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arun1969

While Scanning VHF Band (138Mhz to 174Mhz with Step Size 12.5K). Scanner try to tune on every step. while fft data is available for full IBW e.g AirSpy 10Mhz. why can't it jump to next IBW after checking signal in the same.

LunaeMons

Hi @arun1969 can you make a video of the issue so it's absolutely clear what the reported behaviour is?

arun1969

https://github.com/user-attachments/assets/d127097c-7b6c-4184-b0fd-07db45a5eebb Please find attached video recorded from Mobile

LunaeMons

@arun1969 interesting, the step is quite small in that band at 12.5Khz (that's likely a config error?) that is instructing the tuner to do 12.5Khz small steps while taking the full sampling rate snapshot in each small step. you can do larger steps if you have IBW of 10Mhz, like try 7Mhz steps (still you have some generous 30% overlap between FFT snapshots to cater for the extremes of the FFT window not being as usable as the center)

LunaeMons

so the "step" config parameter in the frequency manager entry dictates the actual hw tuning steps, while the "interval" parameter in the scanner module dictate the in-memory FFT slicing for finding signals above the scanner trigger level

LunaeMons

@arun1969 ideally you want to have your step configured to roughly 70% of your IBW and the scanner interval as low as possible (1Khz ideally, the lowest allowed setting), this will make the tuner do tuning steps of 70% of your IBW, while the scanner looks for signals "in memory" by scanning the full FFT in 1000Hz steps

LunaeMons

@arun1969 did these tips help you in any way?

arun1969

Let me check and revert as you suggested.

arun1969

Yes It's working as per your explanation. This could be error from my side about interpreting documentation, if possible make more elaborate. Next question, in case two band are selected for scanner with different step what will be the logic of scanning.

LunaeMons

@arun1969 the step's parameter context stays within each of the scanned Band entries, so it just means that if you have a Step of 7Mhz in Band A, and 2Mhz in Band B: the HW tuner will be instructed to do 7Mhz steps while scanning in Band A, and 2Mhz steps in Band B

arun1969

Do you check your mail, i Have some of IQ file, which can be useful for Digital Radio Decoder.

LunaeMons

hi @arun1969 sorry I checked it now, thank you!