Sure, sure - the K369 & 170V were definitely genuine (font + test), so I kept those. 
I only returned the 170BL & GR.
Huijzer have a lot of interesting 2Sx transistors in stock, but now I'm hesitant to place another order with them (getting the refund took some effort, and I of course had to ship the fakes back at my expense - I would've gladly destroyed them with me mallet, but it was quite a lot of money for me).
I only returned the 170BL & GR.Huijzer have a lot of interesting 2Sx transistors in stock, but now I'm hesitant to place another order with them (getting the refund took some effort, and I of course had to ship the fakes back at my expense - I would've gladly destroyed them with me mallet
, but it was quite a lot of money for me).
Hi jfetter,
Destroy the fakes before they creep into your projects. I know it seems like a waste, but without knowing what they really are all you have is a bag of liabilities.
The mallet is strangely therapeutic. Give it a try. Not unless you have a vise and want to see if you can squeeze any electrons out.
-Chris
Destroy the fakes before they creep into your projects. I know it seems like a waste, but without knowing what they really are all you have is a bag of liabilities.
The mallet is strangely therapeutic. Give it a try. Not unless you have a vise and want to see if you can squeeze any electrons out.
-Chris
Hi jfetter,
The mallet is strangely therapeutic. Give it a try. Not unless you have a vise and want to see if you can squeeze any electrons out.
-Chris
Another way is to hook them up, increase the Vds until the (not so) magic smoke comes out.
Now that's just plain fun!
You should see what happens if you stick some in a microwave!
-Chris
Very curious what will happen, I have enough fakes, I'll give that a try tomorrow
900 Watt for 3 minutes?
More fake 2SK170BL's?
I bought some SK170BL's from a UK based ebay dealer.
The ammo packaging gave me confidence that they were 'ok' and a cost any faker wouldn't want to incur. However, when they arrived all was not well, the font looks awful. The IDSS comes in around 18-20mA.
The Peak tester in the background gave some fairly close traces for ID vs. VDS, but based on the awful font, the IDSS way out of range, I'm pretty sure these are fakes, anyone disagree?
I bought some SK170BL's from a UK based ebay dealer.
The ammo packaging gave me confidence that they were 'ok' and a cost any faker wouldn't want to incur. However, when they arrived all was not well, the font looks awful. The IDSS comes in around 18-20mA.
The Peak tester in the background gave some fairly close traces for ID vs. VDS, but based on the awful font, the IDSS way out of range, I'm pretty sure these are fakes, anyone disagree?
Attachments
What is the Forward transfer admittance Yfs read? If it's below say 10mS or at about 5mS, then probably, but they could have been mislabeled, could be Vs.
Mad
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It's been confirmed by multiple sources, e.g. the trusted eBay seller alweit, that Toshiba's very old production runs used a different, printed (not laser etched) font - one that, AFAIK, matches what you've got there; see also the attachments.
But your IDSS is indeed way too high...
Attachments
@MadInventor I measured Yfs at about 30 mS - a bit higher than the data sheet value of 22 mS (typical). I didn't measure them all, but with the Idss being consistent I figure the Yfs will be about the same too for the batch (of 12).
@anatech I did the Idss measurements on a simple rig with a fresh 9 V battery (actually 9.5 V), used 3 separate milliamp meters, results were all very similar. IDSS in the range consistent with V grade devices.
Just curious - what don't you like about the Peak instruments? I just got a DCA75, I was proud of it up to yesterday, not so sure now.
@petoluk - your photos are very helpful. I acknowledge that the devices I have are very probably Toshiba originals now, albeit with IDSS out of range.
I will return my 2SK170's to the original dealer and acquire some more elsewhere. I see NicMac has plenty available..
@WalterW. My Idss rig is dead simple, I guess they all are, I measured the Idss current direct from the DMM. Since I wanted extra reassurance, I got a 2nd DMM and used it, similar results, then an old analog moving coil DC ammeter, again similar results. Way too high IDSS.
I packed the units up and was about to send them back. You wrote your message and I had a bad dose of self doubt, so I found a 1 Ω, 1 % resistor and decided to make voltage measurements instead - just to be sure.
Ran the tests again, [insert picture of CV1040 eating humble pie] they test OK. I won't be making low current reading with any of my DMM's again.
Somewhat embarrassed, but they were genuine all along. I looked again really closely with my magnifying glass in direct sunlight, they have not been sanded. For sure the font is not as elegant as some other SK's but as others have shown it is still ok.
Thank you to contributors on this thread, I'd have sent them back without your help.
