Not sure if this is the issue with you, but while trying to set a couple vehicles transmitting VHF AM for a "recover stolen cargo/spacecraft" mission for the Hind using the R-852 Radio Receiver + ARK-U2 Direction finder I notice that;
if you are a RED Coalition Hind;
if the vehicles transmitting are BLUE, you can get a signal on ARK-U2 (and the needle works) but no sound (even with the ARK-U2 switch on COMMS and the radio suite rotary knob on ARK).
if the transmitting vehicles are also RED, you get the signal and the sound (with the ARK-U2 switch on COMMS and the radio suite rotary knob on ARK).
Quati's post in ADF homing / direction finding was marked as the answer