Every Maker Should Have [Pt.40]...an HP-15C, HP-35S or a Casio fx-61F

3 scientific calculators for electronics buffs. Support Roger on Patreon: https://www.patreon.com/kainkalabs Each one with unique features not found anywhere else: HP-15C: http://www.hpmuseum.org/hp15.htm HP "Voyager" Series with HP10C, HP11C etc.: https://en.wikipedia.org/wiki/Hewlett-Packard_Voyager_series HP-35S: https://en.wikipedia.org/wiki/HP_35s Manual: http://h10032.www1.hp.com/ctg/Manual/c01579350 CASIO fx-61F: http://www.usersmanualguide.com/casio/calculators/fx-61f Other recommended CASIO calculators for engineers: CASIO fx-115D CASIO fx-570 AD Radio Shack EC-4032 (rebranded CASIO fx-570AD with solar cells) Support Roger on PATREON: https://www.patreon.com/kainkalabs