A full size 40m dipole built from wire would be pretty good bang for the buck. 66 ft long, and up as high as you can get it. Again, you do realize that this is a Morse code radio, right? No voice. It's also a "QRP" radio... a low power transmitter generally used by those of us who like the challenge of trying to get through with as little power as possible, just because it's tough! If you're really trying to get through to Germany, this is just about the hardest possible way to do it. You might accomplish it once or twice in a year, maybe.