Hi Dimitris,
Here i'm also using a AMradiuo IF filter, a mechanical one. There are
available in a German surplus store,
http://www.oppermann-electronic.de/html/body_hf-spezialbauteile.html
FZ-02. Now they cost 6 Euro, i remember they started with 5 EUR ;-)
Anyway cheap i find because they work really excellent and the effort
isn't high to get good results.
I've got this filter curve in a recent measurement:
https://dl.dropbox.com/u/19882028/MF/473%20kHz%20ZF%20Filter%2040%20dB.png
and
https://dl.dropbox.com/u/19882028/MF/473%20kHz%20ZF%20Filter%201%20dB.png
Datasheet: https://dl.dropbox.com/u/19882028/MF/FZ_01_FZ_02.pdf
73, Stefan/DK7FC
Am 09.03.2013 04:52, schrieb Dimitrios Tsifakis:
Hello group,
I apologise if I am stating the obvious, but perhaps this will be of
interest to someone. Old AM radio IF transformers connected back to
back via a tiny capacitor make a simple but effective 475 kHz BPF:
http://people.physics.anu.edu.au/~dxt103/472/rx_bpf/
73, Dimitris VK1SV
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