28th of February 2021 Shi-ichi from Japan reported his uTracer6 working, and his wife made a great compliment about the esthetics of the PCB!

Dear Ronald & Marie-José

Thank you for your mail.
I attach two photos with this mail, the uTracer6 PCB I constructed and tracing scene. Please use them freely.

Add to my last mail, three modifications are applied to PCB.
LA1 through LA4 RFI suppression beads are covered by insulating sleeve and they are mounted on paper phenol resin sheet.
To avoid careless touching is the reason. They are tall.
Values of parts in the grid bias trimming circuit are changed.
R45 2M7 to 390k
P40 100ohm to 500ohm
The adjustment range was slightly narrow for my PCB condition.
Probably 200 ohm trimmer and 1M ohm R45 is better. But I don't have 200 ohm trimmer in my parts box.
POWER led is changed to green one. Simply because I usually use GaP green led for power indicator.

At this time, tracing is done on a lunch tray. This style is comfortable for experiment.
Upper left unit is USB to serial converter with command display. This unit includes TX/RX isolator by means of two photo couplers, to eliminate large ground loop.
A 6J11 dual pentode compactron is the DUT.
Measured plot image is collaged on the tray.
I am very satisfied with this result. Thank you Ronald!
When I understand enough about operation of this nice device, I will start designing the enclosure for uTracer6.

Yesterday, I showed uTracer6 PCB to my wife.
She said to me, "Mr.Dekker has his own aesthetics, I can feel it. This board is beautiful".
She is a graphics designer. I wish my modifications do not spoil your board design.


20th of February 2021 Roger Whigham finished his beautiful uTracer within a few days, encased and all!

Hello Marie-José,

The kit went together very well. The instructions were clear and easy to follow. You and Ronald have done a great job putting this together. I really appreciate your effort.

I've attached some photos of the finished product. In case you're wondering, I built the chassis before I received the circuit kit. Although I've only tested a couple of 12AX7's, I haven't seen any oscillations yet. I'm keeping the snubber handy in case it is needed.

Thanks again for all your hard work.

Best regards,

19th of February 2021 Freddy from Germany is the first of the non-beta testers to report his uTracer6 working!

Hi Utracer v6 arrived today, I have assembled and calibrated, works great. I have tested RF Zero Bias Transmitting Triodes, Eimac 3-500Z Russian G811, American 811A , Cetron 572B , Svetlana 572B, and Chinese 572B up to 1 KV Anode and +120V Grid1 via screen Booster.

All measurements are equal to microtracer v3 biz only up to 400 volts and 600 mA current after modification. The next day I will test some audio tubes el 34 el 84 6l6 6p3s kt66 and some double triodes ecc 83 85 88 and Russian equivalent 6n1p 6n2p and 6p3s.

Thank you and have a nice day