I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

Thanks,
--
DaveC

This is an invalid return address
Please reply in the news group

On Dec 11, 6:05 pm, DaveC wrote:
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

Not if you buy from a reputable supplier like Farnell, Digikey,
Mouser, Newark etc, or the approved rep for the manufacturer you have
in mind.

Dave.

"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



...... Phil

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



..... Phil





'They' are faking everything now. There have been incidents of caps
being faked too.

On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo
wrote:

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



..... Phil





'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On 11 Dec, 11:25, Spehro Pefhany
wrote:
On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo



wrote:
Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

** Well, I have bought counterfeit BC639s for 30c each *- *they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - * but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.

..... *Phil

'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.

Best regards,
Spehro Pefhany
--
"it's the network..." * * * * * * * * * * * * *"The Journey is the reward"
* * * * * * Info for manufacturers:http://www.trexon.com
Embedded software/hardware/analog *Info for designers: *http://www.speff.com

Do they work?

Leon

On Thu, 11 Dec 2008 04:26:07 -0800 (PST), the renowned Leon
wrote:

On 11 Dec, 11:25, Spehro Pefhany
wrote:
On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo



wrote:
Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

** Well, I have bought counterfeit BC639s for 30c each *- *they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - * but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.

..... *Phil

'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.

Best regards,
Spehro Pefhany
--
"it's the network..." * * * * * * * * * * * * *"The Journey is the reward"
* * * * * * Info for manufacturers:http://www.trexon.com
Embedded software/hardware/analog *Info for designers: *http://www.speff.com

Do they work?

Leon

Yes, but the wiper pressure/torque to move is not as consistent as the
real Japanese ones, and they are at random positions (hand assembly)
as compared to the real ones which come set dead center (machine
assembly). I would never risk shipping them in a product.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Spehro Pefhany wrote:

On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo
wrote:

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



..... Phil





'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.


Can you post a picture of them, and the real Panasonic pots on
news:alt.binaries.schematics.electronic

--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

On Dec 11, 2:05*am, DaveC wrote:
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

Yes, there are counterfeit dies in TO-3 cans that don't even make the
2n3055's loose standards.

I wouldn't think there would be any problem getting real ones from any
domestic distributor, though. Start going to E-bay or a broker and,
well, I'd scratch my head as to why you're going to E-bay or a broker.

Tim.

On Wed, 10 Dec 2008 23:05:25 -0800, DaveC wrote:

I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

I just wonder, why would anyone spec a 2N3055 these days anyway?

Thanks,
Rich

Tim Shoppa wrote in news:64f8a666-439c-4983-a04d-
:

I'd scratch my head as to why you're going to E-bay

I do it at times. It's a gamble, but there are small firms dealing in surplus
bought up as inventory from unfinished commercial projects, failing
enterprise, or even just rich hobbyists who decide thast some kind of
unilateral 'group buy' makes sense. Say they want a few hundred, and have the
buying power to get a discount on thousands, they then sell batches of 50 or
a hundred on eBay till they recover more than they paid, AND have the stock
levels they need for themselves. I wouldn't want to chance a spend on some
expensive part whose behaviour and appearance are easily faked, and where
that part has a high price, but I've scored some good batches of low
ESR tantalum caps on original reels, varistors, and some very nice SMT
LM317MDT regulators, as well as standard LM317T. A couple of hundred voltage
references too. And some very nice 1W Philips 4.9V zener diodes chosen to fit
a tight space, they're tiny SMT parts. The IC's are National Semiconductor
parts mostly. (And a LOT of small SMT resistors and ceramic caps). If they're
fakes, they work damn well, and at the price I got them, I'm not complaining.
No failures yet.

In short, I don't buy the things people want me to buy, as they hold out
impossible promises, I buy those that I want to buy, IF they are there, meet
required specs, and shipping costs are low, and the seller looks good. Hasn't
failed yet. There are at least two or three good sellers like this in
Florida, they seem to like doing this there for reasons I don't know, there
are more than elsewhere. Anyway, I stay with my own requirements, if the
offerings don't fit, then I pay higher if that's what it takes, from closer
to source. I don't rely on this for large sales, just a few that I can
support if it goes wrong. And it hasn't yet.

The best approach to this might be to do it for those parts where you're
developing something and have some parts types you need lots of whatever
you're likely to work on. It will be a LONG time before I have to take the
same risks again on those parts.

On Thu, 11 Dec 2008 19:38:46 GMT, Rich Grise wrote:

On Wed, 10 Dec 2008 23:05:25 -0800, DaveC wrote:

I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

I just wonder, why would anyone spec a 2N3055 these days anyway?

Thanks,
Rich

A bank of them would make a nice electronic load for battery testing.
I have lots of TO-3 mounting hardware around.

"Rich Grise"


I just wonder, why would anyone spec a 2N3055 these days anyway?



** Name a TO3 pack, general purpose, power BJT that is better, cheaper and
readily available.

Bet you cannot.



..... Phil

"Phil Allison" wrote in
:


"Rich Grise"


I just wonder, why would anyone spec a 2N3055 these days anyway?



** Name a TO3 pack, general purpose, power BJT that is better, cheaper and
readily available.

Bet you cannot.



.... Phil




I can't, but at only a tad more (in hundreds at once), there is the 2n3773.
I've seen those a lot, and used them in audio amp repairs, where they worked
fine. I'm not tying to compare quality, just saying they were cheap, and they
were there when I wanted them.

On Dec 12, 1:41 am, "Michael A. Terrell"
wrote:
Spehro Pefhany wrote:

On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo
wrote:

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.

..... Phil

'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.

Can you post a picture of them, and the real Panasonic pots on
news:alt.binaries.schematics.electronic

How about using the web instead so everyone can view them without
issues?
I don't understand why people persist with using
alt.binaries.schematics.electronic

Dave.

Rich Grise wrote:

DaveC wrote:

I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

I just wonder, why would anyone spec a 2N3055 these days anyway?

I haven't looked at the price recently but for a 115W TO-3 npn general purpose
power transistor it may actually be very cost effective.

Beware of the difference between the 2N3055 and 2N3055H.

Graham

Lostgallifreyan wrote:

"Phil Allison" wrote

** Name a TO3 pack, general purpose, power BJT that is better, cheaper and
readily available.

Bet you cannot.

I can't, but at only a tad more (in hundreds at once), there is the 2n3773.
I've seen those a lot, and used them in audio amp repairs, where they worked
fine. I'm not tying to compare quality, just saying they were cheap, and they
were there when I wanted them.

They were a damn sight pricier than 2N3055s I can tell you. I still have part of
a tray of them left over from when I did repairs more often. Actually not a bad
device at all for its day. It's why 800W per channel became a sort of 'standard'
for PA/SR power amplifiers into 4 ohm loads for ages.

Graham

Eeyore wrote in
:

They were a damn sight pricier than 2N3055s I can tell you.

Fair enough. Was just looking at Digikey's 300 just now, looked decent price
to me, but singles shot up to 2x, even 3x.

"Eeysore the Professional LIAR "


They were a damn sight pricier than 2N3055s I can tell you. I still have
part of
a tray of them left over from when I did repairs more often. Actually not
a bad
device at all for its day. It's why 800W per channel became a sort of
'standard'
for PA/SR power amplifiers into 4 ohm loads for ages.


** OK - lets see you list a couple of popular models of audio power amp
that used only 2N3773s for outputs and were rated at 800 wpc into 4 ohms.





...... Phil

I just wonder, why would anyone spec a 2N3055 these days anyway?

Thanks,
Rich

Replacement.
--
DaveC

This is an invalid return address
Please reply in the news group

Beware of the difference between the 2N3055 and 2N3055H.
Graham

Just max voltage, I think...? 60v vs. 100v
--
DaveC

This is an invalid return address
Please reply in the news group

On Thu, 11 Dec 2008 09:41:59 -0500, the renowned "Michael A. Terrell"
wrote:


Spehro Pefhany wrote:

On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo
wrote:

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



..... Phil





'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.


Can you post a picture of them, and the real Panasonic pots on
news:alt.binaries.schematics.electronic

Done:


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Spehro Pefhany wrote:

On Thu, 11 Dec 2008 09:41:59 -0500, the renowned "Michael A. Terrell"
wrote:

Can you post a picture of them, and the real Panasonic pots on
news:alt.binaries.schematics.electronic

Done:


A little fuzzy, but thanks. BTW, you can get better images of small
parts on a flatbed scanner, but you have to lay a white cloth or thick
sheet of paper over it. Its possible that they are old stock, and
someone played with the adjustments to make sure they all turned before
selling them. I've seen some of that style where the plastic degrades
from the wrong lubricant, and they fell apart when you tried to turn
them. The plastic was soft and sticky, under the knob.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

In article .net,
DaveC wrote:

I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

Thanks,

Any gray market part is a risk, especially if it's out of production.
Since 2n3055 is still in production (from ON Semiconductor) you should
be safe buying it from a reputable distributor.

That reminds me of a couple of gray-market horror stories. I had
specified a 18pF, 2%, C0G capacitor for use in a radio circuit. We made
these radios at a rate of about 1000 a week. Naturally, we ran out of
caps and naturally, the buyer had failed to plan sufficient lead time to
replace them. So he crossed his fingers and ordered a couple reels of
caps from a gray market supplier.

A day after they put them on the line, I was greeted by technicians who
wanted me to help figure out what was wrong with the circuit I designed.
It was these caps. Some of them were around 18 pF. They were mixed
values and some were mechanically unstable. Very ugly. I figure they
were floor scrapings from rubber dog crap factory. But somebody had
taken the trouble to put 3000 or 10000 of them on a reel, make a
realistic looking Murata label and sell them for a few bucks on the gray
market.

More recently, I inherited a project that had been designed several
years ago. So it included some unobtainium parts, in particular a
SHC605. That's an obsolete sample-and-hold circuit. Recently, we had a
new build of these boards and most of them didn't work. So we isolated
the problem down to this part, measured its ins and outs and concluded
it didn't work at all. Then I cut one open and found out it didn't even
have a die inside. Almost all of them we had left were like that.
Between the boards these went on and the labor involved, this cost us
several thousand dollars.

Companies should hire hit men to go after these counterfeiters. It'd be
cheaper than accepting their bad parts into our processes.

But anyway, 2N3055 is still in production, so you're in luck.

On Thu, 11 Dec 2008 23:13:26 -0500, the renowned "Michael A. Terrell"
wrote:


Spehro Pefhany wrote:

On Thu, 11 Dec 2008 09:41:59 -0500, the renowned "Michael A. Terrell"
wrote:

Can you post a picture of them, and the real Panasonic pots on
news:alt.binaries.schematics.electronic

Done:


A little fuzzy, but thanks. BTW, you can get better images of small
parts on a flatbed scanner, but you have to lay a white cloth or thick
sheet of paper over it.

Yeah, it was done with an okay camera, but hand-held & no flash,
sorry, not much depth of field either because the lens was wide open.
The parts are 6mm wide.

Its possible that they are old stock, and
someone played with the adjustments to make sure they all turned before
selling them. I've seen some of that style where the plastic degrades
from the wrong lubricant, and they fell apart when you tried to turn
them. The plastic was soft and sticky, under the knob.

Sealed packaging (with printed logo) so nobody played with them
outside of the factory.



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Hugh Gibbons"

Any gray market part is a risk, especially if it's out of production.


** Wrong.

The risk is HIGHEST if the part IS in production and is popular with
repair techs and /or hobbyists.

See this page for a few examples:

http://sound.westhost.com/counterfeit.htm




....... Phil

DaveC wrote:

Beware of the difference between the 2N3055 and 2N3055H.
Graham

Just max voltage, I think...? 60v vs. 100v

I've never seen a 100V Vceo 2N3055. No, it's speed. RCA's original
'Hometaxial' (single diffused) process yielded a durable (large SOA)
design with 800kHz fT, Motorola's epitaxial was less durable but had an
fT of ~ 2.5MHz.

A similar problem existed with the 2N3442. It could cause amplifiers to
be unstable if the wrong 'variety' was sourced. A notorious cause of
problems with kit amplifiers back in the mid 70s.


"Summary:The 2N3055 power transistor was introduced by the Radio
Corporation of America (RCA) in the early 1960s. It was one of the first
silicon power transistors, offered unrivalled second breakdown immunity
and found many applications particularly in audio power amplifiers and
linear power supplies. Other companies tried to copy it with varying
degrees of success: one company acknowledges it now by naming a power
MOSFET after it. We trace its history, manufacture and eventual decline
against pressure from competing technologies. Modern simulation tools
have been used to investigate the operation of the device which
illustrate its good, and not so good, features. We also relate its
geometry to a SPICE model. Neither of these tools would have been
available to the original developers. We propose that this transistor be
given a place in the archives of history, ranked alongside other famous
devices of the 20th century such as the 300B tube."
http://ieeexplore.ieee.org/Xplore/lo...rnumber=960371



"You can build good amps with 2N3055/MJ2955's and they are pretty cheap.

I've built a .01% amp @50W using them which sounds great.

Many people think these are past their sell-by date, but I think that
they are still OK as a starter.

The old hometaxial RCA 2N3055 was slow (800kHz) and had a large gain
variation (non-linearity) ranging between (say) 120 at 100 mA and 30 at
4A. This was a problem in many 1970's amps which did not have enough
gain to linearise the outputs with feedback. For example if your open
loop gain is 2000 and closed loop 30, as defined by the feedback ratio,
the actual gain will be around 29.6. But if the open loop gain changed
to 8000 the closed loop gain becomes 29.92. That represents a distortion
level of 1%. No wonder many amps sounded different. You can't get these
RCA devices anymore, but ST and ON Semi still sell 2N3055/MJ2955's.

So you need a high open loop gain, and you should get good performance.
You can use Miller compensation if you are careful about the input stage
(see tcpip's forum), but JLH's method seems to be better.

The latest 2N3055 from ON Semi is similar, I suspect, to their MJ15003/4
processing. The SOA of the 2N3055 is up to 40V at 115W, and 60V at about
1A which is higher than any previous epitaxial 2N3055. And, they'll
usually be fine up to +/- 38V power supplies for 60W amps, better than
the SOA I have seen for TIP3055/TIP2955.

They have an fT around 2.5 MHz which is similar to MJ15003/4."
http://www.diyaudio.com/forums/showthread/t-93633.html

bottom of page

Incidentally, the Vcer figure of 70V is most appropriate to the majority
of applications.

Graham

Phil Allison wrote:

"Eeysore the Professional LIAR "

They were a damn sight pricier than 2N3055s I can tell you. I still have
part of a tray of them left over from when I did repairs more often.
Actually not
a bad device at all for its day. It's why 800W per channel became a sort of

'standard' for PA/SR power amplifiers into 4 ohm loads for ages.

** OK - lets see you list a couple of popular models of audio power amp
that used only 2N3773s for outputs and were rated at 800 wpc into 4 ohms.

800W both channels.

Graham

"Eeysore"

Phil Allison wrote:

"Eeysore the Professional LIAR "

They were a damn sight pricier than 2N3055s I can tell you. I still
have
part of a tray of them left over from when I did repairs more often.
Actually not
a bad device at all for its day. It's why 800W per channel became a
sort of

'standard' for PA/SR power amplifiers into 4 ohm loads for ages.

** OK - lets see you list a couple of popular models of audio power amp
that used only 2N3773s for outputs and were rated at 800 wpc into 4 ohms.

800W both channels.


** Is that a correction of your error ?



....... Phil

Phil Allison wrote:

"Eeysore"
Phil Allison wrote:
"Eeysore the Professional LIAR "

They were a damn sight pricier than 2N3055s I can tell you. I still
have part of a tray of them left over from when I did repairs more often.

Actually not a bad device at all for its day. It's why 800W per channel
became a
sort of

'standard' for PA/SR power amplifiers into 4 ohm loads for ages.

** OK - lets see you list a couple of popular models of audio power amp
that used only 2N3773s for outputs and were rated at 800 wpc into 4 ohms.

800W both channels.

** Is that a correction of your error ?

It was my error, freely acknowledged. As used in the RSD / Studiomaster 800B and
800C for example. These were only outrated at the time by moving to the new
Hitachi lateral mosfets, hence the very popular 'Mosfet 1000'. I later designed
a 600 wpc amp for them (1200B) using selected (200V) Hitachi devices. The yield
was good enough for it to be an economic choice.

Graham

On Wed, 10 Dec 2008 23:05:25 -0800, DaveC wrote:

I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabeled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?

Thanks,

Yes. ALL components are being counterfeited in China nowadays.

And they are getting better at it by the day. I think they somehow get
into larger manufacturing plants. I have some microprocessors here
that were even lasermarked and were sent to me as free samples. They
(Chinese of course, who else) were probably hoping that we wouldn't
test them.

An example: Motorola. They sold the transistor division to ON
Semiconductor several years ago. And check ebay: new expensive
motorola transistors are offered there, they are ALL fake!

Sometimes there actually is a chip inside, but a small one. So it may
test ok but will be destroyed when you really when them to deliver
power.

Another thing the chinese do is taking out parts out of scrapped
equipment. They clean them, re-solderdip them etc. Often you can't see
it. But the parts are used. They may work, they may not.

And another thing they do is repacking parts that were rejected in
productionlines. Many parts ar made in Asia, the scrap is sent to
certain companies specialized in scrapping. But they just repack them
and sell them as new. Notice that these are rejected and potentially
(in medical equipment etc) dangerous parts!

And what they do too is remarking. They take normal processors and
make a military one of it by remarking them. On your testbench they
will test ok. But at for example extreme temperatures they will fail.
Would you like to be in an airplane controlled by such parts?

One of the causes is, just like with the crisis we have now, GREED.
Companies over here buy that scrap and sell it here to make large
profits. There are several companies in the US that cannot be trusted
anymore.

Stick with reliable ones like RS, Farnell, Mouser etc. That should be
safe.

P.

On Thu, 11 Dec 2008 06:25:52 -0500, Spehro Pefhany
wrote:

On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo
wrote:

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



..... Phil





'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.


Best regards,
Spehro Pefhany

Hi,

Can I have a foto of that? I am collecting data on fake parts.

We are developing good replacement parts, and I am making a list of
fake parts to show my customers. So they know what is out there.

P.

On Thu, 11 Dec 2008 09:41:59 -0500, "Michael A. Terrell"
wrote:


Spehro Pefhany wrote:

On Thu, 11 Dec 2008 02:12:00 -0800, the renowned PhattyMo
wrote:

Phil Allison wrote:
"DaveC"
I need to buy some '3055's. Is there much risk of getting a counterfeit? I
read that because these are so cheap, they are being substituted (and
relabelled) for more expensive transistors. But there's not much profit in
counterfeiting 3055's.

Should I be concerned?


** Well, I have bought counterfeit BC639s for 30c each - they were very
likely reject BC547s relabelled.

The aim of the counterfeiter is sell devices he can get for almost nothing
that near impossible to sell and make a killing by falsely re-labelling
them.

2N3055s are still very popular and so easy to sell - but lots of other
old, oddball TO3 types are not.

Expect fakes to be offered on eBay and elsewhere.



..... Phil





'They' are faking everything now. There have been incidents of caps
being faked too.

I have a bag of 1,000 fake Panasonic trimpots.


Can you post a picture of them, and the real Panasonic pots on
news:alt.binaries.schematics.electronic

hi,

Our provider blocks binary email groups. Can you post them elsewhere?

P.

P. wrote:
On Wed, 10 Dec 2008 23:05:25 -0800, DaveC wrote:



And another thing they do is repacking parts that were rejected in
productionlines. Many parts ar made in Asia, the scrap is sent to
certain companies specialized in scrapping. But they just repack them
and sell them as new. Notice that these are rejected and potentially
(in medical equipment etc) dangerous parts!

And what they do too is remarking. They take normal processors and
make a military one of it by remarking them. On your testbench they
will test ok. But at for example extreme temperatures they will fail.
Would you like to be in an airplane controlled by such parts?


Not sure about Medical; But the MOD and Aviation industries
have strict procedure. Every part can be directly related
back to its point of manufacture - thats why Mil-Spec is so
bloody expensive, I can see it would be tempting financially
for a suppler to trade non-authentic or copy parts but it
would be difficult to reproduce the required history for
such a part to be able to supply it in the first place.

In Aviation every part is in its own bag with a specific
number that points to a huge paperwork trail and when its
fitted to a piece of equipment the paperwork is then
included within the aircraft manual, its not unusual for a
singular aircraft to gave several filing cabinets of
history. I've worked on aircraft communications equipment,
it can 10 minutes to fix the equipment and then another hour
to fill in the paperwork. No Certificated engineer is going
to risk his qualification fitting a part he cannot
substantiate as being authentic with the relevant paperwork,
it just too expensive and takes too long to get the
accreditation in the first place to risk it for a few pounds.