Spangehl Not Spanghel

I suspect "Spanghel" is just a misspelling of "Spangehl," which is the way my family has always spelled it. German names with a vowel + H to indicate the vowel is pronounced long are common: Fehr, Gehl (a tractor company in Wisconsin), etc. All my life people have had trouble spelling and pronouncing my name, except when I've visited Germany and Switzerland.