Until the development of DSP radios such as the Tecsun PL-606 or the Degen DE1123, I was looking for a good, sensitive small-sized FM radio that was free of front-end overload. My Sony Walkmans are terrible in this regard. A friend who is the chief engineer of a regional chain of radio stations in the Midwest recommended the Panasonic RF-502.
It is indeed sensitive, and free of overload. It's sensitive despite having a relatively short antenna, just 34 centimeters (about 13 1/2") in length, which is too short for FM by more than half. The antenna also doesn't swivel, but since the radio is small (5" high by 3" wide by 1" deep), it's still reasonably maneuverable.
I tested out this radio in that most difficult of environments, my San Francisco office. It did reasonably well, though not as well as a Tecsun DSP radio has done.
One advantage in that environment -- it's a mono radio. That's a surprise for something manufactured from 1986 to 1988 (according to radiomuseum.org). With its basic controls and slide-rule dial, it looks like a throwback to the 1970s in some ways.
AM reception is good though selectivity is modest. At night, KNX (1070, Los Angeles), often a strong signal here, can be buried between the splatter from strong locals at 1050 and 1100. The audio bandwidth starts rolling off at 4 kHz, a fairly mainstream value, but obviously the rolloff is gentle. That means reasonably decent sound, at the expense of selectivity.
The radio's speaker is small, so you're not going to get big sound. The radio can play loudly, though. Audio quality with headphones is excellent.
Here's another way this radio is a throwback. There's a mono 3.5mm headphone jack. By the late 1980s, I would have expected that jack to have been a stereo jack wired for mono. A useful companion for this radio is a stereo-to-mono adapter. Radio Shack still sells those adapters, so no problem there.
While mono-only reception is a bit of a bummer for me, it's still a good radio and performs startlingly well. For some reason, I used to have something of a bias against Panasonic radios but I have come to appreciate the quality of many Panasonic designs, especially for FM reception. The RF-502 is a nice, compact example of that quality.