[hpsdr] Mercury Spurious signals.

[n3evl]

Hi Kjell,

I can confirm the presence of the same two spurious signals on my 
Mercury-based system.  The signal levels appear to be similar to what 
you measured.

The Mercury firmware level is 3.4 as reported in PowerSDR.  I ran these 
tests with an older PowerSDR - OpenHPSDR mRX-FFT v3.0.16 (5/25/13).

73, Pete, N3EVL

On 2/24/2014 6:02 AM, Kjell Karlsen wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi all.
>
> For a long time I have not used my OpenHPSDR rig with Metis, Mercury 
> and Penelope. It seems to be working OK with the latest firmware 
> installed but there are 2 strong spurious signal present on 20 meter 
> that I do not remember having seen before, at least so strong. One is 
> at 14,2058 MHz and the other is at 14,2079 MHz. Without anything 
> connected to the antenna connector the first is -111 dBm and the 
> second is at -122 dBm. With the antenna connector terminated with 50 
> Ohm, the level is -108 dBm and -120 dBm.
>
> I have used a "sniffer" and can positively say it is coming from the 
> top side of Mercury and they are strongest very near the FPGA. I also 
> see the noise increase near the FPGA but that is natural with all the 
> signals present in this chip.
>
> I tried to "sniff" Hermes too but I do not find those signals here, at 
> least they are very weak.
>
> But something must have happened on the way. As far as I remember the 
> two spurs were not present before but I may have forgot it. If so, 
> just blame it on my age!
>
> 73, Kjell
>


 1393286651.0