Alex wrote:
>
> "Patrick Turner" <info@[EMAIL PROTECTED]
> wrote in message
> news:480F3ADE.856061D3@[EMAIL PROTECTED]
> >>
> > But ß cannot be 1.0 where R1 = R2 ( Ri = Rf ).
>
> Well,
> Ian defined beta as Rf / Ri. Within his definition his equation is
correct.
The vast majority of reputable text books define ß as
**the fraction of the output fed back to the input**.
This is a really basic premise which must be clearly understood.
Ian is welcome to re-invent the wheel yet again but maybe he'd find
nobody would take any notice
because they already know they understand the basics about ß.
Perhaps with ß being plain wrong according to the text books,
Ian has arrived at formula that work for him, but him only.
For the rest of us, we might not agree with his formulas.
For myself, I will adhere to the basic definitions that have been used
for
maybe 80 years.
I found the basic formulas used for series voltage FB as in the case
of a conventional amp with GNFB fo the input triode cathode or a plain
old CF
all work fine, but when you try to apply the same formulas to a shunt FB
amp, they don't give the right answers.
What you calculate MUST agree with what you measure, OK!
Patrick Turner.
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