I've seen many EDC/KH calibrator models but your VSS 330 is novel; most of EDC's popular calibrators were precision low voltage types; VS330 has such a wide dynamic range, 100nV to 300VDC, 30 ppm. The variants of the 100 were popular i.e., 103, 106, 106J etc., IIRC the manual for those models are almost identical except for the added functions that were linked to the key reference board. Additional specs: http://www.ebay.com/itm/EDC-VS330-/141017199834?pt=LH_DefaultDomain_0&hash=item20d547b4da EDC made a good number of products with variations and judging from KH selection, not all of the documentation was salvaged when KH bought EDC. At 09:08 PM 8/5/2013, Joseph Gray wrote: >I got another response from K-H. They also won't calibrate this model. > >So far, the only place that I have found a manual is Surplus Sales. They >list a "copy" of the manual for $20. I'll think about it while I keep >looking for a free one. > >Joe Gray >W5JG Sincerely, Marv Philadelphia, PA