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Old 8th February 2013, 09:30 AM   #161
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Ok so this testcard I made doesn't seem to be right, I read the manual and checked all the pins and it did make sense and I honestly thought it would work.

However after heating up a tube for a short time some smoke came from the tester, I quickly removed the tube and re-did the card and tried again with same result.

Maybe someone can tell me what's the flaw in this test card? Hope I didn't really destroy anything in the tester... seems to still work though.
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Old 8th February 2013, 10:01 AM   #162
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neeevermind I found what I did wrong ha ha ha, I must have been sleeping..
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Old 8th February 2013, 10:02 AM   #163
cerker is offline cerker  Germany
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There was for some reason no connection made for grid No. 1 (No plug)! Should have been plug 44/I. Which version of my software were you using, I want to try to reproduce that, the latest snapshot sets the connection for G1 properly.

Therefore, when heated up the tube may have drawn way to much plate current (because of Ug1=0V) and overloaded the supplies by that. Since that are tube regulators, the damage to them should be limited, but maybe some of the (unfortunately) custom shunts are damaged. I recommend to check that.

I'm sorry for that unfortunate outcome, but I thank you a lot for taking the risk of alphatesting.
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Old 8th February 2013, 10:05 AM   #164
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ohh.. good you found out... you was missing negativ voltage on G1
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Old 8th February 2013, 10:41 AM   #165
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Yes I don't know what happened, I was sure I had it set right but having a 2nd look it now works just fine!
I think I was just so busy checking that everything that was there was configured right that I forgot to check for what was missing

Would there be any reason why my tester seems to indicate lower than it should for S reading on all tubes? (it has always done that, it didn't just happen now after this incident.)

For example it seems to give S reading of about 3-4 when it should be showing 5.5'ish and more. Seems to be more exaggerated on tubes with higher ma/v, for example new 1625 reads 4'ish and should be 6'ish. So it's a good 25% low.

Cerker, I don't think your software did anything wrong, I might have just not clicked it properly when I was using the scroll menu, sometimes scroll menus are like that. Alternatively, could it reset itself if you change the other items later? It was the first one, the one with the save picture error.

I have to say I am very happy that you made this software it's fantastic that someone would do this.

Last edited by Eivind_E; 8th February 2013 at 10:49 AM.
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Old 8th February 2013, 11:23 AM   #166
cerker is offline cerker  Germany
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Quote:
Originally Posted by Eivind_E View Post
Would there be any reason why my tester seems to indicate lower than it should for S reading on all tubes? (it has always done that, it didn't just happen now after this incident.)

For example it seems to give S reading of about 3-4 when it should be showing 5.5'ish and more. Seems to be more exaggerated on tubes with higher ma/v, for example new 1625 reads 4'ish and should be 6'ish. So it's a good 25% low.
Where do you take your reference values from. Are they from the datasheet for exactly this operating point?

I ask because "simpler" transconductance testers tend to show higher than real values, because they don't filter out hum and harmonics, as the L3-3 does. Actually, it measures the transconductance EXACTLY according to its mathematical definition, especially because it eliminates the ac plate voltage in the power supply (the plate voltage sense divider is connected after the plate shunt resistor).

Since the calibration routine puts a tap from the range divider directly to the selective amplifier, errors both in the oscillator and amplifier (and measuring instrument) are effectively compensated. Critical is the range divider and the plate shunt resistor, because the calibration relies on them as precision reference resistors. So one of those should be bad, I think.

Quote:
Originally Posted by Eivind_E View Post
Cerker, I don't think your software did anything wrong, I might have just not clicked it properly when I was using the scroll menu, sometimes scroll menus are like that. Alternatively, could it reset itself if you change the other items later? It was the first one, the one with the save picture error.
That can happen if you change the tube socket after doing some settings. When a special connection is not available at this socket, it will get reset. Nothing should happen if you "fill out the form" from top to bottom.

But your incident showed to me that I should think of implementing some sort of sanity checking, e.G. if all grids are connected and warn the user if thats not the case. I will keep that in mind for later versions.

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Originally Posted by Eivind_E View Post
I have to say I am very happy that you made this software it's fantastic that someone would do this.
Thanks, I hope it will help many people.
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Old 8th February 2013, 07:46 PM   #167
cerker is offline cerker  Germany
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I just uploaded a snapshot which should automatically use English language on English systems. Please try it out, I need to know if that works. If it does, there will be a new alpha release.

Greetings,
Christian
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Old 11th February 2013, 10:33 AM   #168
cerker is offline cerker  Germany
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UPDATE: In all former snapshots, attempting to test a direct heater rectifier will lead to shortcircuits!

Therefore, in newest snapshot direct heating is disabled for rectifiers until this problem is fixed.
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Old 11th February 2013, 01:49 PM   #169
cerker is offline cerker  Germany
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I just did an attempt to fix that problem, now there are 2 additional pin functions available:

Heater(+) & Cathode
Heater(-) & Cathode

NEVER assign both of them, that will short circuit the transformer!


The next alpha release will have some sanity checking, which forbids to do that. But at first you can check with a few cards if it works basically correct.
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Old 14th December 2013, 07:45 PM   #170
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have there been any further updates to the program?
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