Info on transistor testers?

D

Dave

Guest
I am in the market for a transistor testor, but don't know what to look for.
What makes a good transistor testor? Anyone have any recommendations? I
have found one used Supercricket TF30 transistor/FET testor for about
$30.00, and another apparently higher-end unit for $150.00, but have no idea
why one is so cheap and the other is so expensive. (Sorry I can't remember
the make or model of the higher-end unit.) Input is greatly appreciated. I
am just a hobbyist, but I want to keep up the trend I have started of
getting decent equipment rather than cheapest/easiest to find.

Thanks,

Dave
db5151@hotmail.com
 
this may seem a bit expensive on first impression but they realy are the
'dogs bits'.
http://rswww.com/cgi-bin/bv/browse/Module.jsp?BV_SessionID=@@@@0532914198.10
72037371@@@@&BV_EngineID=ccceadckelmlimdcfngcfkmdgkldfhg.0&cacheID=ukie&3249
490834=3249490834&catoid=-99461131
i'm not recommending this specific make/model, there are others out there
but i swear once youve used one of these 'component analysers you wont want
to touch a run of the mill 'transistor tester ever again.
Alan

"Dave" <dbeane@genie.idt.net> wrote in message
news:bs4sb0$jq3@library1.airnews.net...
I am in the market for a transistor testor, but don't know what to look
for.
What makes a good transistor testor? Anyone have any recommendations? I
have found one used Supercricket TF30 transistor/FET testor for about
$30.00, and another apparently higher-end unit for $150.00, but have no
idea
why one is so cheap and the other is so expensive. (Sorry I can't
remember
the make or model of the higher-end unit.) Input is greatly appreciated.
I
am just a hobbyist, but I want to keep up the trend I have started of
getting decent equipment rather than cheapest/easiest to find.

Thanks,

Dave
db5151@hotmail.com
Click to expand...
 
Dave wrote:
I am in the market for a transistor testor, but don't know what to look for.
What makes a good transistor testor? Anyone have any recommendations? I
have found one used Supercricket TF30 transistor/FET testor for about
$30.00, and another apparently higher-end unit for $150.00, but have no idea
why one is so cheap and the other is so expensive. (Sorry I can't remember
the make or model of the higher-end unit.) Input is greatly appreciated. I
am just a hobbyist, but I want to keep up the trend I have started of
getting decent equipment rather than cheapest/easiest to find.

Thanks,

Dave
db5151@hotmail.com
Click to expand...
What to get depends critically on three things:
What's a transistor?
Bipolar?
FET?
SCR?
Diode?
Zener?
Tunnel?
Frequency range?
Current range?
Voltage range?
What do you want to test?
go-nogo?
open?
short?
Breakdown voltage?
Gain at DC?
Gain at high frequency?
Leakage?
Linearity?
Match pairs?
Frequency response
Switching time
Where do you want to test it?
in circuit?
out of circuit?

Statistically, most transistors are either good or
SERIOUSLY BROKE...dead shorted or dead open.
The shorts you can find with an ohm meter.
You can (depending on the surrounding circuit) usually
determine presence of the diode junctions in a bipolar.
Open FETs are a little harder because you have to find a
way to put volts on the gate.
Sometimes a visual indicator is beneficial. Build a current
ramp and use your x-y scope to look at current vs volts.
Think that's how a huntron tracker works.
Anything that requires three probes is problematic unless you
have a prehensile...

If you want to do more than that, you have to pull the transistor
out of circuit. A curve tracer works great for this. You can build
a crude one, but if you want to measure different kinds of devices,
high voltages, high currents, leakages without driving yourself
crazy reconfiguring a jury rigged tester, get a commercial curve tracer.
I've bought Tektroinix curve tracers for as little as $10, but on
ebay you'll pay 15 times that.

If you want to measure high frequency characteristics, you'll need
test fixtures that approximate the application. That's another
big step in cost.

So, if you're occasionally fixing something, use an ohm meter.
Many DVMs also have transistor test sockets that can measure beta
at some low current that you can't control.

If you do a LOT of simple go-nogo testing and time is money, invest
in a simple V-I tester.

If you want to actually TEST transistors, buy a curve tracer.

If you learn how to test 40W 470 MHz transistors out of circuit,
let me know.

Bottom line, most people don't need a transistor tester.

mike

--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
Hmm. The link doesn't seem to work. Could you email it to me at
db5151@hotmail.com?

And I'm not sure what you mean by "dog's bits." Is that good?

Thanks for the input. I might just hold off on the Super Cricket, and get
something more high-end. It does apparently do FET's but I guess that's
about it. Doesn't sound like much tough.

Thanks for your input.

Dave
db5151@hotmail.com

"Alan Springthorpe" <aspringy@blueyonder.co.uk> wrote in message
news:ElnFb.8$Rb.1@news-binary.blueyonder.co.uk...
this may seem a bit expensive on first impression but they realy are the
'dogs bits'.

http://rswww.com/cgi-bin/bv/browse/Module.jsp?BV_SessionID=@@@@0532914198.10

72037371@@@@&BV_EngineID=ccceadckelmlimdcfngcfkmdgkldfhg.0&cacheID=ukie&3249
490834=3249490834&catoid=-99461131
i'm not recommending this specific make/model, there are others out there
but i swear once youve used one of these 'component analysers you wont
want
to touch a run of the mill 'transistor tester ever again.
Alan

"Dave" <dbeane@genie.idt.net> wrote in message
news:bs4sb0$jq3@library1.airnews.net...
I am in the market for a transistor testor, but don't know what to look
for.
What makes a good transistor testor? Anyone have any recommendations?
I
have found one used Supercricket TF30 transistor/FET testor for about
$30.00, and another apparently higher-end unit for $150.00, but have no
idea
why one is so cheap and the other is so expensive. (Sorry I can't
remember
the make or model of the higher-end unit.) Input is greatly
appreciated.
I
am just a hobbyist, but I want to keep up the trend I have started of
getting decent equipment rather than cheapest/easiest to find.

Thanks,

Dave
db5151@hotmail.com
Click to expand...
 
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