Software and hardware option to convert a Standard Model Q-MAC HF-90M HF Military Transceiver to an Advanced Model Q-MAC HF-90M. Replaces standard microphone with a DTMF Desktop gooseneck microphone with Mil-Std Connector (Q-MAC QM4006M).
http://hf-ssb-transceiver.at-communication.com/en/qmac/option_ex_9.html