Shack Cleaning........... Number above the Collins logo: TFISX03YY Underneath the logo: No.672 0530 009 Power Transformer 50/60 CPS Then the schematic showing two 115 vac primaries Secondary with a common and four taps Then: Output Term. 5-9 830 VRMS +/- 4% .36A 6-8 286 VRMS +/- 4% .12A MAX ALT 10,000 FT. Any interest in this item? Thanks, John