Hagerman Technology LLC: VacuTrace

"VacuTrace" Vacuum Tube Curve Tracer (discontinued)

VacuTrace is a vacuum tube tester curve tracer instrument for the analysis, characterization and matching of vacuum tubes. It uses your existing analog oscilloscope as an X-Y display. Together, they form a complete stand-alone test station. The upgraded chassis forms its own carrying case for greater portability and protection when not in use. A second carrying case is included for adapter cards and cables.

VacuTrace was created for engineers and technicians who develop, manufacture and test vacuum tubes and circuits. It is designed to measure tube characteristics and present the information in the manner you've come to expect - a set of operating curves. Matching tubes has never been easier or more accurate; thanks to its novel A/B alternating sweep capability, which overlays the curves of two different tubes (or sections within a dual type) for the ultimate comparison. In addition to sweeping curves, measurements of voltage, current, transconductance gain and output conductance (1/rp) can be read on the 3.5 digit LED display.

Operation is simple and intuitive. There are no software, menu or boot delays to contend with as the circuitry is entirely analog and everything happens in real-time. Removable socket adapter cards accomodate the most popular tube pinouts. Blank adapter cards are available for customization. A optional "Jumper" adapter card is available for $249 that can wire up any 7, 8, or 9 pin tube.

The VacuTrace connects to any analog oscilloscope in X-Y mode. For a PC-based USB scope, which can save outputs as .jpg or print screens, there is the Stingray, which is the only scope of this type that has X-Y capability. And it's only $220. A good used Tek scope can be bought on eBay for under $100.

VacuTrace has received a number of reviews in the press. Actual customer testimonials.

VacuTrace

Example curves

Jumper card (optional)

Features

Generates characteristic curves for diodes, triodes and pentodes in real-time
Tests both small signal (12AX7, 6SN7) and power tubes (5Y3, KT88, 300B)
Performs matching, even on dual tubes
Sweeps to 400V plate, 200mA cathode, -70V grid and 40W power
All analog design with digital readout of voltages, current, transconductance gain and output conductance
Four socket adapter cards accommodate most popular tubes and pinouts
Uses oscilloscope (not included) as display
Overload protection on all outputs

Specifications

Plate Voltage	0V to 380V @ 200mA
Cathode Current	0mA to 100mA (200mA in 2A mode)
Grid Step Sizes	0.5V, 1V, 2V, 5V, 10V (8 steps) @ 5mA
Plate Power †	20W peak (40W in 2A mode)
Screen Voltage	100V to 300V @ 25mA
Transconductance	0.1mA/V to 20.0mA/V
Output Conductance	0.001mA/V to 2.000mA/V (1000k ohm to 0.5k ohm)
Basic Accuracy	2% voltage & current, 5% conductances
Output Signal Gains (0V to 4V)	Plate/Screen: 10mV/V Grid: 50mV/V Cathode: 40mV/mA
Heater Supplies	6.3V @ 5A 5V @ 3A
Socket Adapter Cards	Dual Triodes: 8 & 9 pin Pentodes: 8 pin A & B Power: Diodes & 300B Blank: (wire up your own socket)
AC Input Voltage	100V, 110V, 120V, 200V, 220V, 240V (Selectable)
AC Input Power	50W
Size	10" x 10" x 4" (25cm x 25cm x 10cm)
Weight	15 lbs. (7 kg)

† Hagerman Technology LLC not responsible for tube damage. See warranty.

Downloads

VacuTrace Manual (863k pdf)
Jumper Card Manual (458k pdf)

Customer Testimonials

Interesting! I have a Tek 570 but this looks more convenient and has some nice features. It is very well made and seems to work well.
I just ran through the 100 12AX7's in record time since, once your gizmo is set up, it is a very efficient replacement for the old Hickok 539C. Almost nothing to fiddle with. It's certainly a pleasure dealing with you.
I tried the VacuTrace yesterday. A real pleasure, it works great! The second tube I tested was PERFECTLY matched - a 6BX7. The third - another 6BX7 - was pretty far off. I haven't measured THD before/after, but my 6080 push-pull amp with balanced input and differential E88CC driver stage sounded clearly better after using E88CCs and 6080s with closely matched sections. I really like to work with the VacuTrace! I have been using the VacuTrace a lot this weekend - I have lots of 5687 and tons of these Russian 6C45 triodes that I needed to match for my fully differential preamp. The 6C45 were bought in matched pairs (mu and plate current). This made life a little easier - I just took all tubes with the same mu and plate current and checked them in sweep mode at the plate voltage I intend to use them. Amazing how much they differed despite having the same amplification and current values! With the VacuTrace I was able to find some pairs that in A/B mode look like one set of curves. Great! I checked some 30 JAN 5687 and found 5 that had almost 100% identical curves for the two elements.
It's possible that the VacuTrace will seem like a bargain in a few years.
I got everything up and running today, the VacuTrace is a real pleasure.
By the way, I want to compliment you on the quality of your kit. The PC board, in particular, is beautifully done. I fool with a lot of military stuff at work (I'm an instrumentation engineer at a nearby Air Force base where we do a lot of military jet engine testing) and this board looks like the kind of quality I see there, even down to the bracing of the heavy vertical caps with RTV silicone. Also, I wanted to let you know that the digital camera idea for getting the traces from o-scope to computer works quite well. I can go into the graphic programs and add scales, comments, etc. of course. Anyway, thanks for designing a neat little instrument. I've run some EL-34's thru on A-B comparison, and it works quite well.
I found the operation very easy to set up and work without a hitch.
Now your instrument is working here in Italy also. It seems really easy to test and match tubes. We are sure that it will help us quite a lot in our job.
I am very pleased with the obvious quality of the unit, documentation, packaging, etc.
I think you've done a great job, and the documentation looks first rate. A very nice piece of workmanship.
Your VacuTrace is helping us greatly in our job and I am very satisfied.
I've gotta say that your VacuTrace cuts HOURS off selecting tubes and trouble shooting tricky vari-mu foibles. I've cut the distortion by a factor of ten in my phono stage. The 'Trace also makes it easy to check batches of tubes and match newly available devices to tubes that are made out of unobtainium. Thanks for the great product!
This is the 3rd 'Trace I've bought. They are at home, work, and in my new shop! Can't get enough of them, they are so great. Thanks for the wonderful design.