Last updated: 14-Jan-2018 22:28->

Create set up files for EML tubes

The database the AT1000 uses in the computer mode, is a file called tubedata.csv, in the install directory of the AT1000. This is a so called ASCI file, or Comma Separated File (csv), which is the same. It which can be edited by hand, when your really know what you are doing. Always make a backup first before you even touch it, and better look at the copy. If you change only a point or a comma in the wrong way, the file may become corrupted for the AT1000. (not corrupted as such). So never open this file with Excel, because when you save or autosave it by mistake, Microsoft will hide as a minimum your initials inside the file. If so, the file is corrupted. I do not recommend it to others, but myself I use open office, and that works fine. To add EML tubes which are not included, there is the "tube edit" program from Amplitrex.

Alternative to editing the tubedata.csv file, there the option to leave this file unchanged, and use a "set up" File, which method no risk on mistakes. The set up file is based on a specific tube, but final testing is done with another set of data, which is be stored at a personal file on your PC. This is how to do it:

  1. Boot the tester in the computer mode and start the "tube test" program.
  2. To test a 300B alike tube, first call the 300B tube by entering: 300B. This will initially select all 300B data.
  3. Suppose we want to create a 300B-XLS set up from this.
  4. Click the "set up" button and save the screen first now as "300B-XLS". Use an intelligent location to save. Though this is set by default, better is not use the amplitrex program folder. Reason is, when you re-install the Amplitex program, all your set ups are lost. So better create your own folder for this, like call it C:/data/myamplitrex/setups/ or any other easy to find location you can create.
  5. After this is done: Re load the set up file you just made, and see if it works. So it was named 300B-XLS, but when you select it, all data is from 300B still.
  6. Now click the button "Test Setup", and change all data to 300B-XLS data. The 300B-XLS data is to be taken from the TUBE BOX. So Anode voltage, Anode current, Control Grid Voltage and transconductance.
  7. After this is done, cLick the button "Limits", and add the limits for the 300B-XLS, that is 60 Watt dissipation, and 120mA.
  8. Click the "curves" tab, and enter following data there: Number of curves 9. Anode start 75. Anode max 495. Anode step 10. Ug Start 5. Ug step 15. This will plot 9 nice curves, and chart scaling etc is good.
  9. Then click "Setup", and "Save", and now this set up can be loaded any time conveniently.
  10. For this, click "Setup", "Open", and select "300B-XLS" from your own directory.
  11. The above was just preparation.
  12. Now testing begins. Click the button "Function" and choose only "noise test"
  13. Switch on the heater and wait one minute.
  14. Press "Start" to start the test.
  15. The following is not shown on the PC, but only in the AT1000 green display. Observe how the tube is biasing now at 120mA. Observe all of the time carefully what happens, and stop the test when the current becomes more than 110%. If so, immediately restart the noise test afterwards, and you will see it will stays more stabile at 100...110%. In case is still exceeds 110%, restart again.
  16. After 5 minutes, stop the noise test. Careful with the tube now, the glass is very hot.
  17. Without waiting now, de select the noise test button, select "tube test" and press "Start".
  18. Now the tube is tested with hot anode.
  19. When the test is finished, Anode current should be same as on the tube box. What is actually tested is now, was -Ug and Gm, and this should be compared with the box data.
  20. Optional, now tube curves can also be plotted. In case you get funny triangles instead of curves, it can be solved like this.

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