Have you tried tinning Radio Shack's 274-284 connector? It acts as if it's made
of stainless steel. Maybe a chisel tip would work better.
Doug,
I too have found that RatShack audio connectors do not take to solder
well. Not always, perhaps a quarter to a third of the ones I've used.
A narrow chisel tip has worked well for me as has going to one of the
diminishing number of electronics supply shops for my parts. However,
I realize not every area has such a place. If you have a Fry's
Electronics store in your area it is worth looking there for both
audio and RF connectors as well as soldering equipment - pick out a
few different tips