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VERSION DATE NAME
English 31/10/12
Dipl.-Ing. R.Menn
Page
15
the carrier, again in the lower sideband. Two het tones (3, 4) appear in the upper sideband, one 5kHz away
from the carrier (4).
Again, the RDR54 gives us some options to optimize the reception.
The RTTY signal and the warbling sound can be cut out completely by using the Synchronous detector and
USB as an option. Then we can use the notch filter for the somewhat broader HET tone (3) and narrow the
bandwidth just so that we just cut out the +5 kHz carrier (4).
Alternatively, we can use the DSB mode of the receiver which offers a somewhat better sound and use another
combination of filters/settings to overcome the before mentioned problems.
This time, we use the Double-Sideband mode (DSB) and shift the spectrum so that the RTTY signal’s effect is
eliminated. Then we set the Notch Filter with a 200 Hz width so that it filters out the warbling sound close to the
