[Aavso-sid-list] VLF/SID monitoring

[Jean-Pierre Godet]

On Thu, 7 Aug 2008, Siddhartha Jain wrote:

> ...
> ... Should I take the feed cable's capacitance into account when adding 
capacitance to the antenna's feedpoint?
   - The answer is no if you have a circuit, in the loop, matching it to 
the characteristic impedance of the coaxial cable (50 ohms I guess) and, 
at the other end of the cable, another circuit to match it to the input 
impedance of the sound card input.
   - If not, the answer is yes.

>
> And what should be the sound card's sampling rate? Speclab displays
> capability up to 192,000 Hertz. Why not use the soundcard at the
> maximum capacity?
> ...
   It depends of your sound card characteristics. If your sound card 
supports higher sample rate than 48,000, why not ? Only using the sound 
card as receiver, with a sample rate of 48,000 you should listen from near 
0 to 24 kHz. In other case (direct conversion receiver, etc...) "you 
should use the lowest possible sample rate allowed by Shannon's theorem... 
Don't use higher sample rate just because your sound card supports them ! 
" (Wofgang Buescher DL4YHF). Ex. : I use some sort of VLF receiver with an 
audio output 300-6000 Hz, then I choose 12,000 as sampling rate.

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