I know. At least, the whip antenna on the portable has the added advantage of being in the middle of the room, away from any electrical wiring in the walls or the metal mesh that holds the stucco on the building's exterior.I wish you could get more than 23' of wire outside. 23' is just a hank of wire. A longer wire would give that poor R75 a better chance at "being all it can be". But I understand your situation there.
One thing about the Sangean: Signal strength (as well as noise level) is noticeably lower on batteries than on the AC adapter, which is how I usually run it. The adapter outputs 9v. AC, and emits no noise of its own. The supply voltage is regulated inside the radio, so the voltage is probably pretty much the same as with batteries. I suspect that there may be either an antenna or ground effect through the power cord.
This morning BSKSA was coming in strong again, so I tried running the radio on fresh alkaline batteries. There was a significant drop in signal according to the meter, but I still got a decent signal. As I gradually brought the power cord closer to the jack before plugging it back in, the strength started increasing while the radio was still running on the batteries. Some capacitive coupling must be going on there, which seems to confirm what I had suspected about the power cord.