Radio test channel setting

[kevin seo]

Hello

In the radio test we can set up to 80 channels.

But isn't the table for the channel as follows?

40 channels is 2480MHz, right?
What is the frequency of 80 channels in Hz? Or is there a different way to calculate the channel?

[ketiljo]

It depends how you look at it. The BLE channel mapping goes from 0 to channel 39. The frequency isn't the same. BLE channel 17 is at 2440 MHz.

Now, if you use DTM (direct test mode), which is a Bluetooth specific test mode, it will use the BLE channel mapping. If you use the radio test example, it's a generic radio tool, it will use the frequency directly. Here, channel 40 is at 2440 MHz.

[kevin seo]

Thank you for your answer!

[dev_electronic]

Dear ketiljo, can you please explane it a little bit more? Why isn't the frequency the same? Why are the steps smaller?

In BLE there are 40 different frequencies lets say channels (0 to 39). Why is it possible with the radio test or DTM to select 81 frequencies (Channels from 0 to 80)?

Thanks a lot in advance.