Sunday, 21 October 2018
FTDX101 Direct Sampling SDR?
Yaesu marketing are in full overdrive claiming the FTDX101 is a direct sampling SDR. Sure their display is driven using direct sampling SDR technology, but anything you hear out the radio (the bit that counts?) goes through a mixer to a 9MHz IF then through a roofing filter etc etc. The whole point of direct sampling is exactly what it says on the tin "direct sampling" of the RF from the antenna not of a 9MHz IF with analogue mixing spurii! Same goes for Icom 7300 and 7610. If you want real direct sampling technology "to listen to" get a Flexradio or an Annan. It is really that simple. I hope the market can come up with guidelines on how to properly describe the glut of new architectures coming onto the market. Something like: hybrid SDR - Anything that uses a mixer as part of the receiver chain that eventually produces audio i.e. Icom/Yaesu/Kenwood/Elecraft. SDR - Anything that directly samples (at more than double the input RF) from the antenna i.e. Flexradio/Annan.