FW version 0.98 (build 20250215) SPIFFS:20241231

Latest firmware:
  • Latest Software
  • Changelog for ESP32 version
  • Changelog and uTracerJS
  • Features:
  • supports uTracer’s .utd and .uts files
  • acquires measurements up to the specified ‘Power max’ value
  • interactive manipulate with Load Lines
  • generates LTSpice tube models
  • displays curves in a window or full screen
  • compares up to 4 sets of curves at the same time
  • automatically corrects of anode and screen voltage sagging during Quick Tests
  • Links:
  • ESP32-uTracer website
  • uTracer main website
  • ESP32-uTracer in Google Groups
  • Screencasts how to use the tool:
  • Youtube Channel
  • Acquire data
  • Acquire data 2
  • Load lines
  • LTSpice modeling
  • Changing tube socket colors
  • Backing up and restoring files
  • Changing colors for uTracer/Tube pins
  • How to do quick test with specified Ia, estimating the corresponding Vg and Gm
  • Acknowledgements:
  • Ronald Dekker (uTracer, Lab Notebook)
  • Derk Reefman (SPICE modeling PDFs)
  • Christophe (Generator of parameter strings)
  • David Hanslip and Martin Manning for extensive tests and help with debugging)
  • Joe Curcio for ideas for QuickTest types #3 and #4
  • All the users for testing and providing feedback!
  • Description of parameters
    | Home | Acquire |
    Voltage Correction if checked, stores the actually measured Va and Vs in .utd file (also shows those values in the legend), otherwise the set in the user interface values for Va and Vs are saved
    Double Acqusition this option improves the accuracy of Va and Vs measurements. During the acquisition pulse, the Va and Vs voltages are sagging for about 5-10 percent, because of the currents that flow through the sensing resistors. With this option On, uTracer will do two measurements, first one to estimate the voltage sag and then to reapply a bit higher voltage so that the measured Va and Vs will be exactly as specified by the user. The acquisition time does not change (and for sure does not double) because those are two shotr measurement pulses almost at the same operation point.
    Delay [sec] specifies the delay that will be applied between the measurements (the Va Vs and Vg will be constantly applied for the specified period of time. This option is required for calibration of uTracer and can also be used for re-formating of electrolytic capacitors (as described here)
    Logging to file if checked, stores the measurements in a file on the ESP32 file system (see Files>.utd)
    Pmax defines max. power (Ia * Va), after which uTracer will not try to acquire measurements. 0 means no constrains
    | Quick Test |
    adjust Va/Vs Adjsut the specified Va and Vs during the quicktest, compensating loosing voltage drops due to capacitor discharge, so the measured Va and Vs are equal to Center Va and Vs
    Set as Default It is possible to load a configuration and set it as 'default'. Then after the reboot, that configuration will be automatically loaded. If there is no defautl config set, the last used configuration (applied during the quick test) will be loaded after reboot.


    Type: --
    Heater Voltage: -- [V]
    Heater Current: -- [A]
    Max Power: -- [W]
    Search for tube data

    Connection diagram (tube socket pin numbers):

    A G G2 G3 C H1 H2
    uTracer outputs:
    Grid Cathode Screen Anode Heater
    G
    C
    S
    A
    H
    Background color
    Foreground color


    Make connections between the same colors

    In practice notation might differ, for example:
    • S (screen) is typically denoted as G2
    • G3 for pentodes is typically connected to cathode C
    • Ab, Gb and Cb correspond to the second half of dubble-triodes

    Only indirectly heated tubes are properly visualized, for connection of directly heated triode and rectifiers see Testing Directly Heated Tubes