Ovation Guitar #70 Internal Test/Specification Record - Model 1687-7, S/N 0070

This is an internal Ovation guitar engineering document (not a catalog or brochure) consisting of a specification/measurement record sheet and an acoustic frequency response graph for guitar #70, Model 1687-7, Serial Number 0070. The specification sheet dated 12/14/76 details construction parameters including top type, bridge dimensions, brace weights, and deflection measurements (RL, SN, K), with a follow-up entry dated 6/8/77 noting it was used as a show guitar on pedestal and not sound tested. The accompanying frequency response chart, dated 7-11-77 and signed by technician D. Johnson, shows the acoustic output in dB across the full frequency spectrum from approximately 30 Hz to 8372 Hz, with notable resonance peaks annotated at frequencies such as 94, 177, 477, 556, and 816 Hz.