Argosy II (525) POP
I just procured an Argosy-II a couple of weeks ago and tried using it on CW. The full QSK that is so nice on the Argonaut, Corsair and Omnis, has an annoying "pop" on the Argosy.
After looking through some ARRL Hints and Kinks, I found a mod that replaces the stock 1 mfd cap at C-40 on the IF board with a 10 mfd 16 volt electrolytic. This slows down the AGC recovery and reduces or eliminates the "popping" encountered when using CW on the Argosy.
I performed that mod this evening (took about 15 mintues) and boy, what a difference! My Argosy-II is now fun to use on CW.
73 rich K7SZ