I'm in the process of Echolink validating my call sign tonite, so I won't be able to do anything until (probably) tomorrow or later.

It isn't clear to me if a radio is even required? That is, it seems like a node could just have an internet-connected PC containing a sound card and a headset plugged into the sound card rcv/xmit. Is this right?

If a radio needs to be connected to a PC (through a TNC??) in order for Echolink to work, I guess I'll need to save up for a TNC (planning on this, anyway).