How Long Do Presets Stay In Battery Radios

Factual Questions
1

I have two radios one is a Sony walkman and as soon as I remove the batteries to replace them all the presets for the AM / FM tuners go back to the factory defaults.

The other day I was cleaning a closet and I came across an old Panasonic walkman that had radio on it and I put batteries in it to see if it still worked. To my surprise ALL the preset stations were still there. Nothing reset and I that Panasonic walkman hadn’t had batteries in it for at least three years?

Why the difference?

2

One manufacturer chose to store the presets in some form of nonvolatile memory, which does not need a constant supply of power to retain its contents, the other chose volatile memory, which does. Why? Probably cost.

3

I was staring at the thread title trying desperately to try and figure out what it was saying. I’ve already fallen behind in techno pop culture. I can’t affiord to lose more ground.

OK – a couple of errors in the title. I can deal with that.