transistor tester question

[newperson]

Hello,
I like to mess around with old organs that use transistors as dividers.  I have been getting false readings off my meter saying the transistors are fine but they still do not work as a divider.  I am usually able to find them by reading voltage but often I still take them out of circuit to test.

So I have been looking into getting a transistor meter.  Would this allow for a more correct reading then reading just a diode test or the Hfe test within a multimeter?  I will use this for other older items also. 

From searching around a bit I see several different older brands such as B&K, Sencore, Semitron, and RCA.  I also have seen people posting about the Peak DCA55.  This is a much newer model than the first list. 

Does anyone own one of these and would like to report what they use it for and how much they like or dislike the model?  Or any generally suggestions would be welcomed.

Thanks,

[John Lyons]

The Peak DCA55 Identifies, and measures the transistor reguardless of how you hook up the legs
which is pretty usefull. It reads gain as well as leakage and figures the gain minus the leakage.
I love mine.

[darron]

I love my peak! When friends aren't borrowing it...

[newperson]

the Peak seems to be the way to go just because it is new and seems to do more than the older models.  Plus I think it does FETs and Darls also?  What does it read if a transistor is totally dead or shorted?  Also how much did you both pay/ where did you buy at?  I am in the US and see you can order them directly overseas from the maker.

thanks for the comments,

[darron]

Last check ordering them direct looked super cheap, almost wholesale. And I'm in Australia.


It reads all types of FETs and darlingtons. It will also read and notify of a short or resistor junction. Works great with germaniums too!

[tubelectron]

Well,

I think that I will really need to have an accurate look to that that famous PEAK transistor tester that everybody speaks here...

My DIY GX-1814 Q tester is very accurate for bipolar Si and Ge but not "instant-setup" device : it needs external PSU, 2 DMMs...



Can you give me your PEAK model reference numbers ?

A+!

[darron]

this is the guy:


http://www.peakelec.co.uk/acatalog/jz_dca55.html

[tubelectron]

Good ! Thanks for the link, darron...

This little unit will be a perfect mate to my GX-1814 and my DUOYI DY-294 testers. I see that they sell LCR meters too...

A+!

[cthulhudarren]

this is the guy:


http://www.peakelec.co.uk/acatalog/jz_dca55.html

It looks like that for this tester you're only getting the readings on one bias point, 2.5mA. I'd like to be able to check hfe for multiple bias points like say .25mA, 2.5ma, and 10mA.

[tubelectron]

this is the guy:


http://www.peakelec.co.uk/acatalog/jz_dca55.html

It looks like that for this tester you're only getting the readings on one bias point, 2.5mA. I'd like to be able to check hfe for multiple bias points like say .25mA, 2.5ma, and 10mA.

Well, I don't see what you mean by bias points like say .25mA, 2.5ma, and 10mA : is it Ib ? Ic ? Ie=Ic+Ib ?

I have already this one : http://www.dyinstrument.com/duoyi/?q=transistor_tester/DY294 , which works well, but unfortunately doesn't test correctly the Ge Qs Hfe because there is no Ice0 measurement. If you need custom accurate and repeatable tests, then the best would be a custom tester, so that's why I built mine, at least for bipolar Si and Ge low power Qs... But it is not an automated one at all !

A+!

[LucifersTrip]

After I purchased the Peak, I compared it to R.G.'s method and my standard DMM (that doesn't measure leakage).

The biggest disappointment was with vintage silicon.

http://www.diystompboxes.com/smfforum/index.php?topic=91115.0

[tubelectron]

After I purchased the Peak, I compared it to R.G.'s method and my standard DMM (that doesn't measure leakage).

The biggest disappointment was with vintage silicon.

http://www.diystompboxes.com/smfforum/index.php?topic=91115.0

Very interesting discovery, Lucifer Trips... And disapointing too... And in the meantime not so surprising because "it does it all so easily, don't worry" ! C'est ça, ouais !

I was akeen to think that the PEAK DCA-55 would have been taken in fault with the Ge transistors. Inexplicably, that was with Si... reputedly less leaky. But I am not a transistor specialist for having a possible explanation here.

As mention R.G. in your topic, the measurement / identification protocol is undisclosed to the user, which must blindly trust the instrument's indication - I hate this ! That's why I have several tube testers, several transistor tester, and the possibility to built a dedicated bench test if required...

A measurement is worth by the conditions which were applied to. The rest is, at best, estimation, at least, divination !

A+!

[cthulhudarren]

this is the guy:


http://www.peakelec.co.uk/acatalog/jz_dca55.html

It looks like that for this tester you're only getting the readings on one bias point, 2.5mA. I'd like to be able to check hfe for multiple bias points like say .25mA, 2.5ma, and 10mA.

Well, I don't see what you mean by bias points like say .25mA, 2.5ma, and 10mA : is it Ib ? Ic ? Ie=Ic+Ib ?

Ic. The hfe varies based on this and other stuff like Vcb.

[Nitefly182]

The peak is a great tool for preliminary testing of large lots of parts. I find that its really good with matching up germaniums for fuzzes but I still test transistor sets for all my builds in a test rig with the pedal circuit before I install them in a finished pedal.

[tubelectron]

The peak is a great tool for preliminary testing of large lots of parts

Yes - I think that's the way where the DCA-55 takes advantage, due to its ease and speed of use. This would justify to purchase one, but I would be more suspicious about its ability to identify doubtlessly a type of component, according to LuciferTrips' advice. Then for doubtful case, or higher accuracy, I would crosscheck and do complementary tests on other instruments. Now, the DCA-55 may be also induced in identification error by a faulty component : this justifies the crosscheck, then. It's not a bad instrument at all, as it is at least very practical, but I wouldn't trust it as I trust my FLUKE 87-III and 87-V, in their respective measurements.

A+!

[Scott57]

I'm new to pedal building and to this forum, so first off, I'd like to say "Hi!" to everyone here.

Just yesterday morning, I ordered the DCA55 so I found this thread timely, to say the least. I also saw a companion device, a LCR40 for passive components. Does anyone have this one and/or is it worth getting? Right now, I'm using a middle of the shelf Radio Shack DMM to verify resistor values but if the LCR40 is exceptional in function/value I would spring for that, as well. If not, should I also consider getting a DMM with a hFE function, since mine doesn't handle that? Thanks in advance.

[darron]

I'm new to pedal building and to this forum, so first off, I'd like to say "Hi!" to everyone here.

Just yesterday morning, I ordered the DCA55 so I found this thread timely, to say the least. I also saw a companion device, a LCR40 for passive components. Does anyone have this one and/or is it worth getting? Right now, I'm using a middle of the shelf Radio Shack DMM to verify resistor values but if the LCR40 is exceptional in function/value I would spring for that, as well. If not, should I also consider getting a DMM with a hFE function, since mine doesn't handle that? Thanks in advance.

just about any multi meter will be more than enough for measuring resistors. you can get auto-range (highly recommended) meters super cheap now. most meters are usually accurate to +/- 1% or so anyway, so measuring values to the nearest resistor value is no problem.

i wouldn't bother getting a meter with an hfe test section if you're getting a DCA55. they are usually very clams to test and make dodgy/unsure connections. the atlas tester will be 10x better. you won't be second guessing yourself for pinouts too 

[LucifersTrip]

The peak is a great tool for preliminary testing of large lots of parts

Yes - I think that's the way where the DCA-55 takes advantage, due to its ease and speed of use. This would justify to purchase one, but I would be more suspicious about its ability to identify doubtlessly a type of component, according to LuciferTrips' advice.

A+!

Yes, the big failure was identifying vintage silicon (especially PNP for some reason)...though, it was very accurate identifying germanium...and it is very accurate with modern silicon, darlington, fet, etc...

Remember, the other big benefit is that it will identify the emitter, base, collector and anode, cathode for diodes.
(funny, it just helped yesterday...I couldn't understand why my diode clipping fuzz didn't sound good. I re-checked everything, then finally decided to check the diodes with the Peak. It turns out that the marking for the cathode  was actually on the wrong side. I think that was a first for me.)

[tubelectron]

then finally decided to check the diodes with the Peak.

An important question, at least to me : is the DCA-55 able to test the device in circuit (this one being off power), or you must desolder it to test it ? A such feature would be sometimes of a great help to save time while servicing/repairing.

Any experience about that ?

A+!

[LucifersTrip]

then finally decided to check the diodes with the Peak.

An important question, at least to me : is the DCA-55 able to test the device in circuit (this one being off power), or you must desolder it to test it ? A such feature would be sometimes of a great help to save time while servicing/repairing.

Any experience about that ?

A+!

you have to desolder...