Checking a BC548B NPN Transistor?

"nospam"

** Has it got a "diode test " function you can select on the switch ?

If not, it will not test diodes or transistors.

Get a meter that includes a transistor " Hfe " or "beta" test function.

...... Phil

No

I also have a analogue meter should that do it? It has about 4 sets of options with 7 options in each set on a twirly dial should I be choosing the ohms resistance option but what range - 2Kohm or 20Kohm or higher / lower?

TIA

Need a meter that at least tests diodes.

It seems to be a feature packed analogue meter is there a specific icon I should be looking for on the meter for a diode test?

I am confused as the information at

seems to imply you can test without a diode option - you only need resistance? For resistance I have 20MOhm, 2M, 200k, 20k, 2k and 200 options and a beep/continutity test on my analogue meter?

TIA

--|

on mine however?

Do I then just go through each of the six tests at

Many thanks

Give it a try.

I think I have it - I have found pins 1-2 (red-black lead) and 2-3 (black-red lead) conduct to 700mV so I presume that means pin 2 is the B. Is there a method of seeing which is E and which is C or is that an educated guess?

Go here and scroll down to types.

The testing data you have combined with the wiki data should help make clearer how to determine what is the emitter and collector from your meter readings. Your red lead should be on the base for an NPN and will conduct with the emitter and not the collector much like a diode.

Have fun.

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If you click on "For further information please see the transistors page" on the page you gave, you'll find a simple transisitor tester "2. Testing in a simple switching circuit".

Just made the circuit and insert the transistor in the CBE position. As you already known the B, so dont worry about the C & E first. Press the test button, if the LED goes on, you have C on the LED side and E on 0V. If not reverse C & E and try again.

If the LED doesn't lite either way, the transistor is either bad, non NPN or not a transistor.

Allen

Download the datasheet and see the configuration:

gives you a choice of four manufacturer's datasheets.

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Michael A. Terrell
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Shhhhh I'm trying to teach the boy :p

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At least give him the textbook. You can't learn to fish without a hook, and some BAIT. ;-)

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Service to my country? Been there, Done that, and I\'ve got my DD214 to
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Michael A. Terrell
Central Florida

I did, he had some link to checking transistors, I sent him to wiki for pnp an npn bipolar diagrams, showed him where his diode checker setting was on his meter. :p

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That is a start, but the boy needs to learn to read datasheets, and now is as good a time as any! ;-)

Just think of the things I could've done, if the net was around in the early '60s? A tube databook was a month's spending money when I was in Junior High School. Now there is so much good, free information that you couldn't adsorb it all in a lifetime. :(

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Service to my country? Been there, Done that, and I\'ve got my DD214 to
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Member of DAV #85.

Michael A. Terrell
Central Florida

My entrance was around 1972. Tubes still ruled then. Was taken under the wing of a genius with all things tube. They still fascinate me, transistors are so on and off :)

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Some things just can't be done with tubes. The KU band communications system I built that's aboard the ISS, for instance. Even if you could build it and get it into space, you'd need a nuclear reactor to power it. It would take out a lot of square miles, when it's orbit decayed.

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Service to my country? Been there, Done that, and I\'ve got my DD214 to
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Michael A. Terrell
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Have a friend who worked for Ma Bell. He scrapped out many tube powered microwave relay sites and invited me to come load up on what was being tossed. I got a couple pickup loads of copper waveguide, big copper grounding strips with lugs on them, a 6ghz transmitter, all sorts of odd ball tubes and some usable from Western Electric. Hell everything was Western Electric. I was like a kid in a free candy shop.

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Thanks to everyone who has replied. I am really struggling as you can see. I can't believe that all my new BC548B transistors are broken.

Does this seem correct?

C = 4.98V B = 1183mV

With E emitting 615mV

Does not appear to amplifying anything to me? What could I have done wrong?

TIA