What kind of "CW"? Keyed carrier or modulate tone (MCW)?

well i would preffer amplitude modulated tone....

The simplest receiver you could build would be a superregenerative,
as was used in simple handhelds sold in the early 1950s. That would
work fine for MCW type signals, but would not do for keyed carrier
CW.

wheare i can found schematics of that handhelds?