For years I have thought about buying one of the older Argonauts, either the 509 or 515 models. I have never used one. I would appreciate some pointers about the strengths and weaknesses of these radios for CW and SSB use. I can probably adapt my Autek audio filter to one of these to sharpen it up for cw, and add a notch. Any comments? tnx, Steve WA9JML