You can whip one up very quickly with Elsie. It's a free program and
very simple to use. Get it here along with some other good stuff on
this page:
http://www.tonnesoftware.com/index.html
The freebie student version is very good and will allow you to build 7th
order Cauer (elliptical) filters which will do the job. With the
registered Pro-Lite version you can design 10th order filters and make
an even better filter.
For cores, you can use Amidon T80-2 ($1.20 ea) wound with #20 wire to
make inductors with Q's ranging from about 200 to 270 for inductors of 3
to 8 uH, which is about the range you will need.
I built a 10th order filter designed with this software. It removed all
my intermod problem on 160 meters, even with a radio station 1500 ft
from me.
Jerry, K4SAV
MIKE DURKIN wrote:
> Any one have schematic/values for a AM Brick-Wall Filter??
>
> Or will a open 1/4 pice of coax do ok for high pass ??
>
> KC7NOA
>
>
>
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