There is a small section near the end of the qsyer manual which contains a 
mod to power it from the ci-v port on icom radios.
It involves placing a capacitor across the ci-v port.
This is supposed to work for the 703, 706, etc.  Not sure about the 7000.
It also says that this will work, but allow time between uses for the cap to 
charge.
If you need it, I'll try and dig up the text and send it along.