I'm looking at a Z-12 for an opus unit to use with my promarks, but does not come with antenna. What antennas are compatible with the Z-12 units?
Not seeing any other replies, I will say that in one if my former jobs we used the Z-12 with the ASH701008.01B antenna.
Obviously there are other compatible with it, including choke ring versions. Some additional details may be found at the UNAVCO site. I found this: http://facility.unavco.org/kb/questions/475/Ashtech+Micro-Z+and+Z-12+Resource+Page
There is somewhere on the site information about power input and output; cannot seem to find it now.
Some additional specifications are on the NGS antenna calibration site at: 
HTH,
DMM
ASH701008.01 Rev-B
Ashtech Geodetic Antenna IIIa
sn 12002002
I have said Antenna sitting in my closet, and I might have a cable for it around here somewhere. It worked last time I used it (probably 10 years ago). If anybody wants it, I'll look for the cable, and send it off.
BTW it has a OEM "2 inch ID Pipe Mount Bracket" that is removable as well.
Loyal