Jul 16, 2015 · An actual crack in a valve's glass envelope, ie such that its vacuum and so ability to function fails, will have a very obvious consequence on the appearance of the getter flash, ie it will turn white, see photo 4 thetubestore - Blue Glow in Tubes, Tube Getters, and other Info Beginner Introduction Guide to Tubes & Valves in Amps Nov 19, 2018 · If it still doesnt glow with a tube you know is ok, then it may be amp tech time. Is the Getter White? This one is an easy diagnosis. The getter is the silver coating at the top of the tube which absorbs gasses so it doesnt interfere with the functioning of the tube. If the getter is white, then the tube isnt operating in a vacuum
There is a very wide range, where absolutely good tubes will have a blue FLUORESCENT glow, and they're perfect products in every respect. This not to be confused with a gassy tube of course. This is what Western Electric says about it:"A blue glow may appear in the dome of the WE300B just below the upper mica and the top edge of the plate. Gas-filled tubesThis glow is normal and must not be confused with the glow present in high-vacuum tubes when gases are present. A high-vacuum tube with a bluish glow is gassy and should be replaced. The ionization of these gases will distort the output of the tube and may cause the tube to operate with much higher plate current than it can carry safely. Getters- why do some not "get it?" - Talkin' Tubes - The Dec 06, 2016 · The take home message seems, not to buy into all the claims on the color being emitted, the type of getter, etc. These are just characteristic of the tube type and material. A blue glow may be prettier than the orange but, the change in SQ is really based on the amp design/execution, tube
The Getter Flash absorbs gas molecules to maintain the tube's vacuum. If the Getter Flash turns from silver to ash white you know the tube has been contaminated with too much oxygen from a vacuum leak. Dual Triode Tube. The glowing hot tubes are the dual cathodes (this is a dual triode design). My tube is gassy Page 3 QRZ ForumsNov 17, 2012 · The Chinese 811A tubes have two getters; zirconium on the anode and a barium getter near the base. Barium getters are used in some transmitting tubes (glass and metal-ceramic) as well as Traveling Wave Tubes that do not use a vac-ion pump. A vac-ion pump is an electronic vacuum pump that pumps 100% of the time the tube is powered-up. Tube Question--blue/purple huecoming from 6L6'S The May 30, 2009 · The blue glow is simply some electrons hitting the glass. The higher the voltage & current flowing through the tube, the brighter the glow. This has always been the case with tubes, NOS or otherwise. It is perfectly normal and expected.