[ARC5] BC-453 mods

[Dennis Monticelli]

That makes sense.  The JFET would be the input device and the bipolar is
probably a cascode connection (kinda like a grounded grid amp) to stand off
the higher voltages.

Dennis AE6C

On Sat, Aug 6, 2011 at 1:15 PM, J. Forster <jfor at quikus.com> wrote:

> I've seen two transistor versions, a FET and regular transistor, coupled
> together, used.
>
> -John
>
> ================
>
>
> > FYI.  A JFET is not a triode  It does have a "triode" like region prior
> to
> > pinchoff, but beyond that Vds bias point the current saturates like a
> > pentode.  The pinchoff voltage is low enough that it is rather
> impractical
> > ficult to run it as a triode in most cases.  But it's a good sub for a
> > pentode and you don't need any "screen" voltage.  The biggest limitation
> > is
> > the max operating voltage.
> >
> > Dennis AE6C
> >
> > On Sat, Aug 6, 2011 at 9:50 AM, Kenneth G. Gordon
> > <kgordon2006 at frontier.com>wrote:
> >
> >> Making the 1st IF regenerative in any of the models is easily done,
> >> and makes a big difference for weak signals....not so much for strong
> >> ones.
> >>
> >> Two pieces of #12 TH or THHN (with insulation still on) soldered to
> >> the grid and plate terminals, and a pot in the cathode is all it
> >> takes.
> >>
> >> The main problem I always had when trying to replace tubes with FETs
> >> is that an FET is basically a triode. For multi-grid tubes, this is
> >> often a real problem.
> >>
> >> For triodes, not so much.
> >>
> >> I have a pair of Tubesters here which I took out of a Heathkit VTVM.
> >> As I remember it, one replaced a 6AL5 and the other a 12AX7.
> >>
> >> vy 73,
> >>
> >> Ken W7EKB
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