--- In [email protected], "Helmuth Jim Meyer" <[EMAIL PROTECTED]> wrote: > > Hi group, has anybody made bad experiences with any spurious singals, > spikes etc. during reception of broadcast or amateur radio stations on > HF with SDR??? > Only the computer normally produces a lot of disturbing signals from > its main osciallator and all the divider stages for all the various > applications..Any reports please ??? > Jim...
Jim, it all depends on the quality of the PC power supply. I have here two PCs, one produces *absolutely* no electrical noise, the other is terrible, and not usable for SDR. But I am sure that when I will substitute the power supply of this PC with a more modern (and better quality) one, all the problems will disappear. Another source of spurs is the local oscillator of the SDR, if implemented with a DDS. Only the very recent DDS like the AD9912 start to be acceptable under this point of view. Products like the AD9954 (much valued by some because it has I and Q outputs) are *terrible*. They produce a forest of spurs, which can only partially be taken care of via software tricks. 73 Alberto I2PHD
