Greetings geeman:
I hope you like the E5. I have one too and I'm quite happy with it.

I'm located in northern California, and the antenna configuration that seems to work best for me most of the time is horizontal, pointing north-south. This is how I typically use the telescopic built-in antenna. There's also a wire antenna hanging from string on a light fixture and from the corner of my blinds, running horizontal along my ceiling. (It helps that I live on the top floor of the building.)

Antenna placement involves both increasing the signal and avoiding local interference. Sometimes the built-in antenna will be better than an external antenna. If you're finding that all of the shortwave signals are weak, think about trying an active loop antenna.