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#1
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EL34 tube problem on HICKOK 539B tube tester!!
Hi:
I have one Mullard EL34 tube. I test it on my HICKOK 539B tester. I turn the tester power on after 1-2 minutes the micromhos meter is read on 5600. But test after power on approximately 6-7 minutes the micromhos meter indicator is reverse and turn the BIAS VOLTS VR is no function. I test other EL34 tubes have no any problem on the 539B tester. Does the Mullard el34 or the tester have any problem ? Please help me to close the problem. Thanks and Regards!! |
#2
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Hi,
I have one Mullard EL34 tube. I test it on my HICKOK 539B tester. I turn the tester power on after 1-2 minutes the micromhos meter is read on 5600. But test after power on approximately 6-7 minutes the micromhos meter indicator is reverse and turn the BIAS VOLTS VR is no function. I test other EL34 tubes have no any problem on the 539B tester. Does the Mullard el34 or the tester have any problem ? Sounds as if your EL34 has grid emission, and it takes a few minutes for the grid to heat up. It is contaminated with material from the cathode. Alan |
#3
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Alan Douglas adouglasatgis.net wrote in message . ..
Sounds as if your EL34 has grid emission, and it takes a few minutes for the grid to heat up. It is contaminated with material from the cathode. Alan Hi: The means the Mullard el34 tube is bad can not work on the Amp? Thanks! |
#4
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Hi,
Sounds as if your EL34 has grid emission, and it takes a few minutes for the grid to heat up. It is contaminated with material from the cathode. The means the Mullard el34 tube is bad can not work on the Amp? Yes. If the tube has grid emission, it will work for a few minutes but then the plate will glow red, as the grid bias goes positive and the tube draws too much plate current. Alan |
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