SA612AN (NE612) based
direct conversion receiver for
15440 KHz
It's quite simple to produce DRM demonstration
receiver
using SA612AN
double balanced mixer/oscillator IC. Of course the
receiver doesn't give high perfomance results
but under good receiving
conditions it could show quite nice results,
over 25dB SNR is not uncommon.
Sometimes it's doing job well but sometimes it
doesn't work at all.
I'am using 15432 KHz crystal oscillator which
is tuned to 15428 KHz.
Sines 15.440KHz signal is feeded through band-pass
filter and then
it's mixed in SA612 to produce 12 KHz IF. That's
it!
The IF signal is transferred to soundcards Line-in/Mic
connector.
Dream DRM open source software receiver is practical
with this
receiver because it makes possible to chance
center frequency little bit
from 12 KHz. You can find pictures below and
some
screenshots about receiving tests.
[First realisation]
Screenshots from Dream and DRM Software Radio
