Question about the 6AR6 tube. I have some of these and my cheap Sencore tube tester says "emission and shorts test only". Why no leakage test? The tubes I have are used but when testing, they read good. If I do go to the leakage test anyway, they also read good. After about 10 minutes on the tester, the emission test drops very low and the leakage goes way up. Maybe the sencore can't handle the 1.2a filament draw? I have about a dozen that all test this way. My other cheap tester has no notes about that particular tube but only has a neon lamp for leakage. Will try them on it later. Also have a 177-b and will hook up the mx adapter to try and test, that model has a gas test.
They are not a rectifier tube, it's a beam pentode. I have a 6ar6 amp I built, if I run the tube there for 10 minutes, then place in the tester, it shows the low emission high leakage still. I can't see why you can't run a tube under test for 10 minutes unless the tester can't deliver the current for the filament.
Most Tube testers use rectified pulsating voltages. They do not use DC to test with. Because they use pulsating voltages, the bias is not stable. They are meant to perform momentary testing to give a basic indication of whether the tube is good or bad.
Every test set manual I have seen cautions against testing for longer than is necessary to get a reading.
Every test set manual I have seen cautions against testing for longer than is necessary to get a reading.
Well that is contrary to what I have read elsewhere. But, that is another subject all together. If I place the tube in the amp for 10 minutes, then move it to the tube tester, it reads low on emission and high on leakage. The original question was why does the tube tester say no leakage tests for this particular tube? Do you have any experience with the 6ar6/6098?
It's a TC154 Sencore. I'm testing them now on a 177-B and no shorts and they all test good. Plate currents are within 2 ma on a dozen tubes. For some reason when they are hot, the leakage goes up. Maybe the Sencore is more sensitive to that fact, as i know a lot of testers measure leakage in many different ways(values). In the amp i can let them idle (70% diss of 19w) for hours and no changes to any voltages or currents. For some reason the Sencore says no leakage test on that particular tube. Will swap in a few resistors on the octal socket and see what moves the meter.
I have read the 6146 and some other higher power tubes have grid emission or leakage due to the closeness of internal cathodes and grids (or something to that effect).
I have read the 6146 and some other higher power tubes have grid emission or leakage due to the closeness of internal cathodes and grids (or something to that effect).
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