Also known as: sample rate

Sample rate is how many IQ samples per second an SDR produces.¹ With complex sampling, the captured bandwidth is approximately equal to the sample rate — an RTL-SDR at 2.4 MSa/s sees about 2.4 MHz at once.

Sample rate sets how often the SDR measures the signal — and how much spectrum it captures at once.

How it works

Higher rates capture more spectrum but produce more data, raising CPU and USB load (and risking dropped samples). Filtering and decimation narrow a wide capture down to one channel.

Relevance to SDR

For trunk-tracking, choose a rate that just covers the channels you follow — not the widest possible span.

Sources

1. Sampling (signal processing) — Wikipedia, on samples per second and the captured bandwidth they represent. ↩

See also

• Bandwidth
• Nyquist–Shannon sampling theorem
• Aliasing
• Decimation
• Analog-to-digital converter (ADC)

Learn it step by step

• Sample rate, bandwidth & Nyquist