Erick, K8LV, says:
>Despite its higher voltage and dissipation rating, this tube is identical to
>an 811A when operated in the 1-2KV plate voltage range. Many of the
>applications for this tube fall into this range - the familiar 1500-2000V
>4x811A desktop KW. My old 30L1 is exactly such a beast, and is what started
>this whole thing. Anyway, within that range the operating characteristics and
>interelectrode capacitances are virtually identical. Also, it is not possible
>to drive the tube hard enough to require that higher (160W) dissipation.
>Above about 600ma. the Gm starts to drop like a rock . Hence, my original
>statement that it quacks just like an 811A.
I see your point now, that at the 30L1 operating conditions, they two
triodes play almost the same. If you had a blank sheet of paper to
redesign and wanted to utilize the 572 for more whoopie like it could
make, you can do so. Crank up B+, and driver 'er harder. But
substituting them into a fixed design doesn't buy you anything.
The vacuum tube Tesla coilers used to put 572s in place of 811s for
more discharge, and push them until they were orange.
73
K5PRO
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