Foundations Of Amateur Radio

Foundations of Amateur Radio In our hobby we use kilohertz and megahertz enthusiastically. Sometimes even gigahertz. The other day during a discussion the question arose, what comes after tera, as in terahertz? I couldn't remember, so I had to look it up, peta comes next, then exa, zetta and yotta, derived from the Greek word for eight. That in and of itself was interesting, but it turns out that Greek isn't the only language used in attributing SI metric prefixes, SI being the International System of Units. Of the 20 units, which I'll get to in a moment, there's 12 with Greek origins, five deriving from Latin, two from Danish and one from Spanish. The units are used to describe how many of a thing there are in base-10, so, a thousand of something is kilo, or ten to the power of three, which gives us kilohertz. A gigahertz is ten to the power of nine and so-on. Interestingly, kilo is derived from the Greek word thousand, but mega comes from the Greek for great. Both hecto, as in hectopascals and deca as in