SDRplay Community Forum

I live close to a very strong FM station. I normally use the RSP2 notch filters to prevent interferences. I would like to activate these filters when using dump1090 but it seems there is no option to activate them. Thus I have to use an inline FM filter with the RSP2 which is a bit weird.

Am I right and there is not option? If yes, are there plans to implement this switch ? (the github repository does not show much activity...)

Best

Hi
There is no way that a software filter could be of any use on a signal outside
the maximum 10 MHz bandwidth of the RSP.
And even when it is useful it uses a lot of dynamic range and processing power.
To protect from 100MHz when receiving 1GHz a shorted IGHz quarter wave line
connected with a T adapter on the input is a good start.

I find myself disoriented after reading your response. The AM/FM BC notch filter of the RSP2 is software-selectable but I though it was an 'actual' filter, not a 'software filter' (DSP filter ?)... The RSP2 FM filter is specified as providing >60dB on the range 80 – 100MHz. So I understood it is used to eliminate images outside this band...

It is a hardware filter on the RSP2 that is software selectable and it is enabled in the RSP2 version of dump1090

Best regards,

SDRplay Support

EA3HUF wrote:I find myself disoriented after reading your response. The AM/FM BC notch filter of the RSP2 is software-selectable but I though it was an 'actual' filter, not a 'software filter' (DSP filter ?)... The RSP2 FM filter is specified as providing >60dB on the range 80 – 100MHz. So I understood it is used to eliminate images outside this band...

You are quite right my answer doesn't apply in that case.

sdrplay wrote:It is a hardware filter on the RSP2 that is software selectable and it is enabled in the RSP2 version of dump1090

Thanks, understood.
Joaquin