All three "Powers of 10" puzzles were just math and number systems. No big problem. The Quadrangle Challenge was both a challenge and a simple cipher. The challenge part was having to find at least one geocache in each topo map quad covering Lancaster County. Given how far away I live from Lancaster, I was surprised that I'd already qualified for this challenge. So it was a simple matter of going and finding the final cache.
"Ohm Overload" is probably more of interest to Electrical Engineering folks. (I'm Comp Sci. :) ) In this puzzle, coordinates are derived from the total resistance in two circuits. I knew the formulae from having had Physics class long ago, so all I really needed to do was look up resistor codes and do the math.
"Playfair 6" is a modified Playfair cipher. I decoded the message by hand since there is no software for this Playfair variant yet. However, as I found out, the real puzzle was finding the correct parking lot. It's in an area where none of the parking lots were connected, so I drove in and out a few times until I got the correct one. (I should've studied an aerial photo first.)
Watch Your Step (Pennsylvania)
Camo's First Cache (Pennsylvania)
Powers of 10 - Medium (Pennsylvania)
Powers of 10 - Easy (Pennsylvania)
Vogansville (Pennsylvania)
Powers of 10 - Hard (Pennsylvania)
Codebreaker (Pennsylvania)
Playfair 6 (Pennsylvania)
Christmas Gift 1 (Pennsylvania)
CR - Levidan Says What? (Pennsylvania)
Zone Improvement Plan (Pennsylvania)
You've gotta start somewhere! (Pennsylvania)
Ohm Overload (Pennsylvania)
Lancaster County Quadrangle Challenge (Pennsylvania)
Timberrrrrrr!!! (Pennsylvania)
Old Souls - Fraim 1857 (Pennsylvania)
Old Souls - Kurtz 1853 (Pennsylvania)
Old Souls - Mausoleum (Pennsylvania)
CR - What's all the buzz about? (Pennsylvania)
Wanna See My Skates?? (Pennsylvania)
Battleship - A6 (Pennsylvania)
cache me if you can (Delaware)
Woods Road Micro (Delaware)