The don't fake JFETs now.......do they?

[Toney]

 What with all the talk of the the end of cheap through-hole JFETs I figured I had better stock up while they are still reasonably cheap. Got myself a range of most-likely parts and decided to get a few hundred 2n5457s and J201s as they are so common for our use. Kind of a lifetime supply. I see that the 5457s are already shooting up in price. The J201's are dearer than they were but not OTT yet.
 I broke with common wisdom and bought the J201's from Ebay (alert1) and China (alert2). Store was "Polida" who seem to have very good feedback. Anyway.... surprise surprise, they don't seem right.
So far I have tested for VGs off which seemed like the simplest quick test as there are not so many Jfets that have such a low parameter. There are right on the borderline of "spec" with about 30% going slightly over the maximum rating of -1.5v.
Its the cases of the transistors that have me really going "hmmmm" though.





The photo shows the Polida one on the left and a regular one from a known source on the right. Both are branded Fairchild.
First thing I noticed when I got the bag was that the Polida ones have a dry sanded look to them. Kind of like auto paint that has been wet and dry sanded. All the regular Fairchild Jfets I have have a nice shiny polished finish. There are other differences too. The case shape is slightly different. The "real" one has a letter code in the circle on the back. Different batches have different letters. The leads are different - the Polida ones flex more easily.
So they are the physical characteristics. I'll do some more testing soon.
So what do you think? Have you seen Fairchild Jfets that look like this?

Possibilities that come to mind:
The Polida ones could be old stock? Different die/factory?
Some unknown part just plain 'ol sanded and branded?

[askwho69]

WTF? J201 is being Fake? the hell... try make some Jfet for dist or any effects that use jfets. try whats the result

[Toney]

 I am wondering a few things:

Would they bother faking Jfets? I mean really they aren't worth much and sit seems like  a huge effort. But then who knows maybe $30 is enough to be bothered in mainland China? Just that these look so messed with, unless others have seen J201s like this?
If the datasheets hows a VGs off of -0.3 to -1.5 and I am getting readings sitting right on the borderline and spilling over a bit (-1.6/7) is that a fail or not?
Can they be close-ish?

Later today I will have a go at testing for drain current (Idss). Any other parameters that can be easily checked?
Hopefully that will reveal more and I can sik PayPal on the bastards if they come up false.

[J0K3RX]

Does anybody know of a good surface mount equivalent to the J201 other than the 2SK208?

[davent]

You can get J201's in surface mount (Digikey show +25k available), why an equivalent?

dave

[J0K3RX]

You can get J201's in surface mount (Digikey show +25k available), why an equivalent?

dave

ha.. missed those? Why an equivalent? Good question, not sure...? I guess because I build a few pedals here and there that use the j201's and don't want to re-engineer them for different jfet's but if you have any pointers or suggestions I'm all ears I am not by any means an expert at this stuff, still learning...

~Jim

[dthurstan]

I bought a dodgy micro SD card from ebay. Lucky the seller was nice about it and emailed saying she had had some compliants and would refund me. I did some research about this problem. What happens is the cards that don't meet quality control targets get chucked in the bin, however this doesn't happen and people take em home and reprogram a crappy 4Gb card to look will a 32Gb card!

Anyway could this be a similar thing, a batch of j201's don't meet the targets and instead of going in the bin go on ebay? Maybe the difference in finish is because they where canned before they could get polished up?

[Mark Hammer]

Naive question, but I seem to recall there being a different J201 pinout, depending on manufacturer (though my memory may be in error).

If one tried testing out JFETs, using an erroneous pinout, what would happen?

[askwho69]

this maybe be a different subject but still in topic some Chinese manufacturers will sell not quality check by the owner and then sell it in a black market for only 30% . . . like some cases you bought in GCenter , Ebay, MFriend a guitar worth $500 then someone in your local guitar store selling  it for $150 and its same item one and both made in china. this is a real story about manufacturers that's selling not quality check, but you will be lucky if you grab the unchecked  item but a passed item "if checked" . and if you bought $500 and saw next month somebody in your local guitar shop selling for $150 what will you feel? and they say that the item was under the table !

[Earthscum]

"THIS WEEKEND ONLY! BLOWOUT PRICES! EPSON PRINTERS STARTING AS LOW AS 10$! GPS UNITS FOR AS LOW AS 5$! GUITARS, AMPS, AUDIO ACCESSORIES! ALL AT BLOWOUT PRICES! THIS WEEKEND ONLY! AT THE PAVILION AUCTION AND REC CENTER OFF THE MAIN HIGHWAY."

Or the guy who swings by and sells you stuff from the back of the van (it's cheaper to sell it at cost than take shipping and restocking cut from their supplier, and most are legit). I got a pair of Acoustic (brand) speakers that are killer... their flaw was that the cabinet was in need of regluing. It looked like they didn't pass because the joints weren't properly glued. What's cheaper than paying a worker to pry a cabinet apart? Sell it as "Direct Factory" item at a discount price. I just used a spring steal shim, popped the corners all apart from the inside and injected glue, put em back together, and killed the neighbors with some killer sound.

[Toney]

 Well, tests are in.
THESE ARE FAKE
I noticed that the last day for resolution on my Ebay account so I got motivated and tested a random selection for Idss using the method for the Fetzer valve. All Aron's and reliable-supplier J201s came in right within target range. These failed. Their current readings were >200% expected. They also have around 30% over the maximum datasheet level for Vgsoff.  So thats two parameters tested and both fail. And... as discussed above the case and makings do not appear correct.
Lesson learned. Ebay + Chinese parts = asking to be reamed.
I knew this of course. Just couldn't believe they could be bothered with all that fiddly re-marking for $30. Guess that buys a lot of dinners over there.

So please take care, especially buying from Ebay!

[deadastronaut]

luckily ive had only good ebay/china dealings...i thought it was risky at the time, but those el cheapo prices just reel you in...

pt2399, mn3007,4047's..all been fine..

i haven't bought j201's from there though...thats sad that anyone would have to fake them really....shame!.

but i guess its luck of the draw with so many sellers out there!!!!..........some good, some badass...

[Toney]

 Yep, me too. Been lucky so far (as far as I know).
It doesn't necessarily mean this seller (Polida) was aware of it either. They have excellent feedback and stock a pretty huge range of parts could have been their suppliers.
I guess we'll see more of this as Jfets go the way of Germaniums.

Just imagine some poor sucker sitting there, remarking J201's one at a time, thinking of the money they will scam...seems kinda ridiculous :p/

[deadastronaut]

Just imagine some poor sucker sitting there, remarking J201's one at a time, thinking of the money they will scam...seems kinda ridiculous :p/

yeah sod that!!

[wilrecar77]

I bought some j201's from tayda and they look and act just like yours. Not trying to knock against tayda though, because in that same order I got some box caps and they're just fine. Just a heads up if anyone wants to buy some j201's from tayda. Luckily, I'm only out $2.50.

[deadastronaut]

i bought j201's from usa (ebay) in the end, it was cheaper than the uk, and they are fine....

[Toney]

  I bought some last year from a guy in the States called dpi4parts - that's one of his in the comparison photo and I still have some from a few years back from Aron's store. Just by chance they are all Fairchild, so I had a solid comparison base.
All the Aron's and dpi4parts ones look the same and came in well within expected spec.

@wilrecar77
If you tested the Tayda ones and they were out of spec, you should let them know. maximum parameters on the datasheet means Maximum otherwise it's not a J201.  I'm sure they will refund you. They are pretty good like that.

[darron]

i bought 1000x from "ebuy4s". they were on a reel in the photo but came in a bag.

the fairchild logo was slightly different. i thought maybe they were from a different manufacture time.

haven't tested... i'll try to make a boogie with them and see what happens.




that's sad news there....


i've had some unfair experiences with china....


mine doesn't have the "N" on the back. probably the same kind.

[Toney]

  The shipping cost registered back to China hardly makes the return worth it in my case but Darron if you bought 1000 I would definitely send them back and sik PayPal on them if they are fake.
The letter code was different on different Jfets but all the "real" Fairchild ones had it. Not sure that is definitive in any way as there could be different dies and factories.

The easiest parameter to test is the Run Off Groove drain current (Idss) method here:

http://www.runoffgroove.com/fetzervalve.html

Arons/dpi ones were in spec as per the datasheet - vastly different with the Polida dodgy-brothers ones.
 
 

[darron]

well... returns are a calculated risk.


i bought some germaniums which were labelled and pictures as one thing, but came as a generic transistor in a different package. different specs. not like the ones i wanted in the photo. i returned them but by the time that i paid the return cost and they took a small percentage for return-handling i didn't even get half the money back. even if you follow all correct protocols it's not "fair", like i said. china can post things to me at about 1/10 the cost of me sending something there.

the seller's free post includes their sale cost too, so they want to recover that.

ask questions. make double sure. still expect the worst.