Rohm 2N4403s - I'm Even More Convinced They're Cheap Knockof

  • Thread starter Watson A.Name - "Watt Sun
  • Start date
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Watson A.Name - "Watt Sun

Guest
I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
On Wed, 31 Dec 2003 10:41:02 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?
Click to expand...
Any beta bin markings on them?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
On Wed, 31 Dec 2003 11:20:22 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

In article <1g66vvoji9ifd3krgs4bt9i69dh9b2nbgn@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat mentioned...
On Wed, 31 Dec 2003 10:41:02 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?

Any beta bin markings on them?

Each transistor is marked:

R 2N
4403
E B C

Where the R is the logo. The tape they come on is unmarked.
Click to expand...
Any markings or colored dots on the back?

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
In article <1g66vvoji9ifd3krgs4bt9i69dh9b2nbgn@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat mentioned...
On Wed, 31 Dec 2003 10:41:02 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?

Any beta bin markings on them?
Click to expand...
Each transistor is marked:

R 2N
4403
E B C

Where the R is the logo. The tape they come on is unmarked.


Best regards,
Spehro Pefhany
Click to expand...
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
"Watson A.Name - Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in
message news:MPG.1a5cc0f351af6eb0989ae2@news.dslextreme.com...
In article <1g66vvoji9ifd3krgs4bt9i69dh9b2nbgn@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat mentioned...
On Wed, 31 Dec 2003 10:41:02 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?

Any beta bin markings on them?

Each transistor is marked:

R 2N
4403
E B C

Where the R is the logo. The tape they come on is unmarked.


Best regards,
Spehro Pefhany
Click to expand...
According to the graph in my old Motorola transistor manual, the normalized
DC gain (at 25C ) slope is very gradual, peaking at about 20ma and
decreasing back to unity gain (normalized) at about 150ma. I read the chart
as saying that if the gain at 1ma = 100, and at 10 ma it's140, then it will
gradually decrease to 100 @ 150ma. If you are suspicious of your
transistors, why not set up a test and measure the gain at 100ma? That
would remove all doubt.
--
Tweetldee
Tweetldee at att dot net (Just subsitute the appropriate characters in the
address)

Never take a laxative and a sleeping pill at the same time!!
 
In article <7m86vv0iu6folki3hhbgbq86gktj038lbu@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat mentioned...
On Wed, 31 Dec 2003 11:20:22 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

In article <1g66vvoji9ifd3krgs4bt9i69dh9b2nbgn@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat mentioned...
On Wed, 31 Dec 2003 10:41:02 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?

Any beta bin markings on them?

Each transistor is marked:

R 2N
4403
E B C

Where the R is the logo. The tape they come on is unmarked.

Any markings or colored dots on the back?
Click to expand...
No markings or colorings. The "bellybutton" dimple cast into the back
has some characters cast into it. Many have nothing, but some have
two symbols such as: R3, I6, L4, O8, O5, L5, and some symbols look
like they may be Japanese. Many of these have an overbar or an
underbar on the first symbol. From what I've seen on the surface
mount devices data sheets, this may be a date code.


Best regards,
Spehro Pefhany
Click to expand...

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
On Wed, 31 Dec 2003 10:41:02 -0800, Watson A.Name - "Watt Sun, Dark
Remover" <alondra101@hotmail.com> said...
I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?


I wouldn't be surprised. From the rare occasions I've had to go to
Click to expand...
RS, I've acquired a few bags of their resistor assortments. So far,
every one that I've measured was right on the edge of the tolerance
range.
--
Best Regards,
Mike
 
"Active8" <mTHISREMOVEcolasono@earthlink.net,invalid> wrote in
message
news:MPG.1a5d4b34105a3d829897e2@news.east.earthlink.net...
: On Wed, 31 Dec 2003 10:41:02 -0800, Watson A.Name - "Watt Sun,
Dark
: Remover" <alondra101@hotmail.com> said...
: > I bought some 2N4403s with the R logo on them, all of them
still on
: > tape. Cost just a few dollars on Ebay. Well, I'm even more
convinced
: > they're cheap knockoff parts, or they've been culled. I
pulled ten of
: > them off the tape and tested them for beta at 10 mA, with
both my ol'
: > Heatkit IT121 transistor checker, and a cheap DMM. All of
them had
: > betas in the low 100s, mostly around 110 or 120, with one
around 140.
: > This is at 10 mA, at about a volt, as the test specifies in
the data
: > sheets. The Philips and On Semi data sheets guarantee 100
min at 10
: > mA, and 100 to 300 at 150 mA. Well, since the beta falls off
as the
: > current increases according to the chart in these data
sheets, it
: > seems to me that it's likely that the betas wouldn't make it
to 100 at
: > 150 mA. If so, they would be barely borderline.
: >
: > All this, and the earlier discussion leads me to believe
they're cheap
: > knockoff parts, or seconds, culled from a large batch. Even
so, they
: > were put on tape for sale. Who knows?
: >
: >
: I wouldn't be surprised. From the rare occasions I've had to go
to
: RS, I've acquired a few bags of their resistor assortments. So
far,
: every one that I've measured was right on the edge of the
tolerance
: range.

Thanks for bringing that up Mike. I thought
there was something wrong with my DMM. Seems
I found the same to be true, and mostly on
the low side too.

Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy4SPAM6pa@comXcast.net
Remove - SPAM and X to contact me



---
This email ain't infected, dude!

Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.556 / Virus Database: 348 - Release Date: 12/27/03
 
On Wed, 31 Dec 2003 21:12:43 -0500, willy46pa@comcast.net said...
"Active8" <mTHISREMOVEcolasono@earthlink.net,invalid> wrote in
message
news:MPG.1a5d4b34105a3d829897e2@news.east.earthlink.net...
: On Wed, 31 Dec 2003 10:41:02 -0800, Watson A.Name - "Watt Sun,
Dark
: Remover" <alondra101@hotmail.com> said...
: > I bought some 2N4403s with the R logo on them, all of them
still on
: > tape. Cost just a few dollars on Ebay. Well, I'm even more
convinced
: > they're cheap knockoff parts, or they've been culled. I
pulled ten of
: > them off the tape and tested them for beta at 10 mA, with
both my ol'
: > Heatkit IT121 transistor checker, and a cheap DMM. All of
them had
: > betas in the low 100s, mostly around 110 or 120, with one
around 140.
: > This is at 10 mA, at about a volt, as the test specifies in
the data
: > sheets. The Philips and On Semi data sheets guarantee 100
min at 10
: > mA, and 100 to 300 at 150 mA. Well, since the beta falls off
as the
: > current increases according to the chart in these data
sheets, it
: > seems to me that it's likely that the betas wouldn't make it
to 100 at
: > 150 mA. If so, they would be barely borderline.
:
: > All this, and the earlier discussion leads me to believe
they're cheap
: > knockoff parts, or seconds, culled from a large batch. Even
so, they
: > were put on tape for sale. Who knows?
:
:
: I wouldn't be surprised. From the rare occasions I've had to go
to
: RS, I've acquired a few bags of their resistor assortments. So
far,
: every one that I've measured was right on the edge of the
tolerance
: range.

Thanks for bringing that up Mike. I thought
there was something wrong with my DMM. Seems
I found the same to be true, and mostly on
the low side too.
Click to expand...
So you trust the meter again, I hope. I have no reason to suspect
my meter, but I think I'd do well to get some calibration refs
around here.

Your reader quotes ugly. What's your word wrap set at? I'm at 68.

HNY and good health in '04
Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy4SPAM6pa@comXcast.net
Remove - SPAM and X to contact me



---
This email ain't infected, dude!

Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.556 / Virus Database: 348 - Release Date: 12/27/03
Click to expand...
--
Best Regards,
Mike
 
In article <9KGIb.263743$Ec1.9101393@bgtnsc05-
news.ops.worldnet.att.net>, dgmason99@att99.net mentioned...
"Watson A.Name - Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in
message news:MPG.1a5cc0f351af6eb0989ae2@news.dslextreme.com...
In article <1g66vvoji9ifd3krgs4bt9i69dh9b2nbgn@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat mentioned...
On Wed, 31 Dec 2003 10:41:02 -0800, the renowned Watson A.Name - "Watt
Sun, Dark Remover" <alondra101@hotmail.com> wrote:

I bought some 2N4403s with the R logo on them, all of them still on
tape. Cost just a few dollars on Ebay. Well, I'm even more convinced
they're cheap knockoff parts, or they've been culled. I pulled ten of
them off the tape and tested them for beta at 10 mA, with both my ol'
Heatkit IT121 transistor checker, and a cheap DMM. All of them had
betas in the low 100s, mostly around 110 or 120, with one around 140.
This is at 10 mA, at about a volt, as the test specifies in the data
sheets. The Philips and On Semi data sheets guarantee 100 min at 10
mA, and 100 to 300 at 150 mA. Well, since the beta falls off as the
current increases according to the chart in these data sheets, it
seems to me that it's likely that the betas wouldn't make it to 100 at
150 mA. If so, they would be barely borderline.

All this, and the earlier discussion leads me to believe they're cheap
knockoff parts, or seconds, culled from a large batch. Even so, they
were put on tape for sale. Who knows?

Any beta bin markings on them?

Each transistor is marked:

R 2N
4403
E B C

Where the R is the logo. The tape they come on is unmarked.


Best regards,
Spehro Pefhany

According to the graph in my old Motorola transistor manual, the normalized
DC gain (at 25C ) slope is very gradual, peaking at about 20ma and
decreasing back to unity gain (normalized) at about 150ma. I read the chart
as saying that if the gain at 1ma = 100, and at 10 ma it's140, then it will
gradually decrease to 100 @ 150ma. If you are suspicious of your
transistors, why not set up a test and measure the gain at 100ma? That
would remove all doubt.
Click to expand...
With the DMM, I can't adjust the current; it's probably only a mA or
less. But the Heathkit tester was made for up to a amp. But it
suffered corrosion damage to the battery holder contacts when a
battery leaked, so I did the earlier test with alli clips connecting
the battery holder contacts to a pair of AA cells. At 100 mA, this
wasn't giving stable readings, so I did the earlier tests at 10 mA.

So after reading this, I took the keystone battery holder out and
replaced the contacts with a 4-40 screw, nut and nylon spacer from a
transistor mounting kit. The old contact crumbled when I tried to
clean off the corrosion, so it was the problem.

I took the ten 2N4403s and retested at 100 mA, and they did better at
100 mA than at 10 mA. Instead of only 110 to 120, they showed betas
of around 140 at 100 mA. So apparently the Rohm 2N4403 doesn't
conform to the graph that Philips shows in their data sheet, and the
beta does increase at currents above 10 mA. Rohm's specs are the same
as the Philips data sheet, so I thought it was safe to assume that the
performance would be the same. I also checked the Fairchild data
sheet and it also shows the graph without a 'hump' like the Philips
graph.

Well, I gotta watch the Rose Parade so I'll followup later. ;-)

Never take a laxative and a sleeping pill at the same time!!
Click to expand...
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
On Thu, 1 Jan 2004 08:32:29 -0800, Watson A.Name - "Watt Sun, Dark
Remover" <alondra101@hotmail.com> wrote:

[snip]
I took the ten 2N4403s and retested at 100 mA, and they did better at
100 mA than at 10 mA. Instead of only 110 to 120, they showed betas
of around 140 at 100 mA. So apparently the Rohm 2N4403 doesn't
conform to the graph that Philips shows in their data sheet, and the
beta does increase at currents above 10 mA. Rohm's specs are the same
as the Philips data sheet, so I thought it was safe to assume that the
performance would be the same. I also checked the Fairchild data
sheet and it also shows the graph without a 'hump' like the Philips
graph.
Click to expand...
It is normal for transistors to have a beta "peak", an intermediary
current at which beta is maximum. Above and below this value beta
drops off.

You can amuse (and educate) yourself by simulating beta versus current
varying model parameters ISE (base-emitter "leakage") and IKF (current
crowding).

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
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