What large antenna works best for a crystal radio?

[jbivy]

im using 365pf poly film air variable capacitors (instead of the 280's that the design called for), a 1n34 diode, a .001 cap, a 350uf coil (i had it so i used it). Instead of headphones (im a bit deaf) im using a tiny headphone amp that powers a 2" speaker. Im getting one station in wonderfull, with a bit of bleeding of another on it.

and of course i have both the ground wire and antenna hooked up. The results were pretty lousy. On a lark i connected the antenna to the ground as well and it got far better reception. The "ground" can be disconnected without much loss. Im just baffled at this point.

Im debating changing out the coil for a roller coil. I hope that adds some more selectivity. http://www.ebay.com/itm/251004411630...84.m1438.l2649