[Lowfer] Re: ARGO V1 b134 Questions

[Alberto di Bene]

> Hello The Net:
> 
> any idea what the resolution bandwidth of the various ARGO modes is ?
> 
> full band view
> CW(NDB)
> 3 second dots
> 10    "
> 20    "
> 30    "
> 60    "
> 90    "
> 120 second dots
> 
> Any idea what the equivalent noise bandwidth (ENBW) is, with each mode ?
> 
> Stan, W1LE   FN41sr   Cape Cod, MA

   Stan,

    that version of Argo has the following parameters :

CW (NDB)  S. rate 22050 Hz, FFT len = 2048   Bin size (RBW)  = 10.77  Hz
Full Band S. rate 11025 Hz, FFT len = 4096   Bin size (RBW)  = 2.69   Hz
QRSS3     S. rate  5012 Hz, FFT len = 16384  Bin size (RBW)  = 0.306  Hz
QRSS10    S. rate  5012 Hz, FFT len = 65536  Bin size (RBW)  = 0.076  Hz
QRSS20    S. rate  5012 Hz, FFT len = 131072 Bin size (RBW)  = 0.038  Hz
QRSS30    S. rate  5012 Hz, FFT len = 262144 Bin size (RBW)  = 0.019  Hz
QRSS60    S. rate  5012 Hz, FFT len = 524288 Bin size (RBW)  = 0.0096 Hz
QRSS90    S. rate  5012 Hz, FFT len = 524288 Bin size (RBW)  = 0.0096 Hz
QRSS120   S. rate  5012 Hz, FFT len = 1048576 Bin size (RBW) = 0.0048 Hz

The window used is a Hamming window (will change this in the planned next version)
That planned next version will also abandon the 5012 Hz as sampling frequency, as modern sound cards do not support it 
anymore. The resolution in the waterfall will be improved by the use of a polyphase FFT (as already done in Winrad),
and there will be a substantial decimation before the FFT.

73  Alberto  I2PHD