Digital Modes Interface question I'm wondering what the practical advantages are (if any) of commercial digital mode interfaces with their own sound card, such as the SignaLink, RIGblaster, RASCAL, etc. For PSK31, etc., all I have here between my computer (using Fldigi) and my Icom transceivers is a very simple homebrew interface: It uses two audio transformers and about 4 resistors. No USB or serial port connection, no adjustments, no software drivers, and no PTT connection, either (it uses the transceiver's VOX). What am I missing by using such a simple interface vs. one that costs ~$100? Is something going over my head here? I see people with these commercial units complain about (among other things): My computer doesn't have a serial port, and so I can't use it. I'm having trouble installing the drivers supplied by the manufacturer of the interface. Why is this so complicated? ... and the list goes on. Why do we need to use a USB or serial port to get on PSK31 or other digital modes? Why do I need a separate sound card? What's wrong with using my computer's sound card? What is the driver software needed for? I have all three of my hearing aids at maximum. Please educate me.