On Tue, 20 Nov 2018 06:28:19 -0800 (PST), wrote:

On Tuesday, 20 November 2018 12:24:49 UTC, wrote:

On tube testers:

YES, they are handy if you have a good one that tests for shorts and gas. And if you are going "full audiophile", one that allows you to match is also useful. But the brute fact of the matter is that there are few testers out there that actually give information that is both good and useful. That a tube has no shorts and is not gassy is good to know, but not particularly indicative of its function-in-use. I keep two - one a fairly simple Simpson emissions tester, good for about 90% of my needs, and a Hickok 539B, which is allows proper matching with additional equipment (2 x VOM). Sadly, tube testers that have been restored, calibrated and are reliable are getting scarce and expensive. The amount of *stuff* that crosses my bench in a given year justifies the need.

I also keep a very good scope - that I have used twice in five years to find that niggling problem, and that was on solid-state devices. If I ever get another scope, it will be a "pocket" device as they take up a LOT of real-estate otherwise.

Peter Wieck
Melrose Park, PA

Maybe it's time to make some new tube testers.

While we're here, an iso won't help if you connect an earthed scope to the thing. It will bite you if you touch, and that's how HT is.


NT
See that's exactly the kind of advice that I can't be told often
enough. Even though I did already know about this. My isolated variac
does not have an isolted ground so I bought one of those plug/socket
adapters that doesn't pass the ground through but instead provides a
tab to connect to ground.
Thanks,
Eric