uTracer6 Tube Curve Tracer
A while back I decided I needed a curve tracer (everyone does). I landed on a website from the Netherlands run by Ronald and Marie-José. After a bit of research, the uTracer 6 kit showed up on my doorstep. I took the time to carefully construct it, calibrate it, and put it into a nice enclosure. I had a 16x8x3" Hammond steel chassis in stock here, so that was the base of my design. The nice thing about the uTracer is you get to make the enclosure just the way you want it. I wanted to keep it simple and neat and include the 4 tube sockets that we tend to use 95 percent of the time. We can use adapters for the rest when needed. I went with the jumper wire design to connect the tube pins to the uTracer like Ronald did on his own unit and only used good-quality Johnson/Cinch banana sockets and plugs. I added a generic 5A buck-boost converter to run larger filament tubes over 1.5A and it surprisingly has a very clean output on the scope, The uTracer is limited to 1.5A heater current itself, which still covers a majority of tubes. To stop any unwanted oscillations, I installed many ferrite beads throughout the wiring and kept all the tube socket leads about the same length like in an AVO tester. All the wire used is overkill rubber 5000V 18AWG test lead wire. My goal was to keep the underside as clean as the top and make it easy to get the board in and out for any future modifications. The uTracer is powered from a laptop power supply. The one I used was rated for 5A. I included a 330uH inductor in the DC+ line heading into the board, and both the heater and power are fused accordingly. Also, a fused IEC socket is used for the mains power in. So far, I have had very good results with no sign of any oscillations during testing and very accurate results that match the tube data sheets very closely. We will now be able to match tubes very accurately! All in all, this was an excellent project to build and will be put into constant use now that it’s done. For more information on the uTracer, here is the link to Ronald's website.
UPDATE: We purchased the positive grid voltage extension board kit for our uTracer, This allows us to curve trace tubes running the grid voltage above 0 volts like in a class AB2 amplifier. We are excited to try this out on some transmitting tubes.
https://www.dos4ever.com/uTracer3/uTracer3_pag0.html
You get a bag of organized parts and an almost blank PCB
NOS 6P14P-K (soviet EL-84) compared to the published Philips data, as you can see the uTracer is very accurate!
Below is a closer look
NOS 6SN7
used EL-84 tube
new Psvane EL-34C
very tired KT-88
NOS soviet 6P14P-K matching the philips data sheet very well
NOS soviet 6P1P-EV