Aufio codec streaming microphone imput

[VLC_Numpty]

Hi Guys, absolute beginner here trying to stream microphone capture to http.
I have connected the headphone out of a small portable radio to the microphone in jack of my laptop and can hear the audio on the laptop via VLC when I select media --> open capture device and select the microphone from the drop down.
When I try to stream the audio to http with "display locally" selected I lose the audio and nothing streams. As I navigate through the stream wizard I don't know which "profile" to select from the drop down menu. I have tried the 4 existing Audio choices (Vorbis OOG, mp3, FLAC and CD) with "activate transcoding" checked but non of these work. Does anyone know what codec / selection I should use or if I need to create a new specific one.
Thanks