[sdiy] FET for VCO cap discharge

[Ian Fritz]

Hi JH --

At 03:18 PM 10/22/05, JH. wrote:
>I don't even have a data sheet of the 256 at hand. It was just a desperate
>move to try what I had in storage, and I was surprised that it worked
>(slightly) better than the 4391.

Well, the only data sheet I found is just a 1/2 page table.  Does anyone 
have a more complete data sheet?

>Me too. I'm not a FET expert either. When I looked for a JFET with higher
>specified current rating than the 4391 at one of my local suppliers, I got
>the impression
>it was pretty much what there is. So I'd either go MOSFET or bipolar, or
>parallel JFETs.

Right.  You might look for the 2N5432, spec'ed at 150 mA.  Higher pinchoff 
voltage, though, and more input capacitance.


>The most ridiculous reason (but that's what it was, as un-scientific it may
>sound!) to try the 256 wasn't even the lower price, but that with this flat
>plastic package, I could stick 3 into the solderless breadboard where the
>metal can 4391 would have required 3 more wire connections
>to a second set of contacts. (;->)

Oh well, I'm sure we all work like that!


>Now that contrary to my expectations, that 256 seems to work quite well,
>I just had to blurt it out.

It's good to know.

   Ian