I have a Zenith C845 and like it, a lot. They don't make them like that anymore. Mine will bring in stations from 100 miles away on AM in the daytime, further away at night, and the FM is quite sensitive as well. I live in a small town 33 miles east of downtown Cleveland, but my C845 receives every station in the city just as well as if I were just five miles from the transmitters (the transmitters and towers for most Cleveland AM and FM stations are over 30 miles southwest of here). Zenith really had a winner in the 800 series of table radios from the '50s-'60s;
it's a darn shame today's radios can't hope to perform at least as well, as today's one-chip portables are doing well if they can receive stations 15 miles away.
I guess, however, with so many local stations on the air today, radios don't have to be as sensitive as the old Zenith and other sets needed to be 50+ years ago. As was stated by another AKer in this thread, the reason the old radios from the '30s until perhaps the seventies were built for DX (distance reception) was because they had to be -- not every town had a local station in those days. Today, that sensitivity can be put to good use to find music stations on AM, as most AM stations these days program non-music formats. My C845 gets AM stations from 70-80 miles away that play older music (not rock), and FMs from at least that far away when the band is open.
I am also impressed by the C845's ability to handle very strong signals without overloading. There is a 1kW AM station about two miles from me that can be heard at two points (its fundamental frequency of 1460 kHz and 0.9 MHz down the dial) on the AM radio tuner in my stereo system, but on the C845 and every other Zenith radio I own, I hear that station on 1460 and
only 1460. A new FM station in the same area went on the air last year; like the AM station, the new FM is only perhaps two miles from my apartment but it comes in only on its fundamental frequency, 88.3 MHz, on every one of my FM radios, including my 11-year-old Aiwa stereo, without overloading. However, the 845 handles this station very well, no overloading or spurious responses across the dial, something I attribute to the excellent signal circuitry this radio has.
This type of circuit design, unfortunately, will never again be seen in today's radios; the AM sections of today's portables are made about as cheaply as the manufacturer can get away with--and have been for decades. A prime example of this is the AM tuner section of a Zenith stereo system I owned in the '80s. That system's AM tuner has to be one of the worst I have ever seen in a compact stereo; it worked well enough in the daytime, but at night I could hear shortwave stations between roughly 1120 and 1160 kHz. I often describe the AM tuner in this stereo as not being much better than a crystal set, and that's being kind. The thing that baffled me about that system, however, is that the FM tuner was very sensitive, bringing in every local FM station in Cleveland noiselessly with just a line-cord antenna (I lived in a Cleveland suburb at the time that was perhaps 25 miles from the stations' towers). Why was the FM section of this unit so much better than the AM tuner? The only thing I can figure is that, since most AM stations today are talk or other non-music formats and many AMs are going off the air permanently, the manufacturers of today's stereo systems and portable radios very likely don't see the sense in going to the trouble (to say nothing of the expense) of designing the AM tuners for wide bandwidth and/or high RF sensitivity, so they channel that expense and R&D work into the FM circuitry. The result? AM tuners as bad (or worse) than that in my Zenith integrated stereo.
One of the best AM/FM transistor portables I have seen to date is my Zenith R-70 from 1980. Though built in Korea to Zenith's specifications, this radio could very well outperform any 21st century one-chip portable many times over, IMHO. The R-70 has four IF stages on FM, two IFs on AM and ceramic filters on both bands, push-pull audio output -- and its performance is excellent, better than most portables of that era. (The only thing I wish Zenith had designed into this set is an AFC defeat switch, to aid in tuning in stations close together on the FM dial.) Today's one-chip wonders cannot hope to perform nearly as well, since they are built so cheaply -- again, with just enough sensitivity to receive an area's local stations, and some of them don't do that very well.