diagram for DIY component tester-tracker

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I remember seeing some diagrams for homemade huntron tracker
type devices using one's scope
I can't find the links and don't remember the principles of operation

anyone?

EDIT:
heres what Huntron will tell us

Tracker Signature Analysis

The Tracker works by applying a current-limited AC signal across two points of a component. The current flow causes a vertical deflection of the CRT trace, while the applied voltage causes a horizontal deflection. Together they form a unique V/I signature that represents the overall health of the device under test. Analyzing the signature can quickly determine whether the component is good, bad, or marginal.
 
It is quite simple.

Take for example a transformer with a 6V secondary winding.
Connect one wire to the X or Horizontal input of your scope and also to a probe of some kind.
Now take the other transformer wire and connect it to a resistor, for example 1kohm, and connect it also to the Y or vertical input of your scope.
The other end of the resistor goes to the ground of your scope input and to another probe of some kind.
Set up your scope so that the horizontal sweep is not enabled, but external input is used.
Also adjust Hor and Ver sensitivity for correct size.

The Huntron tracker works on the same basics as described above, but also with other frequencies and sensitivities.
The last one can be easily done by changing the 1kohm resitor to other values.

good luck,

Dick.
 
Thanks Dick,
also found for some reason people call these things an "octopus"

I have settled on using my signal generator for a source and a few hundred ohms across the horizontal inputs (scope probe 10x)

I can then see the effects of different frequencies and gain like the huntron

found I could also use my cheapie LEADER curve tracer but it only
displays one polarity at a time nd I would need to switch constantly
 
Component tester

Hi,
Im a technician from the Caribbean. Im thinking about buying a BK component tester. Would it really make a big difference in troubshooting. I sometimes have as much as 20 power amps to repair in one week.
What would AK techs recommend to repair power amps more efficiently and faster.
I presently use a scope, audio generator, variac, multimeter, dummy loads.
I have never seen any book that teaches advanced pro audio troubleshooting. Most of the troubleshooting books just have basic run of the mill troubleshooting. Nothing unique and advanced.
Anyone can remove every part in a set and test them with a multimeter.
Does anyone know of any modern troubleshooting techniques.
Thanks.
 
I'm used to using the Huntron for all the repair work I do and couldn't do without it anymore.
With it, it is easy to find what is wrong without applying power.
Of course experience is a must.
I guess experience, knowledge and self taught troubleshooting is the technique. With the latter depending on your instruments.
I don't know of any modern techniques, if any.
 
The only thing I can think of that's better is when you also have an identical working unit, to compare with. Then a "tracker"-type intrument (i.e. current vs voltage x-y scope display) can be used to compare the I-V "signatures" at identical circuit points, in the bad and good units.

A simple I-V x-y display circuit is at http://www.repairfaq.org/REPAIR/F_semitest.html#stqdc , which is part of Sam Goldwasser's excellent "electronic repair" website.

My ready-made one is here: http://www.fullnet.com/~tomg/gooteect.htm . If you want to add base/gate staircase capability to a simple I-V display circuit, like that one has, you can just use a 4-bit binary counter IC and have it count from 0 to 16 (or whatever), one step for each sweep. A simple R-2R ladder works well for a digital to analog converter, for the outputs. Add an opamp buffer/amp, and an attenuator, and it's good to go. In my case, I added a voltage-controlled current source, a Howland type, basically an opamp with a small power amp inside the feedback loops, and also made it able to switch to voltage steps, and calibrated both with a step attenuator, and added a switchable inverting stage to have dual polarities. So now it can also display "families of curves" for transistors.

Another useful thing to do, that can save you some time, is to check the ESR (Equivalent Series Resistance) of electrolytic capacitors. If you don't have an ESR meter, you could use a scope and a square wave generator, as described here: http://www.fullnet.com/~tomg/esrscope.htm . It might be worth also trying to add a DC offset capability.
 
Thanks for the usefull information, Tom.

The only thing I can think of that's better is when you also have an identical working unit, to compare with. Then a "tracker"-type intrument (i.e. current vs voltage x-y scope display) can be used to compare the I-V "signatures" at identical circuit points, in the bad and good units.
Yes, this helps alot, but is not the case in many repair jobs where there is no second good unit available.
Here is where the experience helps, as you can often find the same bogey component failing, like electrolytic capacitors, heat dissipating components, drivers, etc.
The ESR meter, as described, looks very interesting and is a good alternative for the Tracker.
 
Advanced amp troubleshooting

IN most cases only one channel is defective, you could use the working ch as a reference. or there is more than one amp of the same type in the shop. You could also make notes of the readings of a good or new amp.
I have, a very long time ago. began to develop my own method of troubleshooting, simply because I could never find a book that teaches advanced techniques. Another thing I want to try is a NON CONTACT INFRARED THERMOMETER LASER TEMPERATURE tester.
I could use this to check the temperature of a component. Something like a magic wand. Just scanning the components. Would that be a dream come true. You just pass a 'magic wand' over a circuit and find the defective components.
Let me know what you guys think.
Knowledge is power.
 
djmiddelkoop said:
Thanks for the usefull information, Tom.


Yes, this helps alot, but is not the case in many repair jobs where there is no second good unit available.
Here is where the experience helps, as you can often find the same bogey component failing, like electrolytic capacitors, heat dissipating components, drivers, etc.
The ESR meter, as described, looks very interesting and is a good alternative for the Tracker.

Too true. But it was handy when I used to buy and resell military surplus test equipment. One time, for example, I bought qty 35 Tektronix 475 oscilloscopes, and used the comparison technique A LOT. Even in that type of situation, though, experience still trumps everything else.
 
Re: Advanced amp troubleshooting

saj888 said:
IN most cases only one channel is defective, you could use the working ch as a reference. or there is more than one amp of the same type in the shop. You could also make notes of the readings of a good or new amp.
I have, a very long time ago. began to develop my own method of troubleshooting, simply because I could never find a book that teaches advanced techniques. Another thing I want to try is a NON CONTACT INFRARED THERMOMETER LASER TEMPERATURE tester.
I could use this to check the temperature of a component. Something like a magic wand. Just scanning the components. Would that be a dream come true. You just pass a 'magic wand' over a circuit and find the defective components.
Let me know what you guys think.
Knowledge is power.

That's an excellent point, about using one channel to compare to another. That was also an extremely-effective technique for certain oscilloscope repairs.

Making repair and measurement notes for certain equipment models is a also good idea. I toyed with making videotapes and/or digital photographs of scope traces for various points, for certain common models of test equipment that I used to refurbish/repair and resell.

I, too, have always wanted to get one of those non-contact thermometers. Mouser.com carries several models. Home Depot stores, here, have some type of those, too, although I don't know the specs. (Or, maybe a cylinder of liquid nitrogen, with a regulator and a small "air mix and spray" wand attachment, would be cheaper than the usual "freeze spray" cans. :)
 
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