If I perform a cal with an 85052B kit and then connect the load from my 85033D it looks close (but not as as good as) the load from the 85052B to 26.5 GHz. I suspect how they perform above 6 GHz may be a little hit/miss. I don't think I'd want to count on it for a 26.5 GHz cal unless it was verified against a known good kit. I did test my 85033D(rated to 6 GHz) and it looks as good as my 85052B to 9 GHz when they are compared after performing a calibration using a 9 GHz e-cal unit. I'd love to do a full test to a higher frequency but cheap e-cal units don't come along very often.
Steve Draper