I have a repeater in the neighborhood (Venlo, NL), about 5km distance. I can open it with CTCSS 71.9 Hz.

In SDRangel set a sink device and choose the Hackrf (directly, not via soapy).

Activate an NFM Modulator channel with the following settings:

AFWB = 6kHz

RFBW =10.7kHz

Dev = +_ 5.0kHz

Activate the mike icon

And 71.9Hz CTCSS tone

At the left side I set the freq 145.000 (input repeater)

SR  =  2.4Ms/s

RF  Amp box = ticked on

VGA = 38dB  (no more because of extensive harmonics !)

 

Push the go button (Blue to green)

Check that in the rigt upoper corner of the modulator you see -1dB and the transmit icon (antenna with radiation).

You can use this icon to put the tx on and of.

If on, you are transmitting about +7 dBm, which is about 5mWatt.

Setting up the mic is not easy. but in the end I got modulation and could make a nice QSO.

So, it works,....!