Nice looking curves but low?

[Ebert Warmerdam]

L.S.,

Recently I've been measuring some new (JJ) and old (Philips) ECC83 tubes.

The curves (I(Vg, Va=Vs) with Vh constant / I(Va=Vs, Vg) with Vh constant) all have a shape nice, are repeatable and comparable to the datasheets, but are always too low. 

This accounts for the quicktest measurements as well (which are - as they should be - completely comparable to the same bias point of the curves).

Measuring the plate current on a Beck Elektroakustik Tube Tester RM1 gives values which come more in the direction of the typical characteristic of the datasheet. And testing them on a Orange Valvo Divo VT1000 tubetester all are "good" (this tester doesn't give any measurements).

So what did I do so far to correct this? Well, I've callibrated the uTracer (which made no difference) and I've switched over to an external heater supply, which gave (as expected from this uTracer Google group) a rise of the curves of about 10% but still too low.

I just don't think it's likely that all the tubes I've tested are testing low (but not impossible). Does anybody in this group have any experience in testing these triodes and can help me with some tips?

Best regards,

Ebert Warmerdam

[Hoeberlin]

Dear, Ebert,

i am quite sure this is not typical for the uTracer. I have my uTracer since many Years, and have tested many Tubes, and also made many Measurements to find out, if the Pulse Measurement is different from static Measurement. It turned out, that the uTracer is as precise as possible, within apx 1 to 2%, compared to static Measurements.

I can think of some points, that may lead to low Measurements, like long cables between Tracer Board and Tube Socket, or too many Magnetic Ferrules used. This would cause the Pulses to be round and delayed.

You may want to wire a Socket directly, max 10cm, to the Board, and measure again.

And yes, the uTracer Board tends to heat to low, but this can be eliminated by set to i.e. 6.6Volts, this needs to be tested individually.

Hope this helps,

BR Henning


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[Felix Menendez]

Hi, Ebert

¿How many tubes with "funny" readings are we talking about?

¿Have you tested tubes (how many) before with "good" readings?

¿What readings under "measured" box in Quicktest do you see? ¿Do they compare with expected readings?

Our experience with tubes is that you are to expect about 10% above or under factory specs for a "good" tube

Nevertheless, we have also tested tubes that "nailed" the factory curve...

Regards,

Félix

[Ebert Warmerdam]

Hello uTracers,

Thank you for sharing your experience and knowledge. 👍

I’m glad to read it’s not typical for the uTracer and it confirms what I was thinking that it must be me and/or my uTracer. Luckily this brings the opportunity that my problem can be solved. 😀 

So I’ve followed BR Hennings’ suggestions and removed all ferrules, shortened my cables and attached a tube with it’s tube socket directly to the uTracer. This all made no difference. 😢

I’m aware that the internal heater set to 6,63V gives 6,30V on my multimeter and results in exactly the same curves as the ones I get with an external heater supply set to 6,30V. 

With regard to Felix remarks. I’ve measured about 20 new JJECC83’s of different (long / short) plate construction and about 5 old “NOS” tubes which had tested good according to the sellers and I don’t have any reason to doubt their words. 

My (new) JJ’s have always tested low (sounded good though) and I just thought it was dew to new tubes being inferior to the old ones as one can read all over the internet. So it was just out of curiosity that I recently bought some old ones. These old ECC83’s measure a bit higher than my new JJ’s, but don’t come close to the typical characteristics.

Same story accounts for the EF86’s. Last month I got a hold of 9 old ones (all Philips Miniwatt, which were said to come out of old test equipment). All old ones measured again better (higher) than the new ones and one of the old ones measured even slightly higher than the datasheets and another one came near it’s specification. The others measured a bit lower, but still higher than my new ones.

This all doesn’t probably make it any easier, but I hope it won’t hold you back in sharing your tips.

Best regards,

Ebert Warmerdam

Op zaterdag 8 januari 2022 om 16:55:50 UTC+1 schreef Felix Menendez:

[Never Mind]

The data sheet for 12AX7/ECC83 specifies @ Va 100V, Vg -1.0V a plate current, Ia of 0.5mA.
I have noticed over the years that all brands of 12AX7/ECC83 I have tested show low Ia ( ~0.3mA) at the data sheet specified Va 100V and Vg -1.0V grid voltage.
This I this find using a accurate AVO Mark IV or a uTrancer3. Both the AVO Mark IV and the uTrancer3 produce very closely matched results.
If Vg is lowered to -0.5V~-0.8V dependent of the tube sample then Ia will rise to the specified 0.5mA value.
In all cases "good" ECC83 tubes produce values of S that are close to the data sheet values suggesting gains will be correct for the sample tube in question.

The above suggests to me the issue is not a lack of emissions or "goodness" but simply tolerance on the the Vg threshold of the ECC83 tube type.
The Vg voltage threshold tolerance is not specified on the data sheet so it is difficult to say with certainty "how much Vg tolerance is too much"
I believe if the value of S is correct for the Ia operating point in question the tube should perform correctly in a real circuit.
Indeed this seems to be the case in my experience with using ECC83 12AX7 types.
I have come to the conclusion the the ECC83/12AX7 tube type has significant Vg voltage threshold tolerance and this needs to be taken into account in testing them.

BTY The internal heater supply in the uTracer3 is in my experience so inaccurate that it can not be used to make trustworthy measurements.

Bob

[BHdeC]

Ebert,

This happens to me, constantly with some 12AX7 tubes, and not with others. I tried everything on the book as suggested. The external heater did help.

So when I face a tube with low emission, I also use my trusted Sencore MU150, and also a TV-7/D. 

90% of the time, the analog testers agree and show the tubes as perfectly working.

This is my experience and how I deal with it ATM.

I hope it helps,

Brice.

[Ebert Warmerdam]

Hello uTracers,

 

Also thanks towards Bob & Brice for their insights. I’m still hoping that I’m doing something wrong and that I can get perfect tracing out of my uTracer concerning ECC83’s.
As an illustration I’ve put the curves and the quicktests of an old Philips Miniwatt ECC83 and a new JJ ECC83 in the attachments.

 On the Orange Divo VT1000 Tube Tester both got a test status “Good” with a “Matching Value” of 9 for both sections for the Philips Miniwatt and a “Matching Value” of 7 for both sections for the JJ EC83 (it’s not clear what this ‘Matching Value” exactly is, but both sides in each tube do match according to this tester).

The Philips Miniwatt was sold to me with the specification of an AVO VCM 163 measuring: 1.25 / 1.45 mA (120% / 130%). 

 On the Beck Elektroakustik RM1 the Philips Miniwatt reads for the typical characteristic plate current 1,08 / 1,20 mA and the JJ ECC83 reads 0,84 / 0,84 mA.

So for the Philips Miniwatt I've got:
uTracer:                0,65 mA / 0,58 mA - 54% / 49%
Beck:                     1,08 mA / 1,20 mA - 90% / 100%
AVO VCM 163:     1,25 mA / 1,45 mA - 120% / 130% (obviously the vendor uses a characteristic value of around 1,1 mA looking at the percentages).
Well, this drives me a little bit crazy. I'm measuring because I want to know THE value and not lots of values for the same characteristic (AAAaaaahhhhhh!!!).

Okay, I'm fine again. I’d love to trace real curves for my triodes and hope that I don’t have to estimate what’s going on in my tubes. I’m still hoping someone can help me to achieve this.

 

Best regards,

 

Ebert Warmerdam

Op zondag 9 januari 2022 om 00:21:11 UTC+1 schreef BHdeC:

[Hoeberlin]

Hi, Ebert,

i am still thinking of what can cause this.

Tube is heated correct, with 6,3 Volts and a measured Current ( please check this ) of 0,3 A. Please be aware, that the ECC83 can be heated with 6,3 Volts or 12,6 Volts, depending on connections.

Next Idea is, that there is a Version 3 and a Version 3+ of UTracer, and as far as i remember, there is a checkmark somewhere in Calibration to be set correct.

If this doesn't solve the Problem, than you might want to do a Test with a Resistor of 250k Ohms, instead of the Tube. Connected between Anode and Cathode, run a quick test with Your ECC83 Setup, and check, if You see 1mA at 250 Volts. ( You can also use 220k instead, and recalculate the expected Current ).

In case there is something wrong with the Grid supply, You can check at -1,5 Volt, by using a AA Cell to produce a negative grid Voltage instead. Please dont use a Bench Supply for this! You also can check the Tube at zero Volts Grid, by connecting grid to Cathode, and see, if the Value is related to the Datasheets.

There is somewhere a Problem, ans we will find it.

Best Regards from German,

Henning


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[Ebert Warmerdam]

Hello uTracers,

Thank you Henning for your kind words and your perseverance. 

The tube is heated externally with a Peak Tech 6140 DC Power Supply (0-30V / 0-5A) which reads on the display: 6,2V and 0,32A.

My multimeter (Brymen BM869S brand new since last week) reads 6,30V and 0,32A.

I've got the 300+ version and the check mark in the Calibration form is correct.

I've connected the Cathode with the Anode through a 240K resistor and did afterwards - just to be sure - the same with the Screen (with Va = Vs = 240 V and 250V):

I've connected the Grid with the Cathode (every time the same JJ ECC83 is used) and a graph with the uTracer delevering the grid 0V to be able to compare the two:

I've connected the Grid with the Cathode with an AA battery in between to deliver a grid bias of -1,40V and a graph whith the uTracer delivering -1,4V to be able to compare the two;

So it seems that the grid of my uTracer is not well calibrated and / or is lower than the uTracer tells me? I'm looking forward toward your comments. Sure hope this can be fixed.

Best regards,

Ebert Warmerdam

Op zondag 9 januari 2022 om 13:11:36 UTC+1 schreef hoeb...@aol.com:

[Never Mind]

Ebert

The data you provide is great.

I can clearly see that for your Phillips and the JJ the value for Ia @Va=100 Vg=-1 is very low and well below the data sheet value of 0.5mA or the typical 0.3mA I commonly see in the many ECC83 I have tested.

By my eye there seems to be in your data only about Ia 0.1mA at Va=100V and Vg=-1V and in my experience that is outside any reasonable tolerance on ECC83 tubes.

I see in a post below you tested a 240K resistor at 240V and got 1mA suggesting the current measuring and voltage generation sections are correct.

The 240k resistor test is a very good test conforming that Va setting and Ia measuring is correct.

Rechecking at the exact point of interest of Va=100 resulting in Ia=0.5mA using a 200K resistor and setting Va to 100 volts on the uTracer will confirm that your uTracer Va can be set  accurately to 100V as well as 240V.

If you only have the 240K resistor then setting Va=120 and then reading 0.5mA will be pretty close to confirm the 100V test level is correct.

Checking the grid voltage generator on your uTracer is easy. With no tube in place connect a accurate multi meter between the grid and cathode connection on the uTracer.

Set to I (Va-Vs) with Vg-Vh constant and set the delay to about 10 seconds.

Set the grid voltage of interest to check. In this case set Vg to  -1.0V

Run the sweep. The Utracer will stay active for 10 seconds giving lots of time for the meter to settle and you to read the grid voltage.

I just checked the grid voltage accuracy on my uTracer and found with the Vg set to -1.0V I read -1.015V on my multi-meter. Pretty darn accurate.

One point of note is the uTracer grid circuit seems to have some difficulty reaching zero volts.

In the case of my uTracer setting the grid voltage to Vg=0 results in a actual grid voltage measured by the multi-meter of about -64mV.

This is a small voltage but can through off your data for the Vg=0 measurement especially with tubes like the ECC83 that have a low grid threshold voltage. As a result I avoid the zero point and set my highest Vg to -0.1V to eliminate the issue for collected data.

Bob

[Never Mind]

Ebert

Just for your reference here is a screen shot of the NOS Amperex from the early 1970s measured on my uTracer.

The measured value for Ia @ Va=100, Vg=-1V is about 0.4mA. That makes this ECC83 a pretty good match to the data sheet in my experience.

Bob

On Sunday, January 9, 2022 at 6:44:41 AM UTC-5 Ebert Warmerdam wrote:

Hello uTracers,

 

Also thanks towards Bob & Brice for their insights. I’m still hoping that I’m doing something wrong and that I can get perfect tracing out of my uTracer concerning ECC83’s.
As an illustration I’ve put the curves and the quicktests of an old Philips Miniwatt ECC83 and a new JJ ECC83 in the attachments.

 On the Orange Divo VT1000 Tube Tester both got a test status “Good” with a “Matching Value” of 9 for both sections for the Philips Miniwatt and a “Matching Value” of 7 for both sections for the JJ EC83 (it’s not clear what this ‘Matching Value” exactly is, but both sides in each tube do match according to this tester).

The Philips Miniwatt was sold to me with the specification of an AVO VCM 163 measuring: 1.25 / 1.45 mA (120% / 130%). 

 On the Beck Elektroakustik RM1 the Philips Miniwatt reads for the typical characteristic plate current 1,08 / 1,20 mA and the JJ ECC83 reads 0,84 / 0,84 mA.

So for the Philips Miniwatt I've got:
uTracer:                0,65 mA / 0,58 mA - 54% / 49%
Beck:                     1,08 mA / 1,20 mA - 90% / 100%
AVO VCM 163:     1,25 mA / 1,45 mA - 120% / 130% (obviously the vendor uses a characteristic value of around 1,1 mA looking at the percentages).
Well, this drives me a little bit crazy. I'm measuring because I want to know THE value and not lots of values for the same characteristic (AAAaaaahhhhhh!!!).

Okay, I'm fine again. I’d love to trace real curves for my triodes and hope that I don’t have to estimate what’s going on in my tubes. I’m still hoping someone can help me to achieve this.

 

Best regards,

 

Ebert Warmerdam

Op zondag 9 januari 2022 om 00:21:11 UTC+1 schreef BHdeC:

Ebert,

This happens to me, constantly with some 12AX7 tubes, and not with others. I tried everything on the book as suggested. The external heater did help.

So when I face a tube with low emission, I also use my trusted Sencore MU150, and also a TV-7/D. 

90% of the time, the analog testers agree and show the tubes as perfectly working.

This is my experience and how I deal with it ATM.

I hope it helps,

Brice.

On Saturday, January 8, 2022 at 3:43:11 PM UTC-5

The data sheet for 12AX7/ECC83 specifies @ Va 100V, Vg -1.0V a plate current, Ia of 0.5mA.

[PSchaefer]

You test the ECC83 at grid voltages between -3 and 0 V. The accuracy and the reproducibility of the grid voltage is not really good at such low values. The optimal range is -5 ... -50 V.

If you often have to work with low grid voltages, there is a "grid loupe" extension: https://www.dos4ever.com/uTracerNotebook/Notebook.html#grid2

Patrick

[Ebert Warmerdam]

Hello uTracers,

Thank you all for your time and input. I appreciate it very much. 

For Bob I've made an extra sweep of 120V with the 240K resistor between the anode and cathode and between the screen and cathode and as one can predict, this results in a straight line very close to 0,5 mA:

The grid voltages I've checked again for Bob; and with a Vg of -1, -4 and -40 Volts I get a read out on my multimeter (between cathode and grid) of -1,02, -4,04 and -40,12 Volts respectively (multimeter used is a brand new (week old) Brymen BM869S). So, nothing seems wrong with the accuracy of the grid voltage in these measurements. The problems with "0" Volts that Bo mentions could (partly) explain the somewhat higher curve I've published here earlier on request of Henning when I made a (higher) curve with the grid connected to the cathode in comparison with a (lower) curve with the grid set to 0 V in the uTracer. Because I've also done that with a comparable outcome when I compared a -1,4V grid connected to the cathode through an AA battery and -1,4V generated through the uTracer, I suspect that these differences can't be explained only by a inaccurate grid supply (which it isn't). To prevent swiping up and down I present these graphs below once again:

Thank you Bob for your reference screenshot. It shows that an ECC83, just like Henning wrote earlier in this topic, can be traced with the uTracer. I hope it will work for my uTracer as well in de nearby future (haven't lost hope yet). 

I'd like to thank Patrick for his interesting link to Ronald's website. I can remember reading it in the past and rereading it I realised why I've not build a grid loupe for my uTracer 3+. As I understand it, these grid loupes where intended for use with low plate (anode) voltages. Trying to make comparable traces to the datasheets of the ECC83's I'm using high plate voltages (up to around 300V).

Thanks again for all your input and time. It is much appreciated. I've got either a great working uTracer with (a lot of) bad tubes or I've still got a problem. 

Any suggestions are still welcome and much appreciated (please don't suggest changing my hobby from tubes to solid state technology to solve the problem..............).

Best regards,

Ebert Warmerdam

Op maandag 10 januari 2022 om 08:34:40 UTC+1 schreef PSchaefer:

[mman...@fuse.net]

I have built and used the grid loupe with success on ECC83 using my standard uT 3+. If you want to trace tubes at low plate voltages, the hardware must be modified for that purpose.

There are two issues I found with the loupe, however.

1) When measuring grid current using the screen channel there is some false current due to op amp offset. I understand that by trying several chips one that works correctly may be found.

2) There is a bug in the GUI software that prevents storing of .uts (test setup) data when the the Low Vg mode is selected. I very much wish Ronald would find the time to fix this.

Regards,

Martin Manning

---

[fmene...@gmail.com]

Hi Ebert et al,

very nice and professional comments from uTracer users. 

My "grain of salt": I would test one of your tubes in another uTracer and compare curves...

Regards

Félix

[Hoeberlin]

Hi, Ebert,

please take in account, that Tubes in general are not as precise as other electronic Components.

The given values from Datasheets are just an average ( out of 100 tubes ), and are to be met within 60% to 130% of nominal Value.

Even when new Tubes are tested to be 61% of the nominal Value, they are states as to be within Spec. 

Any Circuit Design is supposed to either automatically adjust for Variances, i.e by using a Cathode Resistor to stabilize Current, or are to be used in selected Pairs, like in some PP Output Stages.

I would not worry, if readings are low, as long as they are at least 60%.

I got a batch of tubes NOS in sealed Boxes, made for German Airforce, ( mil Spec ), andtested all. Most were in the Range of 65 to 75%, a few were close to 100, and two were above 120% of nominal Current.

Best Regards, Henning

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[Rudie]

Hi Ebert,

There was a suggestion in the past to send some valves around to other people to compare the graphs. This was not taken up because the uTracer can be tested with resistors instead of valves. Maybe in this particular case however it might be useful to send a couple of your issue tubes to somebody else and compare results. This will tell you beyond any doubt if your uTracer is consistent with other uTracers.

Regards,

Rudie 

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[Ebert Warmerdam]

Hello uTracers,

Thank you all again! Much appreciated.

For Felix' and Rudie's splendid suggestion to test some of my tubes in another uTracer I need someone whom I can send a few of my tubes.

I'd sincerely like to do this comparison before I accept - just like Brice does with his ECC83's - that it's just the way it is. Any volunteers out there? 

I am aware of the datasheets being an average as Henning wrote, although a variation - I have to be honest - of 60% - 130% is more than I expected it to be. 

Henning, you are completely right when you write that I shouldn't worry that much. After all when I put these tubes in my amplifiers they just do what they have to do and I can't hear any difference between them (this could also say something about my ears). It's just that for some unexplainable reason I simply like to know what's going on in my tubes and it is just so much more satisfying to put perfectly measuring tubes in my amplifiers, than that I put one in that is on, e.g. 65% of the nominal value. Maybe someone recognizes this, or am I the only one?

When all my JJ ECC83's measure low, it is possible that I'm just unlucky that I've got a bunch of tubes all on the left side of the curve of good old Carl Friedrich Gauss, but I still hope they are not.

And than again, when they are it's not that big a disaster, I will survive it. 

However, my Beck RM1 for instance is more optimistic about the typical characteristic plate current of these tubes. So I still got some hope. 

Intriguing world the world of tubes!

Best regards,

Ebert Warmerdam

Op dinsdag 11 januari 2022 om 13:12:37 UTC+1 schreef hoeb...@aol.com:

[BHdeC]

Hi Ebert,

I suspect you are located in Holland, isn't it? 

I can volunteer for testing your tube(s) against my Utracer, my TV7/D and my Sencore MU150 (both freshly calibrated), but I am based in NY so I am sure you may hopefully find closer volunteer(s) to you. 

A friend of mine has a MaxiTester, so that's another one.

In any case, I am here if you need me.

Brice.

[mman...@fuse.net]

Hello Ebert, what values do you have in for C10 and C11? There was a problem discovered where Vg was being dragged down during the test, and the fix was increasing the value of these two caps to lower the corner frequency of the LP filter at the output of the 0-5V Vg reference. I am using 220n and 330n, respectively, but 2x 220n might be fine.

Regards,

Martin Manning

[Felix Menendez]

Hi Ebert,

I can "volunteer" to be your second uTracer tester in case you don't find another machine nearer your home (I'm based in Spain).

My subjective feeling is that your machine is OK. ( Let's see what happens).

Besides Hennings solid comments, let's take into account the fact that different production batches at factory can show variances in final product characteristics.

Regards,

Félix

[Ebert Warmerdam]

Hallo uTracers,

Thank you Brice (yes I'm in Holland) and Felix for voluntering! Thank you Martin for your information. I've looked the article up and it's something I've completely missed!

At C10 and C11 I've got 22nF and 33nF respectively instead of 220nF and 330nF. I sincerely hope this will bring the solution. 

For those of you that are interested, I've copied the article of Martin in the attachment. 

It seems like the first thing I have to do - before sending tubes around the globe - is changing C10 and C11 to 220nF en 330nF respectively.

To be continued!

Best regards,

Ebert Warmerdam

Op woensdag 12 januari 2022 om 10:32:20 UTC+1 schreef Felix Menendez:

[Félix Menéndez]

Hi all,

I’ve missed this too!

Of course, first thing to do is implement this modification. (There is so much (and good, hi level) information from Ronald (and others, like Martin) that it’s very easy to oversee an important detail.

I’ll be watching for results (already got the capacitors…).

Regards

F

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[BHdeC]

Me too. I wasn't aware of this. Looking forward to the outcome.

Thanks for sharing.

Brice.

[BHdeC]

Guys,

I checked mine and C10 and C11 were already corrected in my kit built in 2018.

Brice.

[mman...@fuse.net]

I checked my notes, and find that I changed those two caps in October 2015 after corresponding with Ronald. The construction manual was updated with this change for uT3+ v. 3.4, which appeared sometime in mid 2016. If you built from the v. 3.3 manual (the first uT3+ manual), or the prior uT3 manual, you may have missed this update.

MPM

---

From: "BHdeC" <norman...@gmail.com>
To: "utracer" <utr...@googlegroups.com>
Sent: Sunday, January 16, 2022 9:05:40 PM
Subject: Re: Re: Nice looking curves but low?

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[Ebert Warmerdam]

Hello uTracers,

I had to wait untill my new 220nF and 330nF (both rated 100V) capacitors arrived and today they finally did. So I desoldered the 22nF and 33nf capacitors and soldered the new 220nF and 330nF capacitors respectively. Hopefull were my new quicktests of the two tubes I've been using for this topic. The old and new quicktest you'll find below:

First the JJ ECC83 before changing the capsacitors:

Second the JJ ECC83 with the new 220nF and 330nF capacitors at C10 and C11:

Third the Philips Miniwatt before changing the capacitors:

Fourth the Philips Miniwatt  with the new 220nF and 330nF capacitors at C10 and C11:

Then the curves:

Summarizing the above: the nice low curves have become higher but less nice. Is this an example of Murphy's law? Bad soldering? 

Well, it's late and I'm gonna sleep over it. Maybe I wake up with a solution for all this or maybe when I wake up someone already wrote what is happening here. 

All suggestions are welcome! Don't hesitate to blame me, because most likely it is me.

Best regards,

Ebert Warmerdam

Op maandag 17 januari 2022 om 13:13:14 UTC+1 schreef mman...@fuse.net:

[Ebert Warmerdam]

Hello uTracers,

After rereading my post I saw that I've posted the wrong I (Va=Vs) with Vh constant curve for the JJ EC83. I'd saved it wrongly (and deleted the right curve). Therefore I had to make an new one. 

Here below therefore these curves. And much to my suprise the new made curve is a nice one. 

 

Now I'm really going to sleep over it. 

Best regards,

Ebert Warmerdam

Op dinsdag 18 januari 2022 om 00:20:15 UTC+1 schreef Ebert Warmerdam:

[Martin Manning]

That's better, but the anode current is still looks a bit low. Where are you getting the heater voltage from? The uTracer's internal supply is inaccurate, so if you are using that I would find an alternate DC source that you can verify with your DMM to use as a reference. It's possible to run the internal supply at higher voltage to compensate for the lead inductance problem, but I find the over-voltage required is a function of both the particular layout as well as the heater current. 

MPM

[Never Mind]

The lumpy look of the 200nF 330nF mod is not normal in my experience. Something is not right here.

A noisy tube can cause odd curves but the curves will not be repeatable. I attached a few example curves I made

When measuring the 12AX7 type the low signal levels with Ia around 1mA and lower is builders uTracer setup noise floor.

The uTrace can do excellent measurement at 1mA but it is getting to be a pretty small a voltage (~18mV before the pGA113 amplifier) to pick out from the system noise.

This may be off topic but I wonder if anyone has experience with noisy switch mode filament supplies having any effect on low current measurements.

The uTracer internal PWM filament supply stops during the time the measurement are done so it seems Ronald took this into account with his internal filament supply design.

The uTracer internal supply has other issues that making it's us unwise so I use a clean analog filament supply just in case.

Just for interest I measured two 12AX7 and a 6N2P. The curves all look smooth.

The Amperex NOS 12AX7 is close to the data sheet of Ia=1.2mA with Va=250V Vg=-2V measuring 1.23mA, 1.22mA

But at  Va=100V Vg=-0.5V the data sheets calls up Ia=0.5mA and the sample measures only 0.24mA, 0.26mA

So this sample measures the correct Ia at Va=250V but 1/2 of the specified Ia at Va=100V

The second sample is a new Sovtec 12AX7 with Va=250V Vg=-2V measuring  0.9mA, 0.95mA about 30% low from the data sheet

At  Va=100V Vg=-0.5 the sample measures 0.16mA,  0.23mA. E lot lower than the data sheet 0.5mA

The third sample is a new NOS Sov 6n2p a close analog to the 12AX7. The 6n2p for some applications with a Cga=0.7pF vs the 12AX7 Cga=1.7pF can be useful.

 Va=250V Vg=-2V measuring  0.77mA, 0.9 mA.

At  Va=100V Vg=-0.5 the sample measures 0.16mA,  0.3mA. Pretty poor section match here.

Interesting that the 6n2p and the sovtec 12AX7 measure closer to each other than a "real" NOS 12AX7, something I have noted in the past.

I Wonder at times if some sovet made 12AX7/ECC83 tubes are in fact the guts of a 6n2p with the filaments rewired in series.

[Martin Manning]

Ebert, you did get an increase in anode current as expected, so I would call that a success. The funny looking curves are usually the result of oscillation. When I have strange results like that (and the appearance of the odd curves varies quite a bit) I add a snap-on ferrite to the grid or plate jumper lead and that usually clears it up. I haven't had issues with ECC83, usually it occurs with pentodes. Note that you can get a bad result in the quick test and not have any clue that something is wrong. Tracing the curves will reveal it. 

I am using two small B&K switch mode bench supplies, one to power the uTracer, and the other as an isolated external heater supply. I have not noticed any issues. 

[Ebert Warmerdam]

Hello uTracers,

 

It's been quite a journey since the beginning of this topic. Therefore I will summarize this journey below to keep it understandable for everyone interested, but first I’d like to thank Bob and Martin Manning for their last posts which both became very helpful today as you will discover down below. The start of all this was that my uTracer gave me nice curves but these run low (all measurements are done with the same Philips Miniwatt ECC83 tube and with an external heater supply (6,3V checked with multimeter)):

Then Martin Manning jumped in with the remark that maybe I'd missed an upgrade of the uTracer where the capacitors of C10 and C11 had changed from 22nF and 33nF towards 220nF and 330nF respectively. And indeed I had missed this. For those of you interested I've attached the substantiation for this upgrade as an attachment ("Grid Bias Tweeking"). So I ordered two new capacitors with te values of 220nF and 330nF which I received yesterday. I couldn't wait and started desoldering and soldering right away last night with the following curves as a result:

Well, now I was gone from low running curves with a nice shape to higher running curves with an irregular shape. I decided to sleep on it and luckily I did, because this gave me time to realize that maybe in my hurry and enthusiasm I had delivered sloppy (de)soldering work. One look under my uTracer today revealed that this was indeed what I had delivered. So these are the curves after cleaning my uTracer:

This is a lesson learned. I should have taken the time to clean my (de)soldering work before starting my measurements and bothering you all with the therefore wrong results. One thing I noticed is that all the Vg = 0 points in the (left) I(Vg, Va=Vs) curves are lower than one might expect out of the slope of the rest of the curve. It doesn't seem logic that oscillations are the cause of this, because it's repeatable and it''s present in more or less the same way at every anode or screen voltage (100, 150, 200, 250). Just to be sure I put a few (3) ferrites on each grid lead and this didn't make a difference:

Then I remembered that Bob had written earlier in this topic that the "0V" of the utracer wasn't exactly sero Volts. So I decided to check with my multimeter the actual grid voltages during a sweep (from -4V to 0V in 16 steps). I found the following values: -4.03 / -3.75 / -3.50 / -3.26 / -3.02 / -2.77 / -2.53 / -2.29 / -1.99 / -1.75 / -1.51 / -1.26 / -1.02 / -0.78 / -0,53 / -0.25 / -0.05. The sero value in a sweep isn't sero but -0.05V which I think is the explanation for the flatting of all the curves in the last (smaller) step. Moreover I could see exactly the same in Bob's curves that he had send in his last post in this topic (as Keith Richards said after playing "Like a Rolling Stone: "thank you Bob!").
Below you'll find like earlier in this topic - for those who are interested - a sweep with the grids connected to te cathode and a sweep with the "0V" of the uTracer (which in this case was a rounded -0.06V). The latter (-0.06V) results in a slightly lower running curve, as one might expect from all what is written above:

This brings me to thanking you all for helping me to get nice looking curves with more realistic higher values!!!
However, looking at the low curves that started this topic: they don't show this flatting as clearly as my new curves. Does anybody have an explanation for this???

Best regards,

Ebert Warmerdam

Op dinsdag 18 januari 2022 om 15:53:45 UTC+1 schreef mman...@fuse.net:

[Martin Manning]

You are correct, the sag in the last data point on the Ia vs. Vg curves is due to the inability of the uTracer's grid supply to set 0V. Using the grid loupe will eliminate that. Those curves are not really at the specified anode voltage either, as there is some sag due to the discharging of the anode and screen capacitors, and the voltage sag increases with anode current. You can see just how much that is in the Ia vs. Va curves, where the data points appear to the left of the programed voltage. Those curves are correct, though, since the actual voltage during the test is measured along with the anode current and used to make the plot. For that reason I usually don't look at !a vs. Vg, just the Ia vs. Va. I'm not sure why your earlier Ia vs. Vg curves looked better in that regard. It seems like the whole curve would have been shifted down.

[BHdeC]

I could not agree more. I've exactly witnessed what you saw. 

My conclusion, after ruling out calibration mistakes, is that you can't really measure very low current accurately with the Utracer as it is.

So when you test a 12AX7 at Va=100V Vg=-0.5mA, I think an error factor is at play here.

The TV7/D tests this tube at (too) high plate current, and maybe there is a reason for it. I haven't measured the plate current on my Sencore MU150.

But I fall back to analog testers when I want to be sure before I declare a tube unfit for duty :(.

On Monday, January 17, 2022 at 9:43:16 PM UTC-5 bobblue...@gmail.com wrote:

[Martin Manning]

Re "My conclusion, after ruling out calibration mistakes, is that you can't really measure very low current accurately with the Utracer as it is."

I have to disagree there. Measuring low current is not a problem, historically it's been setting the grid bias voltage accurately. See below, where a couple of 1M resistors are traced from 2-400V, with gains and averaging on "auto". I had just calibrated my tracer at 200V and 20 mA yesterday, and it seems to holding up pretty well down at 100V and 0.1 mA. The voltage I measured at 100V during the calibration was actually about 0.5V high, too.

[Ebert Warmerdam]

Hello uTracers,

After reading Martin’s post that the sag in the “Vg is almost 0 point” can be eliminated with the grid loupe, I would like to build one. Does anybody of us uTracers have the knowledge to design a nice small PCB lay-out for the grid loupe? 

I’m lacking this knowledge as I’m not a professional electronic engineer, but I can offer to carry the costs of the production of a small batch of grid loupe pcb’s. I think it would be nice if someone wants to do this, that I’d ask Marie-José and Ronald’s permission first before starting with this.

I haven’t got a clue how difficult the question is that I’m asking, so if it is something ridiculous, please don’t blame me and just have a good laugh 😂.

Best regards,

Ebert Warmerdam

Op woensdag 19 januari 2022 om 17:21:29 UTC+1 schreef mman...@fuse.net:

[Never Mind]

Doing a PCB layout for the grid loupe would be a piece of cake.

This is a very simple circuit and would be a mornings work to make up the PCB layout.

If you get Ronald’s permission to allow this then I am willing to do the PCB layout as I could use one myself.

If  Ronald  accepts us making a PCB of his circuit what I propose is I will do a first cut of the PCB layout and post that PCB layout and the schematic that drove the PCB layout as PDF files to this user group.

Everyone interested can then review the layout and have a say in the first cut of the layout and hopefully find any errors or omissions.

I will read through your inputs and make any corrections or changes I see as important.

So I welcome all input but do not guarantee I will take all your suggestions.

When the second cut of the PCB layout is done I will post the GERBER files to allow any PCB shop to make PCB boards and a link to the PCB shop I use to make boards. I will also post a basic BOM of the needed parts. As Ronald has already done most of the work this is not too much of my time.

For build instructions you are on your own but hopefully someone will step up and write a simple set of instructions for the less skilled that may wish to build the board. Again  Ronald has already done most of the work for whoever writes up the instructions.

As we would be using Ronald's design I fully expect the board could only be built and used for each of our personal purposes with a uTracer.

Let me know.

[Bill van Dijk]

Hi Ebert,

 

I think this is a viable idea. I have some experience and ability to design boards, I do mostly double sided, which should be sufficient for this project. I am currently looking for the schematic. I have never seriously looked into the grid loupe myself since I have never had the need for that level of detail.

 

The cost of a bunch of boards is mostly related to time. My favorite fab house is in China, and if I am not in a rush, a set of 10 small boards will cost me about $35 with an 8 to 10 week (!) shipping. If I want them faster, shipping will add up to $30 to the cost.

 

I could also do something different, place the board in the public domain, publish Gerbers, and you could order your own.

 

I looked at the schematic, and it is very simple. It could be implemented on a very small board, which could be made even smaller when using SMD parts. I am going on the assumption most people would prefer through hole, especially if they want to assemble it themselves. Alternatively, I could provide complete assembled SMD boards (depending on demand), this would also alleviate the user of the procurement of the parts. Small orders of parts tend to be expensive.

 

Design of the board would require some collaboration, such as how do you want to mount the board, is there a preferred shape (for instance, square or rectangle) and how do you want to connect to the main board. Of course you can solder wires directly to the board, or use the same type of screw connectors used on the uTracer board. There are also a number of different plug-in connectors available.

 

It is a good idea to float this by Ronald, and don’t hesitate to mention my name; he knows me.

 

Anyway, mull it over, I’m game!

 

Bill van Dijk

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[Martin Manning]

A PCB for the grid loupe has already been done by member Ihor, and he has posted the Gerber files too. Attached is my version of the loupe, built on pad-per-hole board. This layout could very easily be transferred to a PCB. In Ihor's thread we discussed the problem of a phantom grid current, which I believe is due to the lack of an offset adjustment. Fortunately, you can try a few LM348's and find a good one using a 10k resistor (connected g to k) in a test set-up. See attached for the test setup, and examples of the bad behavior that can results with some op amps. I've settled for a 20uA offset.

MPM

[Bill van Dijk]

Hi Martin,

 

Great work indeed, and wonderfully documented! Nothing for me to add.

 

Bill van Dijk

 

From: utr...@googlegroups.com [mailto:utr...@googlegroups.com] On Behalf Of Martin Manning

Sent: Saturday, January 22, 2022 10:25 AM
To: uTracer <utr...@googlegroups.com>

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[Ihor Smal]

Indeed, I just wanted to reply :) Long time ago I did a PCB for my uTracer and then even had some leftovers but I also posted the files here:

https://groups.google.com/g/utracer/c/bHcRjpb31-M/m/qTSU-AUOCQAJ

With the simple reordering (there is also screenshot in that thread) from any Chinese manufacturer you can get 5 PCBs for $4-$7 including shipping. 

Cheers, 

Ihor

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<Low Vg 10k, gk 225uA.PNG><Grid_Loupe_MPM.pdf><Low Vg 10k, gk 20uA.PNG><Low Vg 10k, gk -200uA.PNG>

[Ihor Smal]

Another link is on my website, at the bottom of that post:

http://boffin.nl/wp/utracer/

Indeed, the gridloupe works very nicely, also for for Vg around 0, and has a better “resolution” working in the range of -10V.. +5V instead of -50V..0V, where also 0V is not a “borderline” value which for sure will cause inaccuracies (but a middle of the range value).

Also true that one has to spend some time selecting LM348’s, but in my batch of 5 only one was problematic, the other 4 were good. I did ordered them from RS-Online and not from Aliexpress or ebay.

Cheers, 

Ihor

[Martin Manning]

Thanks for the kind words, Bill. 

Ihor, it took me a while, but I tried five LM348's from two different lots. Two were close to 20uA, one was at about 80uA, and the other two were way out at +/- 200 or so (as shown in the traces above). I have a few more, but I figured +20uA was good enough.

Attached is a full trace of an old 12AX7 from -4 to +1.5V Vg, with Ig measured using the loupe. Subtracting 20uA false current, the real grid current seems to stay at about 100uA until Vg goes positive.

MPM

[Ebert Warmerdam]

Hello uTracers,

Thank you so much Bob, Bill, Martin and Ihor! 👍👍👍

For Ihor: I could open the google group link, but wasn’t able to open the “boffin.nl” link.

Can I assume that Ronald is okay with this, as this is already done some time ago?

Best regards,

Ebert

Op zaterdag 22 januari 2022 om 18:29:27 UTC+1 schreef mman...@fuse.net:

[Ihor Smal]

@Martin: I think I was a bit lucky with my opamps because I remember only one was performing bad, as we discussed in that topic long time ago, and the other 4 were the same (also the results are in that thread, but I do not remember if it was at the level of 20 or 80uA). 

@Ebert: that thread in the forum contains all the information actually, but on the website you can see my other pictures. I just contacted my web hostel because indeed there are some problems with opening the page, for me it takes quite long but it opens in the end. I think the provider is under track or so. It should work tomorrow or in the future!

Ihor 

On 22 Jan 2022, at 18:49, 'Ebert Warmerdam' via uTracer <utr...@googlegroups.com> wrote:

Hello uTracers,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/b8af6aa6-4ff2-4598-95f4-d79c3e23511dn%40googlegroups.com.

[Ebert Warmerdam]

Hello uTracers,

I’ve ordered 10 grid loupe pcb’s (with Ihor’s Gerber file) for the amazing amount of almost €9 including shipping costs.

If anybody likes to have one as they arrive (estimated 12 - 20 days), just send me a message.

Best regards,

Ebert Warmerdam

Op zaterdag 22 januari 2022 om 19:49:52 UTC+1 schreef Ihor:

[jgx plato]

I have used the grid loupe pcb of Ihor (it was mounted during pandemic time!)  and it is works very well, thanks Ihor  for the execent job!

Jgxbos

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/d048778a-1c1d-4429-83af-bd97cca1733dn%40googlegroups.com.

[Ellis Brown]

Hi Ebert could I have one board Please

Regards Ellis

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[E.P.L. Warmerdam]

Hello Ellis,

You’re on the list. 👍

I’ll come back to you for the details when the pcb’s have arrived. 🛬

Best regards,

Ebert Warmerdam

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/adc56940-fae2-0a78-dd7e-937b03395428%40gmail.com.

[Martin Manning]

Hello Ebert, Can I ask who you ordered Loupe PCB's from? I've laid out a board along the lines of my prototype, and I'm planning to have some made. Perhaps some other North American uTracer users might be interested in getting one without paying for postage from the EU. I'm a bit behind you, and of course I'll have to populate one and test it before letting any go out. The new board is slightly larger than my original, but still quite compact at 46mm x 66mm.

[E.P.L. Warmerdam]

Hello Martin,

What a beautiful design! Sure you can ask me that: https://jlcpcb.com/

The postage fee isn’t that high from The Netherlands, so if anyone across the pond wants to recieve one, it’s for free. I’m very happy with all the friendly help I’m receiving from this group.

Best regards,

Ebert Warmerdam

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[jgx plato]

Hello Ebert, book one grid loupe pcb for me if it posible, and let me know instructions to pay it!

Regards from Spain!

Jgxbos

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[E.P.L. Warmerdam]

Hello Jgxbos,

 

I’ll put you on my list (no. 2 so far). No payment instructions, it’s for free.

When they arrive I will let you know through this topic.

 

Best regards,

 

Ebert

.
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[fmene...@gmail.com]

Hi, Ebert,

finally we found a bunch of valves for old battery operated radios in the junk box, so I'll be happy if you can book one pcb for us. I usually employ PayPal for these business. You'll tell me...

Regards,

Félix

[E.P.L. Warmerdam]

Hello Felix,

 

I’ll book one PCB for you (no.3). PayPal not needed, it’s for free.

I’ll notify everyone on the list through this topic as soon as the PCB’s arrive.

 

Best regards,

 

Ebert

 

Van: utr...@googlegroups.com [mailto:utr...@googlegroups.com] Namens fmene...@gmail.com
Verzonden: dinsdag 25 januari 2022 17:20
Aan: uTracer <utr...@googlegroups.com>
Onderwerp: Re: Nice looking curves but low?

 

Hi, Ebert,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/fe636ce4-20ac-4a88-866b-759af0a8f148n%40googlegroups.com.

[Bill van Dijk]

Hello Ebert,

 

Would you be so kind as to add me for one board on the list? I am located in Canada, so I would be more than happy to at least reimburse you for the mailing cost!

 

Cheers, Bill

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[E.P.L. Warmerdam]

Hello Bill,

Your (quite Dutch 😀) name is on the list (no.4).

Mailing costs won’t be a problem, also for Canada it’s free.

As soon as the pcb’s arrive I will post it in this topic.

Best regards,

Ebert

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[televe]

Ebert,

Please put my name on your list, if there are any left.

Many thanks,

Terry

Virginia, USA.

[E.P.L. Warmerdam]

Hello Terry,

 

You’re on the list (no.5). J

 

Best regards,

 

Ebert Warmerdam

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[Davo]

Can someone please tell me what’s the use of the gridloupe?

I’m a bit confused.. 

i saw it on Ronalds site, that it was a addon for low voltage tubes. Used in car radios etc.

But i see all these messages come by about false readings with ECC83 & that the gridloupe could solve those issues ?

And those false readings, was it only related to the ECC83 or all 12AX7 tubes?

Kind regards,

Dave

Op 26 jan. 2022 om 19:30 heeft 'E.P.L. Warmerdam' via uTracer <utr...@googlegroups.com> het volgende geschreven:



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[Bill van Dijk]

Dave,

 

I have no idea how I could make the purpose of the grid loupe any clearer than Ronald made it on his weblog. He wrote:

 

From the experiments in the previous section it became clear that the grid supply of the uTracer is not really adequate when it comes to studying the behavior of tubes at very low plate voltages. The grid supply of the uTracer was designed to generate bias voltages over the range of -50 to 0V and it cannot supply or sink any significant currents. However, at (very) low plate voltages most tubes only start to show a noticeable anode current for grid biases in the range of -2 to 0V. Besides this, at low plate voltages, the grid starts to draw significant currents for grid biases below -0.5V (I think the mathematical correct way of saying this would be: for grid biases higher than -0.5V). The reason is that for low plate voltages less electrons are pulled to the plate, so that they can contribute to the grid current.

 

This thread originally started with another problem which was solved, and migrated into the grid loupe discussion. To get the full context you would have to read the thread from the beginning.

 

Cheers, Bill

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[Martin Manning]

Except I would add that the grid loupe is not just for low plate voltages. It can set exactly 0V (which the standard grid supply can't do), set positive bias up to +5V, and sink some current. If you don't care about getting to exactly zero, or running positive grid bias, then the standard supply is fine- as long as your uTracer has the C10=220n and C11=330n update identified in the thread. That was implemented in kits shipped in 2016.

I went with PCBWay for my Loupe PCB's, and a batch of ten is in production now. I have all of the parts on hand to populate one and test it as soon as they arrive, which will probably be within a week.

MPM

[Davo]

Thanks for the clarification Martin & Bill!

It looks like I regularly missed quite some post lol

This thread has more post as I thought…

It’s only hard to read due my email client.

But anyway, it seems to looks like this gridloupe is quite essential to have good measurements with 12ax7 variants.

I have the latest version of the uTracer, i guess… I Bought it in Oct ‘21

But I still haven’t completed my tester lol

Still busy with the design and addons etc.

I have some ecc83’s and other variants that i want to test haha but i’m keeping adding & removing stuff to the project.

I really like the design project, but sometimes i can be a real pain also..

Verstuurd vanaf mijn iPhone

Op 26 jan. 2022 om 23:32 heeft Martin Manning <mman...@fuse.net> het volgende geschreven:

Except I would add that the grid loupe is not just for low plate voltages. It can set exactly 0V (which the standard grid supply can't do), set positive bias up to +5V, and sink some current. If you don't care about getting to exactly zero, or running positive grid bias, then the standard supply is fine- as long as your uTracer has the C10=220n and C11=330n update identified in the thread. That was implemented in kits shipped in 2016.

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/768b990c-87f5-4212-99bd-83474c54a813n%40googlegroups.com.

[Boban]

Hi

Can someone provide more info for C10=220n and C11=330n like part number from Digikey or Mouser?

Or at least what voltage rating they should be? Thanks in advance.

My kit is rather old (around 2013) and likely not with those values. Have not opened the box yet.

regards

Boban

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[Hoeberlin]

Hi, Boban,

i actually have build a μTracer Board this week. The two Caps are 63Volts. BR Henning


Von der neuen AOL-App für iOS gesendet

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[Martin Manning]

63V TDK box caps: B32529C224J and B32529C334J

[Martin Manning]

Boban, you may be missing another fix: 10n caps across R21 and R34, which improves the Quick Test accuracy.

[Boban]

Than you all.

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/e4105120-6768-4991-8d67-ca185774227fn%40googlegroups.com.

[Félix Menéndez]

Will somebody (maybe Martin?) summarize the ‘modifications’ developed so far for the uTracer?

Maybe that list could be added somewhere into uTracer’s web as a handy check list for our uTracers’ “mod. Level”…

Regards

Félix

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[Davo]

Hi felix, one thing came into my mind…

There are a few upgrades on the main chip on the uTacer also.

Mine is V26G

I don’t know if you can run into problems when doing upgrade’s on the board?

Maybe some experienced user here give some clarification about that…

Verstuurd vanaf mijn iPhone

Op 29 jan. 2022 om 11:26 heeft Félix Menéndez <fmene...@telefonica.net> het volgende geschreven:



To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/001801d814fa%2496f09b80%24c4d1d280%24%40net.

[Ihor Smal]

All the mods are more or less described here, some interesting ones are:

https://www.dos4ever.com/uTracerNotebook/Notebook.html

2. Boost the speed of your uTracer (a bit).

7. Tweaking the uTracer for low voltages and low currents.

8. Build a grid loupe (for less than 10 euro/dollar)!

11. A powerful buck converter and digital display for the heater by Albert Valiente!

15. Higher Currents II: A Step-by-Step Manual

and I also have to mention one of mine :)) 

20. uTracer goes WiFireless using ESP32 and webinterface

Cheers, 

Ihor

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/001801d814fa%2496f09b80%24c4d1d280%24%40net.

[Martin Manning]

My firmware is uTracer3 v26c, original to my build in October 2013. I've since converted it to a 3+ (400V Va, Vs), and made all of the modifications discussed in this thread. I don't believe the two caps I mentioned above (10n piggy-backed on R21 and R34) are mentioned in the notebook pages, but if you look at the 3+ construction manual 3.3 you will see them. They are called  C35 and C37, and in the manual they are shown soldered to pads on the back of the board. In that manual the processor shown in the photos is marked v26c.

[Félix Menéndez]

Hi, Ihor,

Thanks for the answer. Yes, I already know the Labnotes Tab. What I’m referring to is that I’m beginning to find it confusing to ascertain that my machine is up to the latest hardware/firmware level. In that Labnotes tab you can see many things that don’t apply to your machine. I’m not sure if I’m overlooking something. I need to know all Field Retrofits that affects the design performance of my uTracer. A list with those FROs (Field Retrofit Orders) that affect every uTracer version would be nice to have.

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/DD8C7094-6F9C-4BD7-A02C-730FE5B9E965%40gmail.com.

[Ihor Smal]

Hi Félix,

Then one of the solutions is just to take the latest schematics from the website and compare to that. All the things in the labor are hacks which are not in the latest version. 

Also looking at the testimonials https://www.dos4ever.com/uTracer3/uTracer3_pag9.html I see that indeed a few latest sets have v26g firmware. I have not check any updates/information about that but to be up-to-date the only way is to but the new PiC with that firmware from Ronald for €20.

Cheers,

Ihor 

On 29 Jan 2022, at 17:30, Félix Menéndez <fmene...@telefonica.net> wrote:



To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/001201d8152d%247d0f0e80%24772d2b80%24%40net.

[Félix Menéndez]

Hi Ihor,

Well… if you take a look at Downloads Tab (uTracer 3) you see pic version “C”. But it happens that a version “G” exists. So we arrive to the point: a centralized “box” where to look at for versions (hard/soft). I think that searching various places is an error prone system. Moreover: how can you tell that a schem. is the latest…?

Maybe I don’t use the uTracer web properly, as I enter from time to time. Your “tips” are welcome.

Regs.

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/B3D8B866-910E-4928-9978-6DD8BA7CB12C%40gmail.com.

[Ihor Smal]

Hi Félix, 

I agree that it is good to have all the things updated, but I believe it is already like that on the website. So the schematics that you see in the Downloads (build instruction v.3.8) should be the latest one. Makes sense that Ronald keeps that pdf updated because uTracer 3+ is still on sale, and if there are changes in the shipped kits, that pdf would be updated. 

As I mentioned, in the Testimonials the most recent builds of uTracer 3+ show version v26G in the pictures. Of course that’s just a version of the firmware so the schematics does not change, the PIC is the same. Most likely Ronald fixed or improved some algorithms for acquiring the data and so on, and most likely, that firmware update has nothing to do with any schematics changes. I could not find anything about the update in firmware from v26c to v26G to confirm that, but my point was that in any case you cannot upgrade the firmware yourself (even if you have a programmer) without buying the the PIC from the website (just because the code is not in a public domain). 

Ihor

[Martin Manning]

I have comprehensive notes on the mods I've made, which are: 

Change C10 and C11 to 220n and 330n

Add 10n over R34 and R21

3+ conversion per the website

As far as I know, those are the upgrades to improve the basic performance. I've also doubled (paralleled) the boost converter inductors, removed the RS232 driver to use an FTDI USB-TTL adapter cable, and added the grid loupe. 

I'm curious about the updated firmware and what that might bring. In Ronald's last group e-mail he mentions that he is redoing the uT3 board, I assume to gather up the fixes and the 3+ part changes.

[D.A.R Achterberg]

I didn’t knew you made the wireless mod Ihor, nice build! It’s not suitable for me, because i run the uTracer software on a mini pc that is stored in the housing but i can understand someone would love the addon to get rid of the data cable.

Verstuurd vanaf mijn iPhone

Op 29 jan. 2022 om 21:48 heeft D.A.R Achterberg <d.a.r.ac...@gmail.com> het volgende geschreven:

Felix don’t have enough knowledge to look into that, but i think sending an email to Ronald Dekker is the way to go to get the best answer according to the PIC and other hardware changes to the board…

I did read on Ronald’s site that there were also revisions on the PCB also, but i really don’t know if  affect the working parts of the system?

Ronald is the way to go IMHO

To bad Ronald’s site is such a mess lol

He’s a genuis as it comes to the uTracer, but his site is like the opposite though.

Ronald is lucky that his wife i such organised, orherwise his household and distribution of the uTracer i guess haha

Another thing, I don’t know if you guys tried the uTmax software?

It has sum really cooladdons like resizable windows, which is a real plus, because with the original software it can be a real pain to select a point on the graphic window, especially with the laptop mouse control. But visually it’s more relaxing also to have full screen, and you can even change the layout, not that important, but a nice addon.

You can have multiple tabs also which make it more organised.

A way more advanced system to recall tube settings which is a big plus also for me. He also has a linux version.

To bad he dusn’t have a version that is in the ARM64 architecture. So you could run it on a Raspberry Pi, it’s rock solid fast and in a small device.

Well this thread i way off-topic haha

That it brings me this whole email based system, which is such a pain to read through!

An actual forum would be the way to go to keep things organized, updates, sticky’s.

To bad Ronald dusn’t have a forum!

His site is all plain HTML this is so 90’s lol

There are many free PHP forum plugins nowadays, so I don’t think that’s the reason he hasn’t got a forum.

I guess he thinks it would be a-lot off work maintaining the forum, and answering questions. The uTracer fam is quite big so it would be easy to find some moderators…

And I personally think that it would be good source for Ronald to improve his uTracer… 

Verstuurd vanaf mijn iPhone

Op 29 jan. 2022 om 19:26 heeft Félix Menéndez <fmene...@telefonica.net> het volgende geschreven:



Hi Ihor,

Well… if you take a look at Downloads Tab (uTracer 3) you see pic version “C”. But it happens that a version “G” exists. So we arrive to the point: a centralized “box” where to look at for versions (hard/soft). I think that searching various places is an error prone system. Moreover: how can you tell that a schem. is the latest…?

Maybe I don’t use the uTracer web properly, as I enter from time to time. Your “tips” are welcome.

Regs.

Félix

 

De: utr...@googlegroups.com [mailto:utr...@googlegroups.com] En nombre de Ihor Smal

Enviado el: sábado, 29 de enero de 2022 18:05
Para: utr...@googlegroups.com
Asunto: Re: Nice looking curves but low?

 

Hi Félix,

 

Then one of the solutions is just to take the latest schematics from the website and compare to that. All the things in the labor are hacks which are not in the latest version. 

 

Also looking at the testimonials https://www.dos4ever.com/uTracer3/uTracer3_pag9.html I see that indeed a few latest sets have v26g firmware. I have not check any updates/information about that but to be up-to-date the only way is to but the new PiC with that firmware from Ronald for €20.

 

Cheers,

 

Ihor 

On 29 Jan 2022, at 17:30, Félix Menéndez <fmene...@telefonica.net> wrote:



Hi, Ihor,

Thanks for the answer. Yes, I already know the Labnotes Tab. What I’m referring to is that I’m beginning to find it confusing to ascertain that my machine is up to the latest hardware/firmware level. In that Labnotes tab you can see many things that don’t apply to your machine. I’m not sure if I’m overlooking something. I need to know all Field Retrofits that affects the design performance of my uTracer. A list with those FROs (Field Retrofit Orders) that affect every uTracer version would be nice to have.

Regards

Félix

 

 

De: utr...@googlegroups.com [mailto:utr...@googlegroups.com] En nombre de Ihor Smal
Enviado el: sábado, 29 de enero de 2022 14:26
Para: utr...@googlegroups.com
Asunto: Re: Nice looking curves but low?

 

All the mods are more or less described here, some interesting ones are:

https://www.dos4ever.com/uTracerNotebook/Notebook.html

 

2. Boost the speed of your uTracer (a bit).

7. Tweaking the uTracer for low voltages and low currents.

8. Build a grid loupe (for less than 10 euro/dollar)!

11. A powerful buck converter and digital display for the heater by Albert Valiente!

15. Higher Currents II: A Step-by-Step Manual

 

and I also have to mention one of mine :)) 

20. uTracer goes WiFireless using ESP32 and webinterface

 

Cheers, 

 

Ihor

 

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/002301d8153d%249777aa60%24c666ff20%24%40net.

[D.A.R Achterberg]

Felix don’t have enough knowledge to look into that, but i think sending an email to Ronald Dekker is the way to go to get the best answer according to the PIC and other hardware changes to the board…

I did read on Ronald’s site that there were also revisions on the PCB also, but i really don’t know if  affect the working parts of the system?

Ronald is the way to go IMHO

To bad Ronald’s site is such a mess lol

He’s a genuis as it comes to the uTracer, but his site is like the opposite though.

Ronald is lucky that his wife i such organised, orherwise his household and distribution of the uTracer i guess haha

Another thing, I don’t know if you guys tried the uTmax software?

It has sum really cooladdons like resizable windows, which is a real plus, because with the original software it can be a real pain to select a point on the graphic window, especially with the laptop mouse control. But visually it’s more relaxing also to have full screen, and you can even change the layout, not that important, but a nice addon.

You can have multiple tabs also which make it more organised.

A way more advanced system to recall tube settings which is a big plus also for me. He also has a linux version.

To bad he dusn’t have a version that is in the ARM64 architecture. So you could run it on a Raspberry Pi, it’s rock solid fast and in a small device.

Well this thread i way off-topic haha

That it brings me this whole email based system, which is such a pain to read through!

An actual forum would be the way to go to keep things organized, updates, sticky’s.

To bad Ronald dusn’t have a forum!

His site is all plain HTML this is so 90’s lol

There are many free PHP forum plugins nowadays, so I don’t think that’s the reason he hasn’t got a forum.

I guess he thinks it would be a-lot off work maintaining the forum, and answering questions. The uTracer fam is quite big so it would be easy to find some moderators…

And I personally think that it would be good source for Ronald to improve his uTracer… 

Verstuurd vanaf mijn iPhone

Op 29 jan. 2022 om 19:26 heeft Félix Menéndez <fmene...@telefonica.net> het volgende geschreven:



Hi Ihor,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/002301d8153d%249777aa60%24c666ff20%24%40net.

[Ihor Smal]

I didn’t knew you made the wireless mod Ihor, nice build! It’s not suitable for me, because i run the uTracer software on a mini pc that is stored in the housing but i can understand someone would love the addon to get rid of the data cable.

Verstuurd vanaf mijn iPhone

Actually the ESP32 interface can run on anythingthat has a web browser. so it can be raspberry pi, iphone, ipad, macbook, any arm64 systems and so on :) Also to have a pc somewhere stored in not a problem, as long as it connected to your WiFi LAN. With ESP32 addon you have access to your  uTracer from any device in your LAN. The webinterface also have all the features from uTmax and original iTracer software combined, with lots of improvements, tube modeling, storing the plots, matching 2 or 4 tunes in one plot, database with tubes and pinouts, tool to design load lines for your amplifiers, export to pdf and so on. You can even have a plots full screen, which would be perfect for your laptop: ))  

some videocasts but most of the thins can be found in the post on ESP32 here in the forum:

http://files.smal.ws/JY7280

http://files.smal.ws/lUMewP

http://files.smal.ws/Ezbq3p

By the way, about the forum, indeed it would be veery easy to switch to another platform, but we would beed someone who agrees to support it for years, and that will be a problem I think. I am not sure if you aware but as I understood Ronald is not running this googlegroups and only reads the posts. It was established by the users of uTracer and the number of users here (268) is way less compared to the number of sold utracers (thousands) :)   

Ihor

[Félix Menéndez]

D.A.R. Achterberg:

Yes, addressing this issue to Ronald would be the right way to go, but I don’t want to bother a busy engineer that runs this design as half a business half a hobby with a theme that is mainly internal organization and requires paper labor J.

Thank you for your comments.

Ihor and Martin:

Many thanks for your words. I will try to visit Ronald’s web more often and try to keep myself informed thru your posts.

Regds.

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/1BCCAF43-172D-4619-9CB9-ED8F9BE18A80%40gmail.com.

[PSchaefer]

Ihor schrieb am Samstag, 29. Januar 2022 um 20:28:03 UTC+1:

 

As I mentioned, in the Testimonials the most recent builds of uTracer 3+ show version v26G in the pictures.

This should be a "c". Somewhere on his website Ronald mentioned that this "c" means "code protected", i.e. the PIC's security fuse bits are set.

V2.6 is the latest firmware for µTracer 3+

[Ihor]

The 26c version was even in my 2018 uTracer, now all the new builds definitely have "G"

[Martin Manning]

After a short delay for Chinese New Year celebrations, another grid loupe PCB has passed acceptance testing. Grid voltages are within a few mV of my old loupe across the -10 to +5V range using the same calibration file.

MPM

[Nebojsa Tomic]

Hello Ebert, 

Can you please book one grid loupe pcb for me if there any left, 

and let me know instructions to pay for it.

Regards from Belgrade!

Nebojsa

On Saturday, January 22, 2022 at 10:26:31 PM UTC+1 Ebert Warmerdam wrote:

Hello uTracers,

[Ebert Warmerdam]

Hello uTracers,

Nice clean soldering Martin!

Nebojsa, I've put one the list (no.6) for beautiful Belgrade as well.

My PCB's haven't arrived yet, but as soon as they arrive I'll come back to this topic.

Best regareds,

Ebert Warmerdam

Op woensdag 9 februari 2022 om 18:52:02 UTC+1 schreef nesk...@gmail.com:

[Davo]

Hi Ebert warmerdan, 

could you put me on the list also?

I really like the layout!

Do you have  a parts list also…

Kind Regards,

Dave Achterberg 

Op 10 feb. 2022 om 17:42 heeft 'Ebert Warmerdam' via uTracer <utr...@googlegroups.com> het volgende geschreven:

Hello uTracers,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/e2b63b15-26ac-4fd6-9024-bcfacd7c293en%40googlegroups.com.

[D.A.R Achterberg]

I checked the schematic for the gridloupe 

And like like this are the gridloupe part:

R1= 1k

R2 = 42k

R3 = 42K

R4 = 121k

R5 = 121 K

R6 = 10R

R7 = 12.1K

R8 = 12.1K

R9 = 121K

R10 = 121k

R11 = 100

r12 = 180r

r13 = 180r 

r14 = 180r

C1 = 10uF 25V

C2 = 150nF

c3 = 10uF 25v 

c4 = 150nF

c5 = 10uF 25v

c6 = 150nF 

T1 = KSP44

IC1 = LM348

IC2 = LM7812

IC3 = CRE1S1212SC

But is did’t see anything about the 5v option

Op 10 feb. 2022 om 17:42 heeft 'Ebert Warmerdam' via uTracer <utr...@googlegroups.com> het volgende geschreven:

Hello uTracers,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/e2b63b15-26ac-4fd6-9024-bcfacd7c293en%40googlegroups.com.

[Ebert Warmerdam]

Hello uTracers,

I've received the PCB boards. On the list are:

1. Ellis

2. Jgxbox

3. Félix

4. Bill

5. Terry

6. Nebojsa

7. Dave Achterberg

You can send me your address through my (Dutch) website:

Verwijsbrieven (warmerdamveterinaireradiologie.nl)

This page is in Dutch but I will help you through it:

E-mail adres = (your) email address

Onderwerp = subject (e.g. "grid loop PCB board")

Toelichting = explanation (here you can write down your address and anything else you want to say)

Ik ben geen robot = I'm not a robot (click to confirm if your not a robot, don't click it if you are a robot)

Best regards,

Ebert Warmerdam

Op vrijdag 11 februari 2022 om 18:54:17 UTC+1 schreef d.a.r.ac...@gmail.com:

[Bill van Dijk]

Done.

 

With my sincere thanks!

 

Bill v

 

From: 'Ebert Warmerdam' via uTracer [mailto:utr...@googlegroups.com]
Sent: Friday, February 18, 2022 3:29 AM
To: uTracer <utr...@googlegroups.com>
Subject: Re: Nice looking curves but low?

 

Hello uTracers,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/a4fd24a3-a725-47e9-bd09-b4df38bf34a7n%40googlegroups.com.

[jgx plato]

Done! Thank you very much Ebert!!!

Regards 

Jgxbos

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/a4fd24a3-a725-47e9-bd09-b4df38bf34a7n%40googlegroups.com.

[Davo]

Awsome Egbert!

Just arrived @home!

Driving home wasn’t a pleasure with that storm (Eunice) over here..

Don’t click if your a robot lol

Grtz,

Dave

Op 18 feb. 2022 om 16:38 heeft jgx plato <jgx...@gmail.com> het volgende geschreven:



To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/CALFq-68VU%2BYK2Jxtus1of4cd_tizrX2p1gxopdej1JGc2-qkXg%40mail.gmail.com.

[D.A.R Achterberg]

Mail Send

Verstuurd vanaf mijn iPhone

Op 18 feb. 2022 om 17:40 heeft Davo <djda...@gmail.com> het volgende geschreven:

Awsome Egbert!

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/ED917DC3-C11D-48B3-8327-8F32FAC24089%40gmail.com.

[Doug LeVan]

Greetings,

I'd be interested in a grid loupe pcb if it's still available.

Regards,

Doug

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/d048778a-1c1d-4429-83af-bd97cca1733dn%40googlegroups.com.

[E.P.L. Warmerdam]

Hello Doug,

No problem! Just follow the link I posted a few posts up.

Best regards,

Ebert Warmerdam

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/CADO2_QQEBNWNkkQGWJBZTGiM-Chbvf6t6W37-hCadJzY17ZB9A%40mail.gmail.com.

[Doug LeVan]

I just filled out the form on your website.

Interesting that you work in Veterinary radiology.

I worked in the X-Ray business for 30 years installing and servicing X-Ray equipment in hospitals and office settings.

We also did Veterinary and Industrial/NDT systems.

The last 10 years or so of that time was mostly PACS work for me.

I've spent the last 12 years servicing and installing Lithotripsy (Karl Storz) equipment.

Retirement is near :)

Thanks for sharing your PCBs.

Please let me know if I can at least reimburse you for the postage.

Best regards,

Doug

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/7A1A53FE-E89B-43B8-85FE-300BDDEA1CD8%40casema.nl.

[Ebert Warmerdam]

Hello uTracers,

I've delivered all the PCB's at the postal office today. 
I hope they all will arrive soon and in good condition.

Only Terry from Virginia (USA)) hasn't send me his address yet.

So Terry, if you read this, don't forget to send me your address.

Thanks again Ihor for designing the Gerber file and letting me use it.

Best regards,

Ebert Warmerdam

Op zaterdag 19 februari 2022 om 01:37:33 UTC+1 schreef doug....@gmail.com:

[Davo]

Wow that’s fast Egbert!

I really appreciate it!🙏🏻

Grtz,

Dave

Op 19 feb. 2022 om 13:58 heeft 'Ebert Warmerdam' via uTracer <utr...@googlegroups.com> het volgende geschreven:

Hello uTracers,

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/384b2370-cd5b-4e7f-b800-0e02d815b7e1n%40googlegroups.com.

[Esteban Bikic]

Hi, I received the uTracer 6 yesterday, well protected and with a manual. Incredible people you are!!!

Esteban Bikic

Menorca, Spain

El 19/2/22 a las 13:58, 'Ebert Warmerdam' via uTracer escribió:

To view this discussion on the web visit https://groups.google.com/d/msgid/utracer/384b2370-cd5b-4e7f-b800-0e02d815b7e1n%40googlegroups.com.