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Frank
USA
39 Posts |
 Posted - 10/09/2013 : 18:24:40
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| Just got my put together GMC-080 and ordered a 4011 tube, I see some postings out there for voltages, so with all the ones I came across, and not knowing what the unit was tested at and type of tube fro testing it, what is a good voltage to set it too for a M4011 tube? I would assume looking down at the adjustment, that turner it clockwise will increase the voltage, and CCW would lower the voltage? does anyone know what they are set for approx when it arrives without a tube and what is a good voltage for this tube, can I measure at the tube contacts? Thanks, want to get this up and running.. |
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| Reply #1
ZLM
1261 Posts |
Posted - 10/10/2013 : 09:38:35
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The M4011 tube works good with 280V~380V. You can CCW the voltage port to the lowest voltage.
If you want a accurate voltage on output, you need to do a measurment with a high resistance resistor and then do the calculation.
see:
http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=3745 |
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| Reply #2
Frank
USA
39 Posts |
Posted - 10/10/2013 : 15:11:33
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| Ok, I measured across the clips without the tube and got 275. Wasn't sure if it was measured with and without the tube in place. I just wanted to get a ballpark range so I didn't pop the tube. I will check on the link too. Thank you |
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| Reply #3
Frank
USA
39 Posts |
Posted - 10/10/2013 : 18:25:57
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| Hum, the pot seems to be turned as far as it goes and voltage measured at the tube ends, powered up is 275V, am I safe there with the 4011 tube? seems to be the lowest the adjustment will go.. looking down at it, turning one way it went higher. Not sure now, but I think its maxed at CW direction and when I went to go CCW with it, the voltage increased to 300.. need to look more tomorrow at it... |
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| Reply #4
ZLM
1261 Posts |
Posted - 10/12/2013 : 14:39:05
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Not sure what kind of multimeter you are using. But 275V (directly measured) is in a high range of working voltage for M4011. Try to bring down little bit. If this is the lowest voltage you can get, then just keep it and let unit to run for some times. If the background reading is stable, then it should be OK.
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| Reply #5
Frank
USA
39 Posts |
Posted - 10/15/2013 : 16:38:10
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| Ya, the pots are set all the way CW so I kept them there because it seemed (lowest voltage) that if I turned it CCW, the voltage increased. Ya, its a bit confusing, working voltages are this range, but need to set it too this range. |
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| Reply #6
Frank
USA
39 Posts |
Posted - 10/15/2013 : 16:43:53
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| Just found the specs for my DVM, 20meg ohms input impedance. |
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GMC-080 and tubes
