The uTracer, a miniature Tube Curve Tracer / Tester.

The table below lists the most important characteristics of the uTracerNXT and uTracer6
and compares them to the now obsolete uTracer3+

Characteristic:	uTracer3+	uTracerNXT	uTracer6
Status	Obsolete	Now available!	Now available!
Anode and screen supplies	Voltage range: 2 to 400 V Current range: 0 to 200 mA	Voltage range: 2 to 500 V Current range: 0 to 350 mA The maximum current can be increased to 1A, see “My-uTracerNXT”	Voltage range: 2 to 1000 V Current range: 0 to 1 A
Grid supply	Voltage range: -50 V to 0 V	Voltage range: -120 V to 0 V	Voltage range: -100 V to 0 V An extension board (grid shield) is available that extends the grid bias range to positive grid biases 0 V to +100 V, including grid current measurement 0 – 100 mA.
Internal heater supply	Voltage range 0 – 19.5 V (max. 1.5A) The heater supply PWM modulates the supply voltage at a frequency of 19.5 kHz. Due to this relatively high PWM frequency parasitic inductances in the leads will result in a lower effective heater voltage. For this reason, many users prefer to use an external heater supply.	Voltage range 0 – 19.5 V (max. 1.5A) Compared to the uTracer3 the PWM frequency has been reduced to 1.2 kHz. This makes the effective heater voltage virtually insensitive to parasitic wiring inductances, resulting in more accurate heater voltages.	Voltage range 0 – 19.5 V (max. 1.5A) Compared to the uTracer3 the PWM frequency has been reduced to 1.2 kHz. This makes the effective heater voltage virtually insensitive to parasitic wiring inductances, resulting in more accurate heater voltages.
AC heater supply supported?	No .	An AC heater supply (transformer) for directly (and indirectly) heated tubes is standard supported. Read more	AC heater supply for directly heated tubes is possible with a small (user made) additional circuit. Read more
Extensions, Options, Personalization	There is an extensive set of modifications and options for t the uTracer3+ available (see next FAQ). However, they are all add-on circuits that users must make themselves. .	Extensive possibilities to personalize the tradeoff between ranges and resolution have been directly incorporated into the design of the uTracerNXT, e.g. for higher currents, more accurate grid voltages or low anode/screen voltages for battery tubes. Read more in the “My-uTracerNXT” guide.	There is an extension board (shield) available for the uTracer6 that allows for positive grid biases (0 – 100 V) and the measurement of grid current (0 – 100 mA). Read more
Maturity	With more than 2700 uTracer3 units in operation in over 64 countries, the uTracer3 was a successful and well debugged kit. The experiences with the uTracer3 provided valuable input for the development of the uTracer6 and uTracerNXT	The newcomer uTracerNXT builds on the extensive experience gained with the uTracer3+ and uTracer6. At the updating of this page more than a hundred uTracerNXT have been shipped to first customers, and many have reported their uTracer working as expected.	More than 580 uTracer6 units have been constructed without significant problems.
Application range	The uTracer3+ was primarily intended for low/medium power tubes used in the driving stages of amplifiers, radio’s, and televisions.	The uTracerNXT covers the applications range of the uTracer3+, but with its higher voltage and current range and control grid voltage range down to -120 V, it now also covers power (audio)amplifier tubes.	Although the uTracer6 can also test and trace low power tubes, its application range are primarily medium and high- power tubes such as encountered in audio output stages and RF transmitters. Especially the possibility of positive grid voltages (including grid current measurement) will be appreciated by ham-radio enthusiasts.
Robustness	Overall, the uTracer3+ has proven to be a robust design. Nevertheless, points for improvement are: The pnp based HV switches The negative power supply based on an inverting boost converter with a pnp switch	The uTracerNXT uses basically the same robust circuit topologies as the uTracer6 for the negative power supply and the HV switches. An additional advantage is the use of more readily available and serviceable SMD MOS transistors.	In contrast to the uTracer3, the uTracer6 uses MOSFET transistors in both the negative power supplies as well as in the HV switches. In practice these circuits have proven to be very robust!
User interface	The graphical user interface (GUI) is primarily a Windows application, although many people have it running on other platforms using a Windows emulator program like Wine. Ihor Smal has written an excellent alternative GUI in Java Script, uTracerJS, that I fully support. It runs from your internet browser and is fully operating system independent. Both GUI’s are free of charge.
Price:	Not applicable	€239 by international bank transfer (IBAN) €255 by PayPal	€329 by international bank transfer (IBAN) €350 by PayPal
Conditions of sale	Price includes: shipment worldwide and assistance with construction including mail support and physical debugging of the unit if needed in incidental cases. PCB with SMD components assembled, all other components (difficult to identify components in labeled bags), and a printed and bounded manual. Not included are: USB to serial cable, 19.5 supply (old laptop power supply), tube sockets etc.