Well, It turns out the tube is ok after all. I have 2 Admirals that have the 7JP4 tubes. I have only ever had a B&K 466 tester that has worked well on all the other tubes I've have. I came across a Sencore CR-70 that looks like it has never even been used. Knowing it is one of the few testers that can test a 7JP4, I hooked it up. Both tubes showed the exact same symptoms, HK shorts and almost no emission. Not knowing any better, I thought they were in fact both bad. I got side tracked with other things, then I thought I'd give it another shot. I retest some known good tubes, first a 12LP4 then a 10BP4. These both showed strong on my B&K, but they show the same symptoms: HK shorts and low emissions. So now bells go off in my head, hey it has to be the tester. I did the CR-70 Field Test with my Fluke 189 and everything is fine. Hmm, I removed the screws and pulled the "guts" of the Sencore out. Looking for obvious signs of internal trauma and pushing down on ribbon cables to re-seat them. Then I spy one ribbon cable way in the back with about 6 wires on it. It had a slight "cock" to it. Pushing it down to re-seat it and reinstalling the "guts" back into the case. I retested the tubes, and all is well now. No, HK shorts and the emissions are way up in the GREEN. The one 7JP4 tests strong on all settings.The other one tests good on all settings except the cutoff which only came up to the 1 mark. I tried the Auto Restore function twice with no improvement in cutoff. It has lots of "meter swing" dropping the Bias one setting from -68 volts to -52 volts. So hopefully it can be improved. I didn't want to hit it any harder without trying it first. The 12LP4 and 10BP4 also test good. I didn't think my new Sencore "toy" would be faulty when I just acquired it. Maybe that's why it looks and smells new.
Tony