The aperture is fixed, so no adjusting it. The primary Aperture is 70mm and the Focal Length is 700mm, so it's basically f/10 without the teleconverter. If I have the concept right, the x2 telconverter doubles the focal length making it a fixed f/20.
It has been suggested to me to try increasing the ISO a bit and increasing the shutter speed. But it will be a few weeks before I have the opportunity to try again. I want to see if I can get the shot a little sharper and clearer. It's possible that what I lose due to a higher ISO will be more than made up for since I'm still getting a little motion blur.