I got a strange idea about the power supply issue on the Takahashi TG-SP II.
Since it's very small, and the tracking system is very energy efficient at 6V 130mA and so I wonder if it could be powered by the USB port. USB port can deliver 5V at 100mA norminal, and can be up to 5.25V at 500mA but it might require software handshake with the USB host controller in some case.
Electronic noise from the USB power supply is not an issue, according to a local friend, for it uses TTL logic which should accept up to 0.5V tolerance. But still, 5.25V looks a bit low.
During the discussion, it was mentioned that even a battery box with 4 pieces of AA battery (GP to be specific) can drive the mount continuously up to 20 hours, so maybe it's really worth to make sure a USB power cable?
However, since we can buy power supply box (powered by AA battery) with "USB port" interface, making such a cable might worth since in the worst case, we can fall back to use the power from our notebook.
The notebook computer will want a 12V SLA for over-night purpose, and if the TGSP-II requires a seperate 6V, it could mean extra burden, of course, if it's just 4AA batteries, it's okay.
USB power cable can be found in many places now, so the overhead is pretty small here.