This type is working very nice as alternative extra sound device for digital modes. it can work in DVD quality mode as recommended by the WSJT team But i noticed strong sparking type QRM from it at 144 and even stronger at 432 MHz Tried to solve that with ferrite clamps and Aluminium foil without success. At 144 i use the IC706 classic no external preamp 25m H2000 12eM2 at 22m ag. Using no mast amplifier makes my receiving more sensitive for QRM sources down near the receiver i am aware. But I keep in mind that the S/N ratio direct at the antenna clamps can only get worse from that point. The trade off is to amplify the antenna signal to a usable level adding lowest possible extra noise . At the same time keeping the dynamic range and selectivity high enough. The latest HEM Transistors make this easier then ever before. And the digital modes of WSJT instantly measure whether an extra pre-amp is really improving the SNR or not....
Ham radio in JO33hg31 53.15N 6.35E