Desired Vs. Actual Parameter Values

Desired vs. Actual in the Receiver Block

When you set mask values for center frequency and tuner gain, the block initially performs some rudimentary checks that the values are scalar and real. If your values pass those checks, you can still provide values that are out of range for the RTL-SDR radio. In that case, the hardware makes a best effort to set the requested value, and reports the actual value in the Device value column of the block mask.

Desired vs. Actual in the Receiver System Object

The System object™ properties always shows the requested values for center frequency, sample rate, and frequency correction. However, due to quantization or range issues, the actual values can differ from your desired values.

For example, h.CenterFrequency displays the requested center frequency set by you. To see the actual center frequency set at the radio, call the info method, r = info(h): r.CenterFrequency shows the actual center frequency. The System object sends the requested values to the radio and reads the actual values back when either the info method is called or when step() is called.

Parameter to Set	Actual Value
h.CenterFrequency	r.CenterFrequency
h.SampleRate	r.SampleRate
h.FrequencyCorrection	r.FrequencyCorrection