I am intrigued with the idea of a totally passive reciever -one that
requires no power source- and so find myself looking into building a
crystal set for myself. I found what appears to be a pretty easy
build-up at this page: http://antiqueradio.org/econmain.htm

To my non-expert eye, it appears to be a very well thought out, clever
design.

My questions a

1. Is it possible to modify the design to also allow for the clear
reception of ssb signals while maintaining the "passive" characteristic
that I find so appealing?
2. Would it be difficult to modify the design to allow reception above
the stated ~17Mhz upper limit to, say, 30Mhz?

Any input/thoughts will be much appreciated.