de 4N1ZM
I added older easier for understanding version of ladder filter
desingn program in file section under 4N1ZM folder.
--- In BITX20@..., "Max" <m_orwell@y...> wrote:
de 4N1ZM
There is two programs and alternative aproach to ladder filter
design.
Since altavista translation can overcame language bariers it is
possible to check this link through systran translation engine.
Program give obvious relation between impedance capacitance and
crystal unit mesurmen tools:
--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:
That is a good starting point but I'd add much has been published
since then on building crystal filters.
Using the series ladder design and the right constants you can
build
USB and LSB filters as well as symetrical. A good source is the
ARRL
publication Experimental Methods in RF Design which devotes a
fair
amount of text to crystal filters and has a good listing of
citings
for further reference.
I've use their techniques to build excellent filters using 6 and
8
crystals with symetrical shapes to greater than 70db and low
ripple.
The gausian to 6db shape happens to sound the best to me for
2.2khz
SSB filters. I'm using a 6 crystal version of same in the first
version of BITx I've built as an transverter IF.
Allison
KB1GMX
