Like the SECO 250, and the EICO 685, this can test devices in or out of circuit.
#TRANSISTOR TESTER DCA55 MOD#
I plan to restore this to its original condition, and then try to add a mod to closely mimic the 5V, 5A Beta test for power transistors used by the manufacturers. The 22.5-volt battery is still available but a modification must be made to the battery holder since the original was a NEDA 420. This device uses a bank of "C" cells to provide 1.5, 3, or 4.5 volts for the collector voltage, plus a 22.5 volt "B" battery. The 870 is powered not only by the AC line but it also needs a couple batteries. Their 870 series testers almost certainly hold the number 1 spot. This is probably the second most complicated transistor tester ever sold. Like Hickok tube testers, Hickok transistor testers tend to be complicated, and this one is no exception. The"C"-cell boxes were so corroded they were worthless. It was in good condition, but the battery boxes and the mounting plate had some rust. This in yet another of my eBay acquisitions. The DCA75 tests at the lowest voltage of all my testers, and then extrapolates curves based on the principle that the gain of a silicon junction is fairly linear, so after a certain voltage and current level, the gain will be uniform up to the point of junction failure.įor those of you who just want something simple, cheap, durable, and very effective, skip down to "The King of Simple - DROK"
#TRANSISTOR TESTER DCA55 PC#
Step 1 is to test a group of transistors using my PEAK DCA75 analyzer with PC graphing and create curve tracings with that. Can all the testers agree on things like gain (hFE)? That's what I plan to find out.
That high current doesn't make sense to me, but that's what their specs claim. The factory tests many power transistors like the MRF-485 at 5 volts, and 5 amperes. Some test at low voltages and currents, and others use as much as 4.5 volts. In this section, I will set forth on a quest to find the Holy Grail of testers. Transistor testers are like tube testers - every tech needs one, and some need five or six. More to come on this device and the others. However, I haven't found a way to make it show the regulated voltage.
It DOES have the capability of testing Zener diodes up to 30-volts. But that's only for charging the battery. I thought it would have something different because it has such great reviews, and it had a micro-USB port. NOTE: I just purchased the new, popular Multi-Function Tester-TC1.
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