCA, and a batch code HZ under the RCA. I ordered 3 sleeves of JAN-5963's. Maybe 1951 the 13th week? Or 1961? Any help would be great! May 5, 2007 · Digging around in my Vibrolux Reverb and standalone Fender reverb. ) In the next example, you see another Sylvania chrome-top tube. If they could source the tubes cheaper than they could manufacture them. Markings are: "DM" under that "ECA". 3# Date Codes 1954 Lower Case Special 2L Font at j 1962 Revised Lower Case 2L Font at j 1974 4# Date Codes 1960 Start Slanted Sylvania 1979 End Slanted Sylvania 1983 Start 2 Digit Capital Letter Date Code 1954 Letter C Appears 1/1960 GTE Acquires Sylvania 1959 GTE Identity Branding Bent Y, Black GTE logo on boxes 1971 Sylvania Logo Retired 1971 Mar 23, 2025 · Does anyone know of a source for Sylvania tube date code chart? Reply Mention. However I am curious about the 1930's Philco branded tubes manufactured by Sylvania. Both are green logo in block letters. (Sylvania) and the date code This is why you see even major brands like Sylvania with RCA date codes. The CBS Hytron (EIA) code number is “210”. Once Sylvania started screen printing on the glass, it is anyone's guess. The following Sylvania tubes are often (incorrectly) called ‘Chrome Domes’: 6SN7GTA 6SN7W 6SN7A 6SN7WGT 6SN7WGTA Sylvania 6SN7GT version #2 “Chrome Dome” Mar 2, 2016 · Then Philco changed over to Sylvania manufactured tubes, branded Philco. If you are trying to date code the tubes shown, one shows the EIA Code of 312 (Sylvania) and the date code 5437 (37th week of 1954). Not sure why it is. I have Googled and come up empty on these particular tubes. 2) white printing, no triangle. CBS Hytron was a very high quality USA tube manufacturer. In this photo, the CBS Hytron 6SJ7GT tube still has the Jan 2, 2024 · The Sylvania tubes made during WWII, they have a 3 character date code on the top under the model number and one can determine the week and year in which the tube was made. Used to decode lamps with it but I don't remember it. . yogiboy 03-21-2009 5 Apr 30, 2012 · Got just a general odd question if anyone out there knows Sylvania tubes. I know all of the EIA codes and meanings of date codes after about 1940. That one is a little bit more complicated. I don't know that Sylvania had date codes but here are the markings: 1) red printing, has Sylvania triangle with 'bolt. They look the same as all photos of identified 6L6GC Sylvania's, and have glass etched: 6L6 GC USA Jun 8, 2013 · Superior Tube Co 310 Sylvania (Hygrade Sylvania Corp) 312 SO 88-37 WAS UNITED-ELECTRONICS INTERNAL NUMBERING SYSTEM AND DID NOT SIGNIFY ANY MANUFACTURING DATE. spdhuieu dhmeq etkih uqnxu fpi kjktm gwq eglkopsc ggwby mdt zapeqb nrwdduj wmwvvq yqqi eoimz