Screen current, straighten me out

[eschertron]

Very difficult for someone like me. The old data sheets, from 50's, 60's, have tons of data. The new data sheets, e.g. from JJ, are 1/2 sheet.

At least JJ puts out next to no data on their tubes to avoid (presumably in good faith) putting out unverified or unreliable data

[catalin gramada]

Very difficult for someone like me. The old data sheets, from 50's, 60's, have tons of data. The new data sheets, e.g. from JJ, are 1/2 sheet.

The big dangers for screen are arcing and power dissipation. Thanks God guitar amps design use limiters and we get something we can use. From a pentode design point screens voltages are not supposed to fly up and down around. The screens voltage is supposed to be as consistent as can be done and from this reason it was fixed a max admissible value in respect with max current screens can draw.

[Helmholtz]

Very difficult for someone like me. The old data sheets, from 50's, 60's, have tons of data.

The original datasheets are still available. Tubes carrying the same designation have to be compatible. A new 6L6-GC that doesn't meet the original spec. simply is no 6L6-GC.

What I meant is, look for the example that is closest to your application and use plate idle current/dissipation percentage specified as guideline. This avoids guessing if dissipation limits are specified according to design center or design max ratings.

The new data sheets, e.g. from JJ, are 1/2 sheet.

Such incomplete datasheets are a shame and make me wonder if the manufacturer really understands his product or if he is simply not able/willing to guarantee essential data.


BTW, big volume customers often compose their own component specs and make their suppliers sign them.