For Sale: very rare W-41187 Auto Expressionator tube. $95 + postage. This is an extremely rare tube that goes into the output stage a few 1930s Crosley round-dial console radios and in theory works as a “sound expander” to colorize the sound. Good continuity, tight base, polished pins. Try to find another one! This is the only one I have ever owned in 18+ years in the radio collecting hobby.
W-41187 Auto Expressionator Tube
Discolored getter flashing (brown or black marks) does not mean that a tube was used. This fiction is believed by both uninformed buyers and seasoned tube jockeys. This myth seems credible because some new tubes have perfect shiny mirror getter flashing; therefore the assumption is that brown or black stains in the getter flashing must indicate a used tube. The myth says that the more brown/black discoloration, the “more used” the tube is. Wrong.
Excerpt from Electronics Magazine
The purpose of the tube getter and flashing is to remove gas inside the tube envelope during manufacture. This discoloration myth can be quickly debunked by reading the article in Electronics magazine, October 1950, entitled “Getter Materials For Electron Tubes”. The article explains that if the getter is vaporized very slowly during the manufacturing process, “the first barium atoms evaporated will absorb the gas present so that the remaining getter is deposited in a very high vacuum, exhibiting a shiny mirror.” If the getter was flashed very rapidly during manufacturing, then “the getter mirror will be discolored due to the dispersion of the barium.” The article then explains that the discoloration “does not mean that the getter is contaminated, but merely that the deposit is finely divided and therefore absorbs light.”
I have taken a numbers of photos to demonstrate this myth, and also provide photos that demonstrate how the flashing looks when a tube is actually used. Let us proceed…
For Sale: $600 for this LOT of 6 Telefunken 12AX7 ECC83 17mm Long Smooth Plates Tubes, Made in Germany. Used, but Top Quality. All test excellent, very close to new. Characteristics of all six tubes: Made in Germany, Diamond bases, Long 17mm perfectly smooth plates, Top round getter, the first five tubes have “4 ribs on top of glass envelope”; the sixth tube (diamond base code 12,2) has a smooth top glass envelope, there is no silkscreening left on any of the tubes, new white boxes will be supplied for professionalism, and each box will be labeled and test scores recorded.
Test results (diamond base code is provided in parenthesis):
For Sale: Sylvania #50 engraved-base Audio Triode tube, TESTS NEW. Truly a beautiful tube, Made in USA, Sylvania engraved-base, ST-glass, Black Plate, clear-top, large solid square getter. Nice and clean, shiny flashing, shiny pins, no visible plate wear. Awesome.
Tested perfect new test score, scoring 1550 micromhos on the true micromhos scale with calibrated Hickok 6000 tube tester (a score of 1500+ is perfect new), and also without shorts or leakage. For those of you without a true micromhos scale, it tests very strong into the “Green-Good” range. Truly a top-quality audio triode. $280.
For Sale - Sylvania 50 triode tube
Here is a rare tube — a Marathon MX-280 Globe #80 rectifier tube featuring MESH PLATES construction! Not only that, but each section tests very strong Emission, comparable to an NOS #80!
In 18 years of collecting, I do not remember ever seeing another Mesh Plates #80 tube. Look at that Glow! You can see right through the Mesh Plates into the filament! This would be a beautiful tube for any serious collector. You could really impress your friends with this one.
Today I listed for auction on eBay© a very rare NOS Westinghouse RJ-550 Globe Triode Tube. This was part of my collection for long time.
RJ-550 is a low-grid-current triode amplifier tube. 2.5V filament @920mA, plate voltage (max) 220.
In 18 years of collecting, I have never seen another one.
This article provides examples of NATIONAL UNION-manufactured tubes.
NATIONAL UNION was another quality USA tube manufacturer with most production dating from 1930s to 1950s. Their production numbers were significantly smaller than the big name brands (RCA, Sylvania, GE).
The NATIONAL UNION (EIA) code number is “247″. Here is an example:
This post provides examples of Raytheon manufactured tubes.
Raytheon was an extremely high quality USA tube manufacturer with prolific output, covering both civilian issue and a vast majority of US Military parts production. The Raytheon (EIA) code number is “280″.
Here is an example:
This article provides examples of GE (KEN-RAD) manufactured tubes.
GE was one of the most prolific tube manufacturers in US history, and many companies sold GE tubes repackaged under their own brand name. The GE factory EIA code number is “188″ and proves GE was the true manufacturer. Here are several examples:
This article provides examples of RCA-manufactured tubes.
RCA is probably the most famous tube manufacturer in US history, and many other companies sold RCA tubes repackaged under their own brand name. The RCA (EIA) code number is “274″ and proves RCA was the true manufacturer. Here are several examples:
