01-22-2018, 04:22 PM
I just took a very quick look...7H7 is a semiremote-cutoff pentode, while a 6SK7 is a remote-cutoff pentode. A 6SG7 (semiremote-cutoff pentode) would be closer to a 7H7. The characteristics are not exactly the same but might be close enough for Gubmint work.
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Ron Ramirez
Ferdinand IN