Recently, TenTec announced a new version of the RX320 that has a 12 kHz IF
output suitable for use with DRM software. A couple of days later, there
was an article on the TT website of how to use the RX340 with DRM.
Basically, they say to use USB, adjust the filter to 16 kHz, set the PBT to
2 kHz and use the audio output. I don't have the DRM software yet, but
followed their instructions and using a audio spectrum analyzer, I was able
to see what looks like the DRM data.
I guess I don't understand the difference between IF and AF, especially when
the IF is relatively low (12 kHz). Is the reason the DRM software wants the
IF output just that most receiver audio stages don't pass 12 kHz of audio
bandwidth?
Also, while receiving (but not decoding) the DRM broadcast on the RX320, I
adjusted the PBT and saw no difference in the received signal using the
SpectroGram audio spectrum program. Is the PBT adjustment really needed for
DRM reception?
73,
Mark
|