That would be balu
n of course- and is exactly the antenna I had recommended earlier.
It doesn't surprise me that the 394 overloaded somewhat - most portables simply can't handle long antennas - they're not built at all for that kind of higher input. A shorter antenna is likely to be the cure, though that seems to go against convention.
Now as to connecting a long wire to a receiver that only has a SO239 jack - you'll have to be more specific. For the 1500 or the 75? If it's for the 1500, then the suggestion above will work just fine (in point of fact, it'll work on both receivers just fine...)
The 75 has binding posts in the back for a single wire antenna - you then, if I'm not mistaken, need to make sure the receiver is taking its input from that post with a change in a setup menu. I don't have a R75, but that's what I seem to recall.
There are several possibilities on our Antennas wiki to get that noise down; the Par is a very good choice, building a loop (like the Carpet Loop, which isn't all that hard...) is another. Do some research and see which solution might work the best for you. The URL is:
http://wiki.radioreference.com/index.php/HF_Antennas
73s Mike