LimeSDR: NCO problems

[f4exb]

Noticed a few of things:

• The wideband antenna selector does not work. It does seem to turn on the switch in the hardware (deaf).
• The NCO is de-tuned by a change in the sample rate so once you have changed the sample rate you have to switch the NCO off and on else you don't know where you are tuning anymore.
• NCO limits go crazy when the lower limit would be negative i.e. half the sample rate exceeds the LO which can occur when tunig HF. For example: LO at 30 MHz, device to host S/R at 5 MS/s and hardware decimation at 16 yield a S/R at the ADC of 80 MHz so the NCO would be lower limit is -10 MHz (30 - 40).

[f4exb]

Regarding antenna switch it seems it is working actually judging by the calibration output from LimeSuite that is dumped in the console:

Rx calibration using RSSI INTERNAL ON BOARD loopback
Rx ch.A @ 435 MHz, BW: 4.5 MHz, RF input: LNAW, PGA: 11, LNA: 15, TIA: 3
Performed by: MCU

[f4exb]

There is definitely some signal comig in at the higher frequencies: ~1.8 GHz. Bot signals at ~467 MHZ are still pretty weak compared to the same on the "Lo"input. Then I think it is not a problem with the switching but rather with the right impedance for the "Wide" input.

Even the GSM1800 come louder on the "Hi" input than the "Wide" input so quite frankly I would leave that "Wide" input alone.

[f4exb]

Fixed with v3.5.4