chaztaylor
New Member
Im testing a kt66 tube the mu on the roll chart says 6300 . If the tube I test tests at 6300 is that a min reading or a strong new tube reading for mutual conductance.
Thank you
Thank you
Easy hickok tube tester ? need help fast
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chaztaylor
New Member
Its a 532 model. I read the manual several times there is no example it just says average mu on the roll chart and in the book with no real explanation. So if test at or above that number it is considered a new or new used tube.below it is considered used is this correct.
Thanks
Thanks
chaztaylor
New Member
Thank you I have been trying to find info to this ? And been unsuccessful
jaymanaa
RIP 1961-2018
First thing is, you / we need to know if this "old" machine has been properly refreshed, and calibrated. You can use it, and get very useful info from them as found 8 out of 10 times probably, but if you want to know the most about the tube, and have accurate info, you need to have a properly calibrated machine. Just like a volt meter will tell you lots of info even if it's incorrect or close but not perfect. This is another good thing about tubes versus SS components, tubes are very forgiving to the the average guy that wants to work on gear as a hobby. A tube will work well in less than perfect conditions surrounding it, while SS devices are more fragile, and "picky" about things like voltage and current limitations. Now that's not saying SS device data sheets are the Bible, or the absolute last word on what they will do, just that tubes are very forgiving to the audiophile hobbyist.
Most Hickoks in that series, say the 600, 800 or whatever, have an "English" setting dial / knob. The roll sheet will give you a setting for that dial, say 50. If you set that dial to 50 and test the tube, you have a good / bad tester. If the tester is not calibrated this is probably the way to go. The roll sheet will also give you a mho (ohm backwards) number, say 5000. If you want exact data for a particular tube, you would set the English knob to the first higher number, which on my 800 is 6000. There are little red dots on the dial by these "scale" numbers. When you set that dial to 6000, or the 6000 red dot, then you have a tester that will tell you exactly what the tube will do (remember, it's needs to be calibrated to be accurate if it hasn't been calibrated in the last few years). Anyway, now you have the testers English knob set to the 6000 scale. Look at the meter movement and you will see a 0 to 6000 scale. When you push the merit button (usually 4 for pentodes like the 6L6 or 3 for diodes) take the reading from the 0 to 6000 scale. Don't worry about the good or bad, and green or red indicators, they don't mean anything, and the tube would probably look weak or bad. But if the roll says 6000 or 5000 or whatever, for the 6L6, that would be the number for a new tube. On my 800, the number for a 6L6 IIRC is 5000, so if I'm boxing up tubes, I will write the tubes reading (say 4700), then under that number I will draw a line, and write what a new tubes would be, 5000. So I end up with 4700 over 5000 on the box, or on the tube, or both, so when I go back to that tube, 6 months or 6 years later, I know what I have. Take a tube like the 12AX7 (good example), on my tester I think the roll says 1250 on each triode for a new tube, but a 12AX7 will function fine in an amp at readings waaaaay below that. What I really want to see in most cases, is the triodes testing similar. I don't want a 12AX7 where one triode test 1200 and the other tests at 850. I'd rather have one where both sections test 850 or 900, if that makes sense. Tube testers are strange tools, and you almost need to develope a relationship with your tester, and you will over time. An aside; when I built my 2A3 I used parts of an Asian circuit that uses a 6DJ8 as a driver for the 2A3, but it only uses one section of this dual triode, the other section isn't connected at the the socket. This way, I can use tubes in it, that would otherwise be worthless pretty much. I use the Triode 1 in the left channel and the right uses triode 2. So tubes with one bad triode, which are cheap, work fine, which gives me the opportunity to use gold pin SQ or PQ tubes that I really couldn't afford if they had good matched triodes. This is just one of many examples of how the tester can be used to save you money and bring you good audio. Sorry for the long post, just trying to be clear.
Most Hickoks in that series, say the 600, 800 or whatever, have an "English" setting dial / knob. The roll sheet will give you a setting for that dial, say 50. If you set that dial to 50 and test the tube, you have a good / bad tester. If the tester is not calibrated this is probably the way to go. The roll sheet will also give you a mho (ohm backwards) number, say 5000. If you want exact data for a particular tube, you would set the English knob to the first higher number, which on my 800 is 6000. There are little red dots on the dial by these "scale" numbers. When you set that dial to 6000, or the 6000 red dot, then you have a tester that will tell you exactly what the tube will do (remember, it's needs to be calibrated to be accurate if it hasn't been calibrated in the last few years). Anyway, now you have the testers English knob set to the 6000 scale. Look at the meter movement and you will see a 0 to 6000 scale. When you push the merit button (usually 4 for pentodes like the 6L6 or 3 for diodes) take the reading from the 0 to 6000 scale. Don't worry about the good or bad, and green or red indicators, they don't mean anything, and the tube would probably look weak or bad. But if the roll says 6000 or 5000 or whatever, for the 6L6, that would be the number for a new tube. On my 800, the number for a 6L6 IIRC is 5000, so if I'm boxing up tubes, I will write the tubes reading (say 4700), then under that number I will draw a line, and write what a new tubes would be, 5000. So I end up with 4700 over 5000 on the box, or on the tube, or both, so when I go back to that tube, 6 months or 6 years later, I know what I have. Take a tube like the 12AX7 (good example), on my tester I think the roll says 1250 on each triode for a new tube, but a 12AX7 will function fine in an amp at readings waaaaay below that. What I really want to see in most cases, is the triodes testing similar. I don't want a 12AX7 where one triode test 1200 and the other tests at 850. I'd rather have one where both sections test 850 or 900, if that makes sense. Tube testers are strange tools, and you almost need to develope a relationship with your tester, and you will over time. An aside; when I built my 2A3 I used parts of an Asian circuit that uses a 6DJ8 as a driver for the 2A3, but it only uses one section of this dual triode, the other section isn't connected at the the socket. This way, I can use tubes in it, that would otherwise be worthless pretty much. I use the Triode 1 in the left channel and the right uses triode 2. So tubes with one bad triode, which are cheap, work fine, which gives me the opportunity to use gold pin SQ or PQ tubes that I really couldn't afford if they had good matched triodes. This is just one of many examples of how the tester can be used to save you money and bring you good audio. Sorry for the long post, just trying to be clear.
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chaztaylor
New Member
The machine is not calibrated to my knowledge.from the information I have read and videos I have watched you can have two calibrated machines and the information they give you can vary about 20 percent. So from my understanding there inaccurate machines to begin with and dont take the info as the bible just use it to give you a good idea about the life of the tube. Most people selling tubes will tell you the info Is just a example of there tube tester. Also you stated the number on the roll chart for mutual conductance is for a new tube. The other person said it was a minimum value of a new tube. I want to know if thats the min number for a good tube or is that on the high side for a new tube. Let say the value is 5000 what is a strong new tube. What is a used tube. What is no good tube and so on. Thanks again
chaztaylor
New Member
Ok so that number is just a general brand new tube number. So if it test higher than that number it is a strong tube. That makes sence. Thanks