I have recently built a uTracer6 and noted a measurement accuracy issue using Ronald's GUI.
If you do a sweep with the (Va=Vs,Vg) the GUI seems to incorrectly report the test voltage for the screen current being measured.
The result can be large errors in the data collected for any (Va=Vs, Vg) sweep that involves a large test current delta between the anode and screen ports.
This is most notable at lower test voltages and high test currents.
For example if a high current pentode is measured in triode mode (think sweep tube) where a large delta is present between a high anode current and the screen current there can be a significant discrepancy in the test voltages used for the actual measurement and what voltage is reported by the GUI.
This can under some condition result in large errors in reported results.
To confirm this I measured a 50 ohm resistor on the anode port and then on the screen port.
With Ronald's GUI testing a 50 ohm resistor on the anode port and taking the reported test voltages and currents from the GUI, calculation confirms a 50 resistor is being measured.
Repeat this with the screen port and the GUI results suggest in error a 100 ohm resistor is being measured.
Note this seems to not be a defect with the uTracer6 hardware or firmware but only seems to be a issue with the present GUI.
I confirmed this by remeasuring the 50 ohm test resistor using the utMax GUI and then for both anode and screen ports the GUI returned the correct voltages and currents for a 50 ohm test resistor.
At this point I do not know if any other test modes other than (Va=Vs,Vg) on Ronald's GUI are affected on the uTracer6.
I have had a uTracer3+ for many years and not noticed this issue with the uTracer3+.
I do however use a older GUI version with my uTracer3+ than the latest version I am using with the uTracer6.
As well the uTracer3+ can not measure the high currents that a uTracer6 can and I only see this issue at higher currents on the uTracer6.
If you do a sweep with the (Va=Vs,Vg) the GUI seems to incorrectly report the test voltage for the screen current being measured.
The result can be large errors in the data collected for any (Va=Vs, Vg) sweep that involves a large test current delta between the anode and screen ports.
This is most notable at lower test voltages and high test currents.
For example if a high current pentode is measured in triode mode (think sweep tube) where a large delta is present between a high anode current and the screen current there can be a significant discrepancy in the test voltages used for the actual measurement and what voltage is reported by the GUI.
This can under some condition result in large errors in reported results.
To confirm this I measured a 50 ohm resistor on the anode port and then on the screen port.
With Ronald's GUI testing a 50 ohm resistor on the anode port and taking the reported test voltages and currents from the GUI, calculation confirms a 50 resistor is being measured.
Repeat this with the screen port and the GUI results suggest in error a 100 ohm resistor is being measured.
Note this seems to not be a defect with the uTracer6 hardware or firmware but only seems to be a issue with the present GUI.
I confirmed this by remeasuring the 50 ohm test resistor using the utMax GUI and then for both anode and screen ports the GUI returned the correct voltages and currents for a 50 ohm test resistor.
At this point I do not know if any other test modes other than (Va=Vs,Vg) on Ronald's GUI are affected on the uTracer6.
I have had a uTracer3+ for many years and not noticed this issue with the uTracer3+.
I do however use a older GUI version with my uTracer3+ than the latest version I am using with the uTracer6.
As well the uTracer3+ can not measure the high currents that a uTracer6 can and I only see this issue at higher currents on the uTracer6.
