A mid-afternoon power outage one Sunday helped me with a question to which I had been searching for an answer for quite some time: what should I use as my "reference" radio for AM?
For FM, the answer was obvious, but I'll get to that in another post. But for AM, I have had some dissatisfaction or another with just about every one I have. My vintage Zeniths sound great, are reasonably sensitive, and seem especially resistant to electrical interference. But they are not all that selective. Possibly reflecting its other line of business, hearing aids, Zenith emphasized sound quality over selectivity. Even though its portable radios usually started rolling off their frequency response at 4 kHz, the rolloff isn't particularly sharp, providing a pleasant, mellow sound in many circumstances.
Newer digital radios have their own issues. Often they suffer from self-generated noises. This is true of the DSP-based Tecsun and Degen radios. Sangeans seem to do better, and are definitely selective, but that selectivity comes at the cost of audio quality.
Using the GE Superadio that I had just acquired led me to find a pretty good answer to my question. There is some sacrifice of audio quality, but not obnoxiously so, and the radio is still selective. Picking up KKOH Reno at 2 pm on a summer afternoon, right next to KCBC at 770 and the very, very strong local signal of KGO was indicative of both excellent sensitivity and selectivity.
Why not the Superadio II? It's probably a good candidate, too. I didn't happen to have it on at the time. I do like the Superadio's audio on AM a little better. It seems a bit less noisy, possibly because a separate tweeter isn't used.
(Aside: There is no such thing as a "Superadio I" just as there's no such thing as a "first annual" event.)
There are lots of websites with many more details about the GE Superadio series, so I'll just point you to them and say that my experiences with the first model and with the Superadio II are consistent with what many of those sites say. It shouldn't have come as a surprise, then, that I found it to be the radio that I can describe as excellent for AM reception.