Does reducing sample rate impact reception?

[iceman977th]

Somewhat fairly new to using SDR's, I'm starting to try them out vs. using two-way radios for my railroad feeds. I only need to pick up from 160.215-161.565MHz, around 1.5Mhz of bandwith. I'm using the RSP1B which can receive up to around 10MHz, but in my testing keeping them that wide open also makes them susceptible to interference from NOAA Weather Radio (which of course is 162.55MHz area, not far off)

I've found that reducing the sample rate and adjusting the center frequency limits the amount of bandwith I receive, and it doesn't seem to pick up NOAA Wx radio when most of that channel is out of the spectrum, but I'm curious if reducing the range that much would impact reception at all. I'll probably need to play with it a bit and see how it picks up when it's on site.

 

[PDXh0b0]

Try switching too LIF , center frequency of 160.900 mhz

 

[PDXh0b0]

 

[dave3825]

I only need to pick up from 160.215-161.565MHz, around 1.5Mhz of bandwith. I'm using the RSP1B which can receive up to around 10MHz, but in my testing keeping them that wide open also makes them susceptible to interference from NOAA Weather Radio (which of course is 162.55MHz area, not far off)

What software are you using? Sample rate sets how much spectrum is to be used/seen meaning lowest freq to highest freq. I run my HackRf and Airspy at sample rate of 10mhz and have no issues like you describe.

Bandwidth is how much of the tuned frequency is processed.

161.565 by me is analog narrowband railroad with emission 11K0F3E

The Emissions Designator 11K0F3E signifies a wireless radio which transfers data over a modulated wave using Single analog channel signal. This signal transmits at a 11.0 kHz [11K0] maximum bandwidth .

161.215 is used digitally (P25) in NY and uses an emission of 8K00F1D

The Emissions Designator 8K00F1D signifies a wireless radio which transfers data over a modulated wave using Digital, on-off or quantized, no modulation signal. This signal transmits at a 8.00 kHz [8K00] maximum bandwidth .

So bandwidth setting depends on the signal you are tuning to.

I've found that reducing the sample rate and adjusting the center frequency limits the amount of bandwith I receive, and it doesn't seem to pick up NOAA Wx radio when most of that channel is out of the spectrum, but I'm curious if reducing the range that much would impact reception at all.

If the grey box covers more than the signal, it will pick up neighboring freqs or co channel. If it's too narrow, it will not get enough signal and sound like crap.

Since such a small range of freqs, you can set sample rate to 2.4 which will only display that on the spectrum allowing you easier visuals. You can also run at 10 mhz but makes tuning by clicking on signals more difficult unless your zoomed into the spectrum. Higher sample rates and also slow down pc's that don't have a great cpu and or not a lot of ram.

 

[Unitrunker2]

Somewhat fairly new to using SDR's, I'm starting to try them out vs. using two-way radios for my railroad feeds. I only need to pick up from 160.215-161.565MHz, around 1.5Mhz of bandwith. I'm using the RSP1B which can receive up to around 10MHz, but in my testing keeping them that wide open also makes them susceptible to interference from NOAA Weather Radio (which of course is 162.55MHz area, not far off)

Interference from an adjacent signal may be caused by too much gain.