Welcome to the Chinese Checkers Page of Chuck Adams, K7QO

This page updated Nov 21, 2016.




No, we are not talking about the kids game played with marbles where two or more players move from one side to the another in a race. This page is about measurements to determine the quality of electronic parts, kits and test instruments. Most you can buy on ebay and other sources online. There are unfounded rumors about some of the quality, but there may be some truth. Let's find out.

Transistor Test Equipment

The first thing is transistor test equipment. Cheap from China. Not so cheap from England. Let's compare them.

Now we are going to be like a man with two watches. He will never know what time it is. Unless they are both synced to WWV in Ft Collins, CO, USA. So, I'm going with the instrument that I trust the most. The atlas DCA Pro DCA75 from Peak. Cost is over $170 US and well worth it. I'll let you google for all the nitty gritty.

I have a sample of 100 2N2222A's from the vendor maymii1029 on ebay for $1.37. I'll first start with a sample of 20 of the transistors to begin the analysis. I don't want to spend a month on this little project. I'll leave it up to you to increase the universe of data.

I can do all 100 later. The first question. How do you keep a large set of parts sorted without a lot of effort and expense? Here is my solution. I use a vector board with 15mm standoffs and then bend the leads on the transistors to 0.10" spacing for storage on the board. I'll keep the board in a plastic container that I got from WalMart for $2.00 US. I'll keep these until I'm through with them as test critters and then use them in projects. I'll know they are good by then. I hope. I can dream, can't I?

Here are some photos taken of the setup. The DCA75 has the three leads with clips and I do not want to mess with this many transistors on and off. So. I use a cheap solderless proto board for an Arduino (about a buck US) setup as you see with a three pin 0.10" header for connections. I just insert and remove transistors into the board as I test them and then put them back into the sample in the right place.

  • Vector board and transistors.
  • Bend leads to 0.10" spacing on transistors.
  • The DCA75.
  • Solderless proto board with transistor and leads from DCA75.
  • Transistors ordered on vector board in groups of 5.

    The DCA75 can measure a number of things and with a computer can do some fantastic curve tracing. But, here I am only going to measure h_FE, the DC gain of the transistors. This does not necessarily mean the transistors will work to a very high frequency for RF. We'll measure that later. OK?

    I'll start out slow and just measure h_FE using different instruments and show their results. It's just a start, not the end to end all things. I'll sit at this computer with a 40" monitor and take the data and immediately enter into this page and post as I go. I've got a number of gadgets to use to take data.

    
                DCA75
    xsistor #   h_FE
     ----      -----
      1         278
      2         279
      3         278
      4         278
      5         284
      6         282
      7         270
      8         273
      9         282
     10         286
     11         282
     12         289
     13         298
     14         312
     15         284
     16         286
     17         282
     18         295
     19         282
     20         271
    

    The following meter is a transistor, inductance and capacitance meter. I bought this one in June of 2016 from wishyou-happy on ebay for $10.96 US. My mistake. Look at the photo.

  • Transistor meter model LCR-T3.

    There are four mounting holes, but one is under the display. You do want to mount this meter on standoffs and there is no way to use the fourth hole that is covered up easily. IMHO. I see the newer models are cheaper and all four holes are useful. Here are my measurements along with the previous.

    
                DCA75   LCR-T3
    xsistor #   h_FE     h_FE
     ----      -----    ------
      1         278      287
      2         279      287
      3         278      287
      4         278      287
      5         284      287
      6         282      287
      7         270      287
      8         273      287
      9         282      287
     10         286      308
     11         282      332
     12         289      432
     13         298      287
     14         312      287
     15         284      287
     16         286      432
     17         282      287
     18         295      287
     19         282      287
     20         271      287
    

    So, from the results I can see that the LCR-T3 is on the DO-NOT-BUY list for any one. IMHO. It looks like the numbers are hard coded into the uP. You have been warned. You do get what you pay for.

    For our next instrument I went into the drawer and brought out a Web-Tronics.com MAS830 DMM with transistor h_FE measuring capability. Let's see what it can do. Don't recall the price I paid for this one and I will attempt to google for it later.

  • DMM with h_FE.
    
                DCA75   LCR-T3   MAS830
    xsistor #   h_FE     h_FE     h_FE
     ----      -----    ------   ------
      1         278      287      297
      2         279      287      296
      3         278      287      294
      4         278      287      300
      5         284      287      299
      6         282      287      299
      7         270      287      286
      8         273      287      290
      9         282      287      299
     10         286      308      304
     11         282      332      296
     12         289      432      304
     13         298      287      313
     14         312      287      327
     15         284      287      302
     16         286      432      303
     17         282      287      298
     18         295      287      311
     19         282      287      296
     20         271      287      287
    

    It looks like the MAS830 follows the trend of the DCA75. It is just unknown what the parameters of operation are for the MAS830. We do know what they are for the DCA75 and I have to do a separate report for that info.

    The next transistor analyzer that I have, from days of yore, is an M^3 (pronounced M-cubed). It is no longer manufactured and was a buildathon project at one of the FDIMs at Dayton. Cost over $100 US. It does go through a few screen displays showing data, but I'll just use the h_FE measurement for now.

  • M^3 Semiconductor Analyzer.

    
                DCA75   LCR-T3   MAS830     M^3
    xsistor #   h_FE     h_FE     h_FE     h_FE
     ----      -----    ------   ------   ------
      1         278      287      297      263
      2         279      287      296      262
      3         278      287      294      261
      4         278      287      300      259
      5         284      287      299      267
    
      6         282      287      299      265
      7         270      287      286      254
      8         273      287      290      258
      9         282      287      299      265
     10         286      308      304      270
    
     11         282      332      296      262
     12         289      432      304      270
     13         298      287      313      277
     14         312      287      327      289
     15         284      287      302      267
    
     16         286      432      303      268
     17         282      287      298      265
     18         295      287      311      275
     19         282      287      296      263
     20         271      287      287      255
    

    The next test instrument is one of the cheap (sometimes free) DMM's from Harbor Freight made by Cen-Tech in China. I'll just label this HF DMM.

  • Harbor Freight DMM (HF DMM).

    
                DCA75   LCR-T3   MAS830     M^3    HF DMM
    xsistor #   h_FE     h_FE     h_FE     h_FE     h_FE
     ----      -----    ------   ------   ------   ------
      1         278      287      297      263      300
      2         279      287      296      262      299
      3         278      287      294      261      296
      4         278      287      300      259      294
      5         284      287      299      267      302
    
      6         282      287      299      265      303
      7         270      287      286      254      292
      8         273      287      290      258      295
      9         282      287      299      265      305
     10         286      308      304      270      309
    
     11         282      332      296      262      302
     12         289      432      304      270      310
     13         298      287      313      277      319
     14         312      287      327      289      333
     15         284      287      302      267      306
    
     16         286      432      303      268      308
     17         282      287      298      265      304
     18         295      287      311      275      317
     19         282      287      296      263      301
     20         271      287      287      255      293
    

    Another transistor tester Mega328 ESR meter from vendor frentaly on ebay item number 321963237498 for $13.98 USD. Two photos showing what comes in the package and a reading for a transistor. A very generous meter. :-)

  • Mega 328 ESR Meter.
  • Mega 328 ESR Meter.

    
                DCA75   LCR-T3   MAS830     M^3    HF DMM   Mega328 ESR
    xsistor #   h_FE     h_FE     h_FE     h_FE     h_FE     h_FE
     ----      -----    ------   ------   ------   ------   -------
      1         278      287      297      263      300      394
      2         279      287      296      262      299      394
      3         278      287      294      261      296      361
      4         278      287      300      259      294      394
      5         284      287      299      267      302      433
    
      6         282      287      299      265      303      394
      7         270      287      286      254      292      288
      8         273      287      290      258      295      309
      9         282      287      299      265      305      394
     10         286      308      304      270      309      433
    
     11         282      332      296      262      302      433
     12         289      432      304      270      310      433
     13         298      287      313      277      319      434
     14         312      287      327      289      333      434
     15         284      287      302      267      306      433
    
     16         286      432      303      268      308      433
     17         282      287      298      265      304      433
     18         295      287      311      275      317      434
     19         282      287      296      263      301      433
     20         271      287      287      255      293      309  
    

  • MG328 Meter.

    The following data for the meter in the above photo. Received Nov 28, 2016 from lu_cytime208 vendor on ebay.com.

    
                DCA75   LCR-T3   MAS830     M^3    HF DMM   Mega328    MG328
    xsistor #   h_FE     h_FE     h_FE     h_FE     h_FE     h_FE       h_FE
     ----      -----    ------   ------   ------   ------   -------   -------
      1         278      287      297      263      300      394        287
      2         279      287      296      262      299      394        287
      3         278      287      294      261      296      361        287
      4         278      287      300      259      294      394        287
      5         284      287      299      267      302      433        308
    
      6         282      287      299      265      303      394        308
      7         270      287      286      254      292      288        287
      8         273      287      290      258      295      309        287
      9         282      287      299      265      305      394        308
     10         286      308      304      270      309      433        360
    
     11         282      332      296      262      302      433        308
     12         289      432      304      270      310      433        393
     13         298      287      313      277      319      434        432
     14         312      287      327      289      333      434        432
     15         284      287      302      267      306      433        308
    
     16         286      432      303      268      308      433        332
     17         282      287      298      265      304      433        308
     18         295      287      311      275      317      434        432
     19         282      287      296      263      301      433        308
     20         271      287      287      255      293      309        287
    



    My email address is the usual hiding from Internet bots.

    chuck dot adams dot k7qo at gmail dot com