The last box to your right is identical to the first box of the ECG line. The tube in this box might be labeled Sylvania or Philips and may or may not say ECG. The two boxes in the middle are shown with the top flap up. Other than the flap, the design is identical except the older is flat while the newer is glossy. Writing color was usually yellow, occasionally red (sometimes the red appeared more like orange and is given as such in the tube lists), and more rarely green. If the tube writing was red, then the box flap tube type writing was usually red. If the tube writing was yellow or any other color, flap writing was usually black. The Sylvania tube writing scheme was similar to GE's method - see table below. Philips tubes that may come in the newest box are usually yellow, but occasionally are written in blue. The second box from your right is very similar to the one preceding it. Note however, the ECG Components on the bottom line. This is the box used for Solid State tube replacements such as the R-3A3 (ECG508).
Sylvania's EIA/RETMA code was 312, but they rarely used it. You'll see it more on other brands that Sylvania actually made. Date coding was a 2 letter code. Then a 3 letter code began to appear, while still having a separate 2 letter code. Originally, I thought the 3 letter code was a manufacturing plant code, while the 2 letter code was still the date code. Now, I'm not sure. More recently it seems the 2 letter code was more consistent, while the 3 letter code was more varied indicating the 3 code might now be the date and the 2 code the manufacturing plant. I need clarification on this. On some older tubes there was a one letter date code.
Below are two views of the same box. Sylvania Gold Brand were special high reliability tubes similar to GE's Five Star and RCA's Command series. Tube writing was gold and the pins were often gold-clad.
The type number was preceded by GB- (As in GB-5726).
TUBE WRITING COLOR TABLE:
|TUBE WRITING COLOR||BOX FLAP WRITING||MEANING|
|Yellow||Black||Standard Sylvania Warranty|
|Red/Orange||Red||Distributor Warranty Only|
Syl sells to dist for less
Sylvania absolved of warranty
|Green||Mil Box: Black|
Export Box: Unknown
|Military or Export|
No Standard Warranty
The above table applies only to the Yellow boxes. In the old Green box days, standard writing was usually green.|
The newer Philips/ECG tubes usually had blue writing.
|Ever wonder why SYLVANIA tubes were so good?||This article was re-printed in the September 1929 issue of RADIO BROADCAST, a magzine for retailers and servicers.|
Today it is tongue-in-cheek. Back then it was said with a straight face.
"FACTS ABOUT SYLVANIA TUBES||
IN A BOOKLET entitled Business Facts about Sylvania Radio Tubes, we find the following four reasons why the tubes identified by the "Flashing S on a Green Oak Leaf" are good tubes.
First: Sylvania precision operations are handled by men trained for years. And we never rush them, because if you crack a whip over skilled workers they become nothing more than laborers, and the product is bound to suffer.
Second: We will never let a Sylvania tube leave the factory unless it passes fifteen rigid inspections. That protects the product against rush and hurry because all tubes must pass those tests or go into the junk pile. And junk piles run into money.
Third: Sylvania has contentment. No slot machines are on Sylvania's payroll. Our hundreds of employees are treated like human beings, given good wages and every consideration, from a completely equipped hospital and nursing staff to buses that take them back and forth.
Fourth: Sylvania's up-to-the-minute plants at Emporium, Pennsylvania, are in the heart of the Allegheny Mountains where the air is crisp and healthful, bodies rugged, eyes clear, and minds alert."
A Story For Our Time|
A Tale of Courage and Grit ~ With a Twist
|A Rousing Adventure|
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