Hei
Jeg har fått svar fra Jac hos
http://www.jacmusic.com/ og
www.emissionlabs.com
Han skriver følgende om mesh plate:
"Reasons for using mesh is published in a very old paper by Philips Holland. They say the heat can get out better.
You can check with
http://www.triodedick.com he send it to me. Anyway, we observed the same thing, and found some more pro and contra. When mesh tubes are made right, you can get more heat out of it than with solid plates. This is an advantage for that kind of tube with relatively high power filaments. Like rectifiers.
However you can't make the mesh very thick, and we found heat conduction is not as good as with solid plate.
That limits the above statements to relatively small tubes only.
In very old triodes you see mesh also with round plates, like the 227 for instance is almost always a mesh tube. Round plates form very easily and nicely when you use mesh. But it is only seen for small signal tubes.
With power tubes, we found there are specific problems which come in with audio tubes but not with rectifiers. We havebeen dealing with that and learning over the years, and we have found good ways to make mesh triodes, recently up to 28 Watt for the new 300B mesh, which is a real break though. We may specify the same tube higher, but we want to take no risk with it now. Mesh stays delicate technology . Note, the Chinese make "fools" mesh, which is no mesh at all. It is only punched plate. That can do full power, but it doesn't have the magic sound real wire plates have. I mean that fails the reason why you want mesh from audiophile view."
Så det nye han bringer på banen er at det muligens handler om at varmen slipper lettere vekk.
Skal maile triodedick også.
Asbjørn
