10 for $5.50 from China:
http://www.ebay.com/itm/10PCS-Transistor-TOSHIBA-TO-92-2SK170-BL-K170-BL-100-Genuine-and-New-/360683877467?pt=LH_DefaultDomain_0&hash=item53fa6f345b

I found some BC337-25s in a US Ebay store, 50 for $3.20, free shipping, so I'm ordering.

That last part tickles me but the first part is only for now since the main manufacturers have closed down those transistors which sucks.

hi Legalizeshemp420,

If you need latest 2SK170 in SMD format SOT-23  .Do search for LSK170 it's the only company which continue the Toshiba J-FET.

Please don't bother or waste your time searching for better ones.I have already tested with over 20 version of J-FET.
As i have previously mention the 2nd best one is 2N3972 (cost lot more around $7 in ebay)which can start osc at 22mV but it's current\load handling is really lousy.

The circuit posted in youtube was my prototype.If you want to improve current handling please connect "low vce drop" 1 npn transistor in parallel with 1x J-JET 2SK170 or LSK170.

Best selection for NPN transistor is ZTX-1047 ,ZTX1048 these if shorted between collector and emitter manually can osc as low as 29mV or 30mV or go for Japanese transistor 2SD1450 45mV which was shown in my older youtube video.

This is the only lowest voltage Joule Thief which exist in youtube and cost less than <$10 or <$5 to make.
If you plan to run on 1XAA (1.5v and below)do change the only resistor to around 22k.

I only reveal the best to public.

Never mind.  Could not get link to work.

Bill

miscopied link?

Not miscopied.  I did it three times and somehow, the link I was looking at and copied and pasted brought me back to OU.com.  I have no idea why.

I just googled the part number and it came up on page 2.  I hope that helps.  Every other page I looked at wanted to "give me a quote".

Bill

http://www.ebay.com/sch/i.html?_nkw=2sk%20170&clk_rvr_id=527380270894&adpos=1o3&MT_ID=70&crlp=21242113238_2416792&device=c&geo_id=10232&keyword=2sk+170&crdt=0


Here is a link to ebay where you can get the 2SK170 which is now called the LSK170.  (I hope this link works)

Bill

***EDIT***  It works!  Mouser shows these as discontinued but, the ebay prices are not that bad it seems.

For prototyping it is fine.  But, to make an ongoing device that can be improved over time and possibly marketed, it sucks.  I ran into the same thing trying to source those flash circuit inverter transformers.  I have over 100 of them now but...no where to get more except one place that wants $8.00 each in 200 quantities.

I am now working on making my own here in house.  I can do it for about $2.00 each I think.  We will see.

Bill

TK:

I must have missed your post because that is what I posted about the 2sk170's.  I should read more and post less perhaps.

Bill

That store says they can supply large quantities of the 2sk170 too. If that's true maybe some JT fanatic should order a couple hundred, just so that they are available for experimenters.

2SK170 is also available from Amazon. But, I just checked and there are only 19 matched pairs left in stock.

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Heyas, xee.  Love your work on YT just wish you had comments enabled and I have been watching them for about 2 years now.

Nice to know Amazon has them but they are dieing out quickly.

Why is it when something wonderful works it ceases to be made when nothing has taken its place?