Tube Testing For The Masses

[jim]

http://www.orangeamps.com/products/accessories/amplifier-management/vt1000/

Street Price $499.00

[sluckey]

Buy two and cut your testing time in half. 

[sluckey]

Did you look at the tester? It only tests a very short list of tubes. 6AC10 ain't on the list.

[stratele52]

No test for rectifier . I don't know if this tester do really a good job ? Did it test a high voltage like tube work in amp ?

[MaBerY]

I build this kit http://dos4ever.com/uTracer3/uTracer3.html kit for 200 euro and put it in this case

I measures your tubes outside the maximum power curve because it does pulsed measurements
Looks like this on your PC

[jjasilli]

Very cool!   

[DummyLoad]

apologies if this has been posted here before.

http://dos4ever.com/uTracer3/uTracer3.html

his website has some cool-looking spins on modern tube testers built by DIYs.

perhaps this is controller hardware of the tester posted by MaBerY? 

--pete

[stratele52]

apologies if this has been posted here before.

http://dos4ever.com/uTracer3/uTracer3.html

his website has some cool-looking spins on modern tube testers built by DIYs.

perhaps this is controller hardware of the tester posted by MaBerY?  

--pete

Same as MaBerY post few days ago , you did not look at it ?   

[Willabe]

Website says it's limited to 300vdc.

Can you get an accurate trace for a tube that's going to be run at 475vdc with only 300vdc to test with?


          Brad     

[eleventeen]

Pretty darn cool, MaBerY. (And I own a Hickock 6000)

Yes, the 300 volt limitation is...a something. I guess if a tube is bad at 300 volts we'd like not to throw 450 on it....

[Willabe]

No not if it's bad.

About an accurate trace.


        Brad   

[DummyLoad]

apologies if this has been posted here before.

http://dos4ever.com/uTracer3/uTracer3.html

his website has some cool-looking spins on modern tube testers built by DIYs.

perhaps this is controller hardware of the tester posted by MaBerY?  

--pete

Same as MaBerY post few days ago , you did not look at it ?   

apparently not.   

--pete

[PRR]

A tube *tester* is not the same as a tube *tracer*.

For one, the Orange box knows the Right Answers and grades the tube. The tracer just shows plots and the average person won't have a clue what they should look like.

> a tube that's going to be run at 475vdc

A tube that has 475V of B+ will kick-up to 875V when you play LOUD.

So now we want 900V-1000V laying loose on the desk?

*In general*, if a tube seems good to 300V, the higher range will be an extension of the 100V-300V range. The exception would be a near-short in the tube that blocks 300V and arcs-over at 400V, 600V, 800V, whatever. Such an extreme (and uncommon) defect will probably become known in the amp on the first big chord. I can't think of any handyman tester which tests very high voltages. (The tubes ARE tested at the factory with a 1KV jolt to burn-off any sharp points that might arc.)

[stratele52]

A tube that has 475V of B+ will kick-up to 875V when you play LOUD.
 

875 V !!!!!  Where this voltage comme from if B+ is 475 V ?

 B+ is the maximum voltage avalaible in the amp  . If you play loud it go down beacause sag .

[PRR]

> B+ is the maximum voltage avalaible in the amp 

Max steady voltage, yes.

But getting power out means Voltage-Swing.

When you play LOUD, plate goes down to about 75V and up to about 875V every cycle.

[stratele52]

Ok 875 peak to peak .

[MaBerY]

A tube *tester* is not the same as a tube *tracer*.

For one, the Orange box knows the Right Answers and grades the tube. The tracer just shows plots and the average person won't have a clue what they should look like.

> a tube that's going to be run at 475vdc

A tube that has 475V of B+ will kick-up to 875V when you play LOUD.

So now we want 900V-1000V laying loose on the desk?

*In general*, if a tube seems good to 300V, the higher range will be an extension of the 100V-300V range. The exception would be a near-short in the tube that blocks 300V and arcs-over at 400V, 600V, 800V, whatever. Such an extreme (and uncommon) defect will probably become known in the amp on the first big chord. I can't think of any handyman tester which tests very high voltages. (The tubes ARE tested at the factory with a 1KV jolt to burn-off any sharp points that might arc.)

True, but the orange box is limited to a set of predefined tubes. In most music stores and repair shops this will fit nicely and it saves a lot of time and money.
But I have a fair stock of all kinds of oddball tubes and I want to know if it works ok.
I also have a I-177-B tester and MX-949 expantion box, but this thing is not easy to operate. I found a reference for it for more recent type modern tubes not listed in the original manual and it works.
The uTracer is capable of making exact graphs just like the ones in your datasheets and that's fantastic. You can have an exact view of how the tube performes and not just a LED indication of test failure. It also was fun to build and way cheaper than the orange box.

[stratele52]

> B+ is the maximum voltage avalaible in the amp 

Max steady voltage, yes.

But getting power out means Voltage-Swing.

When you play LOUD, plate goes down to about 75V and up to about 875V every cycle.

I am confused, because, when we put caps on the full wave signal, the average voltage goes up, not the peak.  I know voltage spikes occur, but almost doubling every cycle?   I'm really dense. 

Forget peak voltage , not useful for us.

[HotBluePlates]

I am confused, because, when we put caps on the full wave signal ...

PRR isn't talking about rectification.

Output tubes: there's a transformer attached to the plate. Tube draws more current & pulls its plate closer to 0v; during the other half-cycle when the tube draws less current, the OT inductance causes the plate voltage to kick above B+ and approach B+ times 2 (depending on the tube's current swing).

[kagliostro]

A very simple tube tester

http://www.sm7ucz.se/Tetrode%20tester/Tetrode.htm

K

[Sitedrifter]

Sorry for resurrecting this thread but I own the VT1000 by orange and I find it perfect for the average user. I have various power tubes matched by Apex and Eurotubes and the VT1000 shows a match as well.
While you see concise LED output for the matching it still is a great way to test tubes especially for defective out of the box tubes before dropping them into your amp. I am surprised that not much of this tester is written about on forums. I assume due to it's cost and that most tube sellers test and match now so need to own your own tester. For me, it is a great gadget that I enjoy with good results.