The uTracer Tube Tester / Curve Tracer

Tube-specific discussions

Moderators: CurtissRobin, colossal, zaphod_phil

Post Reply
User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 1984
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

The uTracer Tube Tester / Curve Tracer

Post by JMPGuitars »

If anybody is looking for a great (advanced) project, the uTracer Tube Tester / Curve Tracer is awesome. It has a quick test function that covers all the bases that most good tube testers might cover. Additionally, you can trace curves to see much more detailed specs about your tubes, as well as real tube matching. I've had mine for 2 years now, and I definitely recommend it.

If you're going to build this project, I recommend a few modifications to make it much better, and more accurate. Please also review the build instructions before purchasing this. It's not a good project for a beginner.




CONNECTIVITY
Here's some tips regarding connectivity if you don't want to use the serial port: Don't use the 5 capacitors, IC chip, or dip connector for the serial port.

For USB only connect the Ground, TX, and RX. When using a USB board, don't connect the USB board to the PIC 5V supply, it isn't needed (and might cause issues). For Bluetooth connect 5V, Ground, TX, and RX. Don't forget to adjust the voltage going to the BT board's RX port if it isn't 5V compatible. I did the LED trick to accomplish this.

Remember in both cases that the devices are communicating with each other so the TX from one device goes to the RX of the other and vice versa. If you connect TX to TX it won't work.

The trick to using both boards in mine is a simple switch that connects or disconnects the 5V supply to the Bluetooth board. Once the 5V is connected to the BT board, it overrides the USB board automatically.

Bluetooth may appear not to work in Windows. That's more likely Windows' fault than the hardware. Windows is annoying about this. You should first attempt to update the driver for the BT board. In most cases, Windows will install two COM ports for the BT board. Typically, the first (lower) port number is the number you need to use in the uTracer software. In Windows Device Manager, you may need to reduce the buffer size on that port before it will work.

Alternatively, you can test the connection with your phone, which is almost always easier to make a connection with than Windows. Once you've determined the hardware is okay, then go back to Windows and deal with that headache. ;)




EXTERNAL HEATER POWER SUPPLY
Today I added an external heater supply to my uTracer. This is what I used: https://amzn.to/31Iijhs - it was only about $36.

The thing is awesome! It has protection for over voltage/current/wattage, and it has memory settings to recall different setups. With this power supply you can always see the live voltage, current, and power when it’s on (also shows input voltage). It also has a power button to enable or disable the supply output.

There are some known issues with the uTracer's heater supply. With the external supply, the tests are much more accurate:

Here's an EF806S:
TungSol-EF806S-QT.jpg

Same tube with the external heater supply:
TungSol-EF806S-QT-EPS.jpg

I also think the thing looks pretty cool installed in my tester:
_JMP6155.jpg

I run my uTracer over bluetooth, and it was annoying before switching between tubes. I would have to restart the GUI every time after hitting Abort, and then sometimes I would have trouble reconnecting bluetooth too quickly. This completely solved that issue. Now I don't do anything to the GUI, and I only turn the heater supply output power button on and off between tubes.




uTracer POWER SUPPLY
The manual / website recommends using an old laptop power supply for this. I had no interest in that. Instead I build a dedicated, regulated 19V power supply using a Hammond 187E28 transformer, and a NJM2397F chip. I may decide to share the schematic for this at some point, but right now I'm keeping those docs private. ;) One tip though, if you want to make one yourself, use a 1.5A fuse and a 330uH inductor on the positive line.

Here's a peek at my power supply:
_JMP2108.jpg
Thanks,
Josh
You do not have the required permissions to view the files attached to this post.
2 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 1984
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: The uTracer Tube Tester / Curve Tracer

Post by JMPGuitars »

One other thing. If you read his site, you'll see there are a lot of different ways to wire the tube sockets. Mine are wired (from left to right) 1: 12AX7 etc.., 2: EF86, 3: EL84, 4: EL34, 6L6, 6v6 etc...

This covers almost everything I would likely ever test, but if I were to do it again, I might also add banana plugs hidden on the back to connect an external socket for other weird tubes.
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

User avatar
JMPGuitars
Super Duper Admin
Super Duper Admin
Posts: 1984
Joined: Tue 09/18/12 8:00 pm
Location: South Central, MA
Contact:

Re: The uTracer Tube Tester / Curve Tracer

Post by JMPGuitars »

I've added a couple more mods to my uTracer.

First, I added two additional inductors to speed up the boost converters. The "quick tests" are much faster now, and the traces have increased speed as well.

Second, I increased the current limits with a few additions suggested on the uTracer site. Now my tester goes up to at least 600mA.
0 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook · Instagram
Items for Sale

Post Reply