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Toshiba 2SK170BL for sales

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spencer

Member
Joined 2004
fetaudio.com
xaudiox, your parts is on the way to you. Thanks.

Note that I have some K369BL and K363BL NOS for sales also.

Price is $5 for 10 pcs non-matched part. Verified gain is 40mS at 5mA on my curve tracer.
 

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kannan_s

Member
Joined 2009
spencer said:
All,

Now I can provide matched quad K170BL/J74BL (K170 x 2 and J74 x 2 pcs) at $5 each. They can be used to replace one K389 and J109. I sort the jfets in 0.2mA each group. Shipping is $3.

Regards,
Spencer
Click to expand...


Hi I sent you an email for 10 sets of these matched quads - for BL grade of k389 - can you let me know how to send you payment - shipping to 18104 in the US
thanks
sk
 
A

AndrewT

R.I.P.
Joined 2004
spencer said:
One quad set is 2 pcs K170BL and 2 pcs J74BL all matched to within 0.2mA.
Click to expand...
that sounds like selecting similar Idss.
That is not the same as matching.
Matching requires that, at the operating current the Vgs is the same, or put that the opposite way for the test, set the Vgs for the DUT pair exactly the same, i.e. connect the Gates and connect the Sources and measure the Drain current both at actual operating quiescent current and over a range of appropriate Drain currents to see if the transconductance of the devices matches.

Simply selecting by Idss is a waste of time, if you plan to use them in LTP configuration.
 
S

spencer

Member
Joined 2004
fetaudio.com
AndrewT

Please read about JFET principle. For same design jfet (same part number) the gm is related to Idss and Vp.

http://www.onr.navy.mil/sci_tech/31/312/ncsr/devices/jfet.asp

To match the Idss is the first step to make your circuit DC bias work. The gm will come to next buy for same part number and same design jfet, the gm is more or less very similar.

Spencer

By the way, the price of J74BL is $6 for 4 pcs no matter you want them match Idss or not.
 
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