[time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Chris Caudle chris at chriscaudle.org
Wed Sep 21 15:17:00 EDT 2016


On Wed, September 21, 2016 1:59 pm, Attila Kinali wrote:
> On Wed, 21 Sep 2016 09:16:18 -0700
  > Dan Rae <danrae at verizon.net> wrote:
  >> Pretty much all there, but the FET is hard to find now.
>
> If you want to build such an amplifier, then the first stage (aka the
> jFET input and the first opamp) is the critical component. There are
> other, more modern descriptions for this kind of application, in case
> you don't want to just replace the jFET by one if its modern cousins.

If you do want to just substitute newer parts into the same style design,
you should be able to get Linear Systems jfets.  They are not as quiet,
but much lower capacitance, so you could put more in parallel to get
reduced noise.

http://linearsystems.com/products_details.php?pr=jfet-amplifiers--duals&pro_id=65

-- 
Chris Caudle




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