uTracer (Micro Curve Tracer)

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martin manning
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uTracer (Micro Curve Tracer)

Post by martin manning »

So I have one of these things on order: http://www.dos4ever.com/uTracer3/uTracer3.html I's going to be fun! Lots of interesting reading on the site about the project and the history of such things. Delivery is a couple of weeks out, but I'll post results as they happen.
Last edited by martin manning on Mon Mar 02, 2015 3:25 pm, edited 3 times in total.
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Reeltarded
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Re: uTracer (Micro Curve Tracer)

Post by Reeltarded »

That looks complicated and awesome!

-continues reading- -drools a little-
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martin manning
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Re: uTracer (Micro Curve Tracer)

Post by martin manning »

It should be very useful. Looking for some way to test and grade tubes I concluded that vintage testers are not worth the trouble, and investing in an Amplitrex for hobby use would be silly. I first thought (a lot) about doing a PCB for and building the RAT (rec.audio.tubes) tester designed by S Bench (with that at least you know exactly what the test conditions are), but the u-Tracer goes much further for about the same cash outlay and effort. An Amplitrex can test at somewhat higher voltages, but it is also 10x the cost of the basic u-Tracer parts kit.
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cbass
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Re: uTracer (Micro Curve Tracer)

Post by cbass »

Cool.I've got a bunch of tubes you can test :wink:

So it goes up to 300 volts?
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Reeltarded
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Re: uTracer (Micro Curve Tracer)

Post by Reeltarded »

Buddy in Florida use to have an old tube tester he called "Old Sparky" and I refused to stand there while he used it. Similar feeling when someone takes a freshly built hipo motor into uncharted revs.

I am scared of explodey things and anything that make lightning.
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Re: uTracer (Micro Curve Tracer)

Post by JazzGuitarGimp »

Thanks for posting, Martin. I am looking very forward to hearing what you think about the uTracer.
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Re: uTracer (Micro Curve Tracer)

Post by sergio »

Hi , I have one, and it's really a nice little machine.
with RS232 works great , with usb port have some problem but i think it's a chip problem of the serial converter!
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martin manning
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Re: uTracer (Micro Curve Tracer)

Post by martin manning »

uTracer is up and running for trials, but not packaged for everyday use yet. Shown here is some data from the first test runs, conducted using an EH 6V6GT. The supplied software produces plots for viewing and measurements, but I chose to dump the raw data into Excel for analysis. The test run is sweeps of Va at constant Vg2 and Vg1, which were selected to match the data sheet specs at 250V Vg2 and -12.5V Vg1. I ran the -12.5 Vg1 curve to check Ia against the spec, plus another one at -11.5V Vg1 to calculate gm, and also a Vg1 = 0. This tube looks pretty good as it is within 2% of the data sheet Gm and showing 110% of the current. The data sheet shows 112mA a Vg1 = 0, and the test produced 122mA, 109% of spec. Screen current is measured during the sweeps too, I just didn't pull it out. There is a lot more to learn about this thing!
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Structo
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Re: uTracer (Micro Curve Tracer)

Post by Structo »

Pretty cool Martin.

As long as you know what all those numbers mean. :lol:

What does the yellow highlighted rows signify?


What did you use for a power supply?
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martin manning
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Re: uTracer (Micro Curve Tracer)

Post by martin manning »

Thanks, Tom. I'm running from a small DC bench supply at 20V, but it is designed to use a laptop PC brick. The board has four DC to DC converters that produce the required plate, screen, grid, and filament voltages from ~20V DC. The data sheet (GE, from '55) quotes current and transconductance at 250V plate and screen, -12.5V g1. The highlighted numbers are the raw data at those conditions, and I used Excel to interpolate to 250V Va and calculate the Gm. I believe if I had set up the run correctly I would have gotten data at 250V.
Last edited by martin manning on Sun Apr 05, 2015 12:28 pm, edited 1 time in total.
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Re: uTracer (Micro Curve Tracer)

Post by Reeltarded »

I need to pack a box for you I know don't shoot me.
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Re: uTracer (Micro Curve Tracer)

Post by Phil_S »

Shazam!
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Re: uTracer (Micro Curve Tracer)

Post by Randall »

I just bought a five pack of 12AY7s that came with a the prints from each tube from the uTracer v.3. I have no idea what it all means, except that he stated they were all within 95% of original spec.
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martin manning
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Re: uTracer (Micro Curve Tracer)

Post by martin manning »

Randall wrote:I just bought a five pack of 12AY7s that came with a the prints from each tube from the uTracer v.3. I have no idea what it all means, except that he stated they were all within 95% of original spec.
What that means is you know exactly what you bought, and that the seller is legit.
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Re: uTracer (Micro Curve Tracer)

Post by VacuumVoodoo »

martin manning wrote:uTracer is up and running for trials, but not packaged for everyday use yet. Shown here is some data from the first test runs, conducted using an EH 6V6GT. The supplied software produces plots for viewing and measurements, but I chose to dump the raw data into Excel for analysis.
Martin, is the raw data dump a built in function in the SW or did you need to tweak it to pull it out? I am an analog continuous world guy, gave up SW after FORTRAN and punch cards.
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