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Patrick
gogowatch_AT_gmail_DOT_com
Please make sure you include your real name and postal address. Else we cannot ship.
Shipment will be registered air. So please make sure someone is there to receive.
Please confirm here after payment is made, so that we know when to check.
Thx,
Patrick
Started the Pioneer project, beginning with the JFET & Transistor matching. Here my results for the 2SK4883 & 2SA1959 HFE matched pairs, not so difficult to get with a quantity of 25of each, and the JFET 2SK209GR IDSS. All my JFET fit within 5 groups of IDSS. I'll run on close IDSS group through my curve tracer to see their transconductance curves, and I'll choose the closest pairs.
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Houston we have a problem! Take a look at my HFE measurement results. Most of the 2SA1312-BL (PNP) are around 481 to 520 HFE, but the 2SC3324-BL (NPN) are rather from 411 to 440 HFE, so no easy HFE matching between NPN and PNP.
Any recommendation, and or comments? Do I have to reorder the transistors and hope for better overlap?
Thanks
SB
Any recommendation, and or comments? Do I have to reorder the transistors and hope for better overlap?
Thanks
SB
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Hi SB,
Well, all these beta numbers are fantasy. Beta changes strongly with temperature, and unless you can keep the transistors at the same specific temperature, beta readings are only extremely approximate. I'll believe the trend, but not the individual readings.
I don't know what to tell you. Without a temperature controlled jig, you can't really do what you are trying to do. This is especially true if you don't do all the measurements at the same sitting away from sunny windows (basement would be best in a dark corner), and you can't breathe on them. It takes extreme care to get closer approximate numbers.
-Chris
Well, all these beta numbers are fantasy. Beta changes strongly with temperature, and unless you can keep the transistors at the same specific temperature, beta readings are only extremely approximate. I'll believe the trend, but not the individual readings.
I don't know what to tell you. Without a temperature controlled jig, you can't really do what you are trying to do. This is especially true if you don't do all the measurements at the same sitting away from sunny windows (basement would be best in a dark corner), and you can't breathe on them. It takes extreme care to get closer approximate numbers.
-Chris
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