> If you spend a lot of money on an interface, > it's because you wanted to, not because you need to.
Right ! The main points of such an interface are to provide isolation between PC and Rig. This is normally done by audio-transformers for the mic and speaker lines, optoisolators for ptt line. The main problem i have seen in commercial interfaces is a bad frequency response for the audio. 50hz to 3khz should be flat. With some interfaces, it's not. The other problem are the cat-ptt devices. There is no point in having the audio isolated but running a ground-loop trough the cat-interface. I think the simple optoisolated "single rts ptt" devices are superior. If you have to use CAT for PTT you need a fully isolated CAT port ! The "ideal" solution would be to run the whole audio and ptt trough optical cables. Most soundcards do support optical, but i have never seen the Rig-counterpart for this. If you are a builder, it's a hand full of parts. If you > have any old PC modem cards, you can steal the audio isolation transformers > off of them and get past two important parts for free. > > Or buy something like the Rascal kit and build it. Comes with interface cables > and everything shipped for under $50. > > It's not like it's some complicated piece of equipment. >
