I'm using the RSP1A SDR and I want to understand how to choose the best configuration for receiving a signal of 125 khz bandwidth.
I would like to know if when choosing the option 200 KHz IF bandwidth with 2MSamples/s sample rate:
- we actually receive 2 Mhz of bandwidth and the remaining 900 Khz from both sides of the spectrum are attenuated
- we only receive 200 khz of bandwidth sampled at 2 MSamples/s rate.
Since i want to reduce the sample rate of the captured signal, i also would like to know if
- I only have to downsample (reduce the sample rate by a factor of N) since it is already filtered to a 200 Khz bandwidth
- filter and then downsample as it is usually recommended to avoid aliasing.
Links to the RSP1A technical information : https://www.sdrplay.com/wp-content/uploads/2018/01/RSP1A-Technical-Information-R1P1.pdf and the RSP1A datasheet https://www.sdrplay.com/docs/171113RSP1AdatasheetV1.6.pdf
EDIT for clarification : As shown in the screenshot, for each sample rate (in this case I'm using the minimal allowed value : 2 MSamples/s), we can choose an IF bandwidth equal or less than the chosen sample rate value (so here i can choose between 1536, 600, 300 or 200 KHz).