• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Transistor Testers

>http://www.harborfreight.com/cpi/cta...emnumber=90899

I have much better VOMs, but I still bought 4 to 5l of these to have around. They are small and do the job. I think they are within 5%, which is good enough 99% of the time. I have never used the transitor testing feature though.

>Exactly how do you decide that "I need a piece of test equipment, but my max spending limit is $5.00" ??

Cheap, cheap :)
 
saj888 said:
Avionic, did you repair audio equipment with the Huntron?
Click to expand...
Yes and No , Aircraft electronics(avionics) ,communication and intercommunication ,navigation,etc. and avionic support equipment. Nothing HI-FI- but lotsa things Hi-tech.
 
saj888 said:
Hi,
Is the B&k 540 as good as the Huntron? I bought one recently. I havent used it as yet.
Thanks
Click to expand...
Ahh,no..The huntron I used could test entire circuit boards full of components ie transistors, hybrid IC's, logic,capacitors, resistors. etc.
 
Not being a technician and having problems with my vintage amps first thing I did was purchase a vintage Sencore TR139B Dynamic in-circuit tester. Other than my Fluke it is now my most important hobby tool.

Had never used one before so thank goodness I got the original service manual with it. Used it first on my G-8700DB to test the outputs in-circuit. Had no idea of what Beta / Beta-leakage /hfe and all the other jargon associated with transistor testing was but thankfully the good manual helped.

What was equally challenging was I really had no idea if the Sencore would really work being an E-Pray purchase. As fate would have it, the first three outputs I tested the Sencore would not calibrate. I'm now thinking my Sencore is certainly DOA. Decided to check the remaining output in the right bank before giving up and ended up with calibration.

Back to the manual to decipher readings. It was then I noticed that "No Calibrate = Bad Transistor." Testing the left side and all were good.
To further check the reliability of the Sencore I removed the right side outputs and indeed the Sencore gave same readings as in-circuit. Killed two birds with one stone. Sencore worked and Bad transistors were located.

EchoWars has often pointed us to possible "lazy transistors." I've been able to locate these easily now and replace at leisure as opposed to total failure.
The Sencore does make dynamic AC Beta check on all transistors in or out of circuit. Checks Leakage out of circuit. Checks all diodes in or out of circuit. Matching transistors is a breeze.

I Sencore tested the new Onsemi's upon arrival and they were all close enough for me. On the other hand, the remaining original Toshibas were significantly different. In hind-sight I whish I was more scientific at the time and wrote down exact readings but I, like all others here, was elated that I was able to read, troubleshoot and make my G-8700DB sing again with your and all other contributors help.

As this is the first and only in-circuit transistor tester I have ever used, I am not sure how it stacks up with the rest, especially newer testers, but it surely worked for me.

Good luck,
Dwight
 
You must log in or register to reply here.
Back
Top Bottom