Curve tracer questions


bill koski
 

I didn't want to sidetrack the current 570 thread with a couple related questions.
First has anyone here built one of Ron Dekker's U-Tracer and what are your opinions?

Second I've not had the privilege of using a tracer yet,
I was wondering if you could test a tube with various values of cathode resistors inserted to see
directly the effects of the NFB of the cathode resistor has on a given tube's curves?


Glydeck
 

You might find better answers with the tube tester group.

https://groups.io/g/TubeTesters

On Aug 27, 2021, at 6:43 AM, bill koski <tubesrus4@gmail.com> wrote:

I didn't want to sidetrack the current 570 thread with a couple related questions.
First has anyone here built one of Ron Dekker's U-Tracer and what are your opinions?

Second I've not had the privilege of using a tracer yet,
I was wondering if you could test a tube with various values of cathode resistors inserted to see
directly the effects of the NFB of the cathode resistor has on a given tube's curves?






Ke-Fong Lin
 

First has anyone here built one of Ron Dekker's U-Tracer and what are your
opinions?
I've built the uTracer 3+. If you like building things, especially electronics, then it's a blast.
It's very easy, only a few SMT (inductors, less than 10), other SMTs come pre-soldered.
Kit is complete, parts all provided, high quality (probably sourced from Mouser or Farnell).
PCB is probably from Belgium. There's even a full construction manual.
You will need an 18-20VDC supply, easy to find.

I do have some interest regarding tubes, mainly because of guitar/bass amps.
However, it's not my main topic of interest, and I'm not an expert. So take my opinion for what is worth.

Regarding the capabilities, I think it should be about the same as 570 or 575. But you may not be able to test power tubes.
It's fully software driven, you will need a PC/laptop running Windows. It's RS232 so you'll also need an USB to RS232 (cheap and easy to find).
Some people may prefer one knob/switch = one function instead of clicking around. The 570 really good in that regard.
With a PC, it's easier to take screenshot, or maybe even dump .csv files of curves.
I've not played that much around, trying a few EF86 and 12AX7 around but works well.

Now, a few bad things:
1) The heater supply is not working. It's not a real buck converter (Ronald doesn't claim it), see the schematic for yourself.
It's no big deal as you can use a bench supply instead.
2) There is no case and you have to make all connections yourself. In fact, I'm lazy, so I've used dangling wires.
3) uTracer 3+ may lack power and voltage for some tubes (not an issue for me), uTracer 6 correct that.

Second I've not had the privilege of using a tracer yet,
I was wondering if you could test a tube with various values of cathode
resistors inserted to see
directly the effects of the NFB of the cathode resistor has on a given tube's
curves?
As you do the connections yourself, you can insert any resistor in serie with the cathode.
But may be the easiest and best thing to do, is to contact Ronald Dekker directly. I've talked a few times by email with him, he's very helpful and friendly.


David Holland
 

"Sames"....

This is mine:

https://www.antiqueradios.com/forums/viewtopic.php?p=3291915&sid=7875ae10ce3b21aaf98bbe2c7d3ffa4b#p3291915
(I claim it's on-list as the case is a Tektronix one.)

Ke-Fong Lin, summarized it pretty well. Builtin Heater supply is
somewhat poor (I built an external 50V one into the case, and a little
buck regulator.) 3D printed a thingy to hold tube sockets. All in
all, it works well, was fun to assemble too.

I haven't heard if the UT6 has gotten out of "beta" and is officially
on sale yet though.

David

On Fri, Aug 27, 2021 at 4:11 PM Ke-Fong Lin <anotherlin@gmail.com> wrote:

First has anyone here built one of Ron Dekker's U-Tracer and what are your
opinions?
I've built the uTracer 3+. If you like building things, especially electronics, then it's a blast.
It's very easy, only a few SMT (inductors, less than 10), other SMTs come pre-soldered.
Kit is complete, parts all provided, high quality (probably sourced from Mouser or Farnell).
PCB is probably from Belgium. There's even a full construction manual.
You will need an 18-20VDC supply, easy to find.

I do have some interest regarding tubes, mainly because of guitar/bass amps.
However, it's not my main topic of interest, and I'm not an expert. So take my opinion for what is worth.

Regarding the capabilities, I think it should be about the same as 570 or 575. But you may not be able to test power tubes.
It's fully software driven, you will need a PC/laptop running Windows. It's RS232 so you'll also need an USB to RS232 (cheap and easy to find).
Some people may prefer one knob/switch = one function instead of clicking around. The 570 really good in that regard.
With a PC, it's easier to take screenshot, or maybe even dump .csv files of curves.
I've not played that much around, trying a few EF86 and 12AX7 around but works well.

Now, a few bad things:
1) The heater supply is not working. It's not a real buck converter (Ronald doesn't claim it), see the schematic for yourself.
It's no big deal as you can use a bench supply instead.
2) There is no case and you have to make all connections yourself. In fact, I'm lazy, so I've used dangling wires.
3) uTracer 3+ may lack power and voltage for some tubes (not an issue for me), uTracer 6 correct that.

Second I've not had the privilege of using a tracer yet,
I was wondering if you could test a tube with various values of cathode
resistors inserted to see
directly the effects of the NFB of the cathode resistor has on a given tube's
curves?
As you do the connections yourself, you can insert any resistor in serie with the cathode.
But may be the easiest and best thing to do, is to contact Ronald Dekker directly. I've talked a few times by email with him, he's very helpful and friendly.





Shaun M
 

On Fri, Aug 27, 2021 at 04:29 PM, David Holland wrote:


I haven't heard if the UT6 has gotten out of "beta" and is officially
on sale yet though
It is; I just finished building and testing V6 and I am very happy with it.

Shaun Merrigan