Just wondering if anyone has played with the 6CL5 sweep tube much?
Data on them is scarce.
I was thinking of using a pair with a 3.5Kohm (plate-to-plate) output transformer,B+ maybe around 400Volts,will probably keep the screens ~175V or so.
Does 3.5K seem like a reasonable impedance for these guys?
Any other thoughts?
Thanks!
Data on them is scarce.
I was thinking of using a pair with a 3.5Kohm (plate-to-plate) output transformer,B+ maybe around 400Volts,will probably keep the screens ~175V or so.
Does 3.5K seem like a reasonable impedance for these guys?
Any other thoughts?
Thanks!
Gah! No plate curves for those anywhere, eh?
What I do in a situation like that is run them to *just* visible distortion on the scope and make a note on the power output.
By adjusting the load resistance, make notes for 2K to 8K in 500 ohm increments (a good OPT is needed for this with lots of primary inductance.... I use a Pioneer OPT that's 8K:8R for tests).
There will be an impedance that gives maximum output.
If you want to get picky, you can repeat the steps only at 1 watt instead of maximum out and make a note of the Z that gives lowest THD and place the operating impedance in between the two
I'm lazy, so I do step 1 for max output and just add 20% and call it a day
Cheers!
What I do in a situation like that is run them to *just* visible distortion on the scope and make a note on the power output.
By adjusting the load resistance, make notes for 2K to 8K in 500 ohm increments (a good OPT is needed for this with lots of primary inductance.... I use a Pioneer OPT that's 8K:8R for tests).
There will be an impedance that gives maximum output.
If you want to get picky, you can repeat the steps only at 1 watt instead of maximum out and make a note of the Z that gives lowest THD and place the operating impedance in between the two
I'm lazy, so I do step 1 for max output and just add 20% and call it a day
Cheers!
Geek said:Gah! No plate curves for those anywhere, eh?
What I do in a situation like that is run them to *just* visible distortion on the scope and make a note on the power output.
By adjusting the load resistance, make notes for 2K to 8K in 500 ohm increments (a good OPT is needed for this with lots of primary inductance.... I use a Pioneer OPT that's 8K:8R for tests).
There will be an impedance that gives maximum output.
If you want to get picky, you can repeat the steps only at 1 watt instead of maximum out and make a note of the Z that gives lowest THD and place the operating impedance in between the two
I'm lazy, so I do step 1 for max output and just add 20% and call it a day
Cheers!
hey Geek,
Your last step, adding 20% to the load with pentodes is perhaps going the wrong direction. I'd go to max power and subtract 20%( numerically) to make the load line steeper. For Triodes, you've got a reasonable method...
cheers,
Douglas
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