2SK117Y Counterfeits?

[EchoWars]

Found what I thought was a decent deal on 50 of the hard-to-find 2SK117Y JFET's (about $18) and ordered them up. They arrived today, and instead of being in the TO-92 case, they are TO-92L, which is strange. On top of that, a quick check of Idss on about 10 units shows variations from about 6.5mA to 21mA! (Specs for the 'Y' variant call for Idss between 1.2 and 3mA).

Any idea of what these might be? I'm ready to send them back to the seller unless I can come up with a use for them, but my gut instinct is to get rid of them as untrustworthy devices.

Pic below shows one of these K117's in the TO-92L case, with an authentic K117GR from Mike at Ampslab below it.

[lineup]

21 mA ??? Can this be one 2SK117?

According to datasheet, the 2SK117 has got max 14 mA.
And this is the BL version.

If they do not cost too much, you could use them as CCS, current sources.
But so many as 50 .. even if price is not very high.

If they are not 2SK117 ... there is no guarantee they can take 50 Volt drain-source.
And who knows how much (or little) DRAIN-SOURCE voltage they actually can take.

[Zen Mod]

fakes , maybe even bipolars .

did you check them with diode test ?

[EchoWars]

Diode and meter test say they are an N-channel JFET.

Lineup...I'm with you on this one. If they aren't what they say they are, then what are they and can you trust them? I say 'no'.

[mlloyd1]

got a friend with access to a curve tracer? they could check a couple and from the results, you might be better able to guess what device you really have ...

that's too bad, sorry for your pain ....

mlloyd1

[EchoWars]

No curve tracer here...I'm simply going to contact the seller and tell them that I cannot trust these devices as I cannot determine what they truly are.

[Lumba Ogir]

EchoWars,
I was wrong, obviously, there exist fake Toshiba JFETs.

[jacco vermeulen]

Ironically, the K117 is one of the rare Japanese parts that is the real deal under several different names.
As in KEC's KTK117, Samsung's KSK117, Fairchild's KSK117 edition comes in a TO92S(mall) package.
Either one costs pennies in each desired grade in these parts, the K117 is still a very popular component.

(well, not exactly rare, quite a few familiar numbers were second source manufactured in Korea in the 1990s, my parts drawers still contain some KTK146/KTJ73 and KTJ72 from that period)

A JFET in a Long Johns TO92 package smells like re-labelled Fairchild parts.

[lineup]

Originally posted by EchoWars
No curve tracer here...I'm simply going to contact the seller and tell them that I cannot trust these devices as I cannot determine what they truly are.

Yes, Echo
This is what I should do, too.
If you ordered 2SK117Y, it is 100% sure you did not get what you wanted.
If there is only one little chance to cancel this buy .. I would do it.

2SK117 is a nice N-JFET. Low noise and high 50Volt VDS.

You have mentioned www.ampslab.com
He has got a more normal price for the GR and BL class:
http://ampslab.com/components_fets.htm
... but at least you get what you should have for your money.

[nelsonvandal]

Who was the seller?

There are so many deals from Southeast Asia on Ebay that seem to be too good to be true, and this proves they probably are as well.

Our main concern are often sound quality, but what about safety? I don't want to see my house burnt down.