the following info is extracted from TRANSISTORES ORIGINAIS - BANCO DE DADOS [Arquivo] - HT Forum
(brazilian, portuguese content)
orientative capacitance
base emitter base collector
Motorola
MJL21193 7 nF 2,1 nF
MJL21194 6,8 nF 2,5 nF
Toshiba
2sa1943 6,1 nF 3,1 nF
2sc5200 13.5 nF 13 nF
Sanken
2sc2922 10.5 nF 6.2 nF
2sa1216 9 nF 3.5 nF
(brazilian, portuguese content)
orientative capacitance
base emitter base collector
Motorola
MJL21193 7 nF 2,1 nF
MJL21194 6,8 nF 2,5 nF
Toshiba
2sa1943 6,1 nF 3,1 nF
2sc5200 13.5 nF 13 nF
Sanken
2sc2922 10.5 nF 6.2 nF
2sa1216 9 nF 3.5 nF
The values posted are informative. Easy accesible by using a tester with capacitance measurement fixture.
This are not the last word in accuracy, -the component is measured in a rough manner, out of the circuit-.
But useful enough for ¨in the field¨ usage, ie, when shopping parts, or when dealing with suspecting ones...
Thanks to this data, I have avoided harm to drivers and circuitry of a nice vintage amp, plus some profane wording...
Now, time to get a refund...
This are not the last word in accuracy, -the component is measured in a rough manner, out of the circuit-.
But useful enough for ¨in the field¨ usage, ie, when shopping parts, or when dealing with suspecting ones...
Thanks to this data, I have avoided harm to drivers and circuitry of a nice vintage amp, plus some profane wording...
Now, time to get a refund...
One of the clues is that the beta ranking mark is not right. Subtle changes in marking are often used to avoid lawsuits ('see, this marking is not the same, therefore we did not attempt to make a fake, just an equivalent').
The one shown by WuYit is what some manufacturers will sell as 'second source', however the specs are only similar, not the same (in particular, current and voltage tend to be the same but capacitances, gain and SOA are not, usually it's recycling older parts such as MJ15003/4).
The one shown by WuYit is what some manufacturers will sell as 'second source', however the specs are only similar, not the same (in particular, current and voltage tend to be the same but capacitances, gain and SOA are not, usually it's recycling older parts such as MJ15003/4).
He confused me. Well, I bought bunch of these SanKen's 2SA1295/2SC3264 from Lily Electronics Salon and haven't found any problems. I even smashed one and he looks exactly as that transistor shown on WuYit's picture. But goddamn paranoia, I thought WuYit knows something we don't. He probably had a bad experience with Electronics Salon? Like I said, goddamn paranoia.
No I believe Electronics Salon made a lot of pictures of what the insides of genuine transistors SHOULD look like. They probably did this because the store is based out of Hong Kong and many people will not trust any eBay store selling transistors based there.
I do not trust HK/China eBay stores myself - I have never used Electronics Salon, but sadly there are just too many chinese/HK sellers on there selling fake devices. It is not worth the risk. I'd rather pay more and get genuine parts than take a gamble.
I do not trust HK/China eBay stores myself - I have never used Electronics Salon, but sadly there are just too many chinese/HK sellers on there selling fake devices. It is not worth the risk. I'd rather pay more and get genuine parts than take a gamble.
Yes, you're right, it's a gamble. But Electronics Salon has a reasonable shipping cost. Well, unfortunately, the fake infestation has spread all over the world. Look at this shop in USA for an example. The Sanken 2SC2921. The word fake is written all over that transistor! He's screaming...I'm fake!
Do they know that they are selling fake parts? 2SC2921 Transistor
An externally hosted image should be here but it was not working when we last tested it.
Do they know that they are selling fake parts? 2SC2921 Transistor
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nice point, wu yit...
...and given the price of semiconductors like the ones depicted here, original manufacturers could go on the expense of provide some kind of decent packaging, with some marking or hologram or whatever...
c´mon, even condoms come with some sort of ¨D.O.¨
all this rambling with fakes **** me off: it seems that the very powerful industry semicon groups (Toshiba, Sanken...) were incapable of develop some sort of easy guideline or method to avoid all the mess...
really a shame: even those bastards counterfeiters are shooting themselves in the arm, because this state of things will retract a lot of people of buying electronic parts because of fear of being cheated... eventually, popular demand will drop to a minimum ...
I dunno.
Today I spent a good time arguing with the seller (an electronic parts shop here en BA) about fakes, ethics and...refunds.
A philistine employee of the shop -surely comissioning on fakes- even dare to argue about the validity of my suspicions, my sources of information etc.
When I showed him the guts of the transistor, he told me: what did you expect to find inside those things?...
we got very close to a tabern scene, with fighting and insults...
finally, I got some original parts in a shop some 50 yards from there...
I measured the items with a cheap multimeter, -using the data posted above-, and now the amp is running fine and dandy... which is nice...
but the bitter incident ruined my day.
...and given the price of semiconductors like the ones depicted here, original manufacturers could go on the expense of provide some kind of decent packaging, with some marking or hologram or whatever...
c´mon, even condoms come with some sort of ¨D.O.¨
all this rambling with fakes **** me off: it seems that the very powerful industry semicon groups (Toshiba, Sanken...) were incapable of develop some sort of easy guideline or method to avoid all the mess...
really a shame: even those bastards counterfeiters are shooting themselves in the arm, because this state of things will retract a lot of people of buying electronic parts because of fear of being cheated... eventually, popular demand will drop to a minimum ...
I dunno.
Today I spent a good time arguing with the seller (an electronic parts shop here en BA) about fakes, ethics and...refunds.
A philistine employee of the shop -surely comissioning on fakes- even dare to argue about the validity of my suspicions, my sources of information etc.
When I showed him the guts of the transistor, he told me: what did you expect to find inside those things?...
we got very close to a tabern scene, with fighting and insults...finally, I got some original parts in a shop some 50 yards from there...
I measured the items with a cheap multimeter, -using the data posted above-, and now the amp is running fine and dandy... which is nice...
but the bitter incident ruined my day.
those are the genuine parts, bought today...
be as it may, I detected minor serigraph differences between the old parts that I´m replacing (1981), and the new ones: for example, the number ¨6¨ is not identical between older and newer parts.
Something lead me to think that interpreting those things as if they were currency, bank notes or old collectible books is not a proper method... At least for now: do you think seriously that any of the manufacturers could guarantee the inmutability of the marking schemes, or the perfection of the lettering, troughout some 30 years in the making of some product?
Not even present US dollars resemble 1980 ones...
be as it may, I detected minor serigraph differences between the old parts that I´m replacing (1981), and the new ones: for example, the number ¨6¨ is not identical between older and newer parts.
Something lead me to think that interpreting those things as if they were currency, bank notes or old collectible books is not a proper method... At least for now: do you think seriously that any of the manufacturers could guarantee the inmutability of the marking schemes, or the perfection of the lettering, troughout some 30 years in the making of some product?
Not even present US dollars resemble 1980 ones...
Attachments
haha!... sorry for the laugh, but... yes, that´s a valid point for all of you living in civilized countries!!!
but here in South America... it´s the jungle!!!!
No Farnell, no Mouser, nada. There are some ¨representative houses¨ scattered around, but they don´t stock a damn thing: all is traded ¨a pedido¨ (on request; and prepaid, of course...)
Too much fooling around for a humble hobbyist, and too much fooling around even for pros, repairmen and designers... It´s a pity.
A good policy for part of the manufacturers would be a welcome feature: even some individual packaging, some holograms, some tips to help in recognizing the merits of the part. At least in high grade items as good power transistors, high spec opamps, etc...
as in the good old times of vinyl and genuine vs. replacement styli...: ¨beware with cheap imitations, blah blah blah...¨... a leaflet, a box...
I think it´s not so expensive... cigarettes at 1 u$s a pack come with decent packaging, and so too many other fungible, non durable stuff. Beer... Candies...
Sometimes it seems that the industry is becoming over-indulgent about the respectability of the goods being produced... they give no way of reassuring for consumers; leaving more room to hackers, counterfeiters and scam...
i think that the point is...
...that we, as individuals, do not have the power required to fight against the cancer of counterfeiting. It´s a furtive , a stealth activity.
We can post pics, chat about it and try to help ourselves as comrades, but...
hidden people in remote cities (like Buenos Aires, haha!), is scraping old items and repackaging them as desirable and sexy stuff...
Hey, but at least, we can demand to original manufacturers some kind of support... Maybe it´s naive, I know... But the big industry is making lots of money selling parts, so a little in return could be given to consumers...
if not so, the viability of all this hobby, metier or whatever will be seriously compromised in the future... a real pity.
...that we, as individuals, do not have the power required to fight against the cancer of counterfeiting. It´s a furtive , a stealth activity.
We can post pics, chat about it and try to help ourselves as comrades, but...
hidden people in remote cities (like Buenos Aires, haha!), is scraping old items and repackaging them as desirable and sexy stuff...Hey, but at least, we can demand to original manufacturers some kind of support... Maybe it´s naive, I know
... But the big industry is making lots of money selling parts, so a little in return could be given to consumers...if not so, the viability of all this hobby, metier or whatever will be seriously compromised in the future... a real pity.
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