[Lowfer] Imperial versus metric measure (was MHz and mHz)

[Ed Phillips]

John Davis wrote:
> 
> Alberto is quite right about distinguishing between mHz and MHz, by a factor
> of a billion to one!

	Of course Alberto is right - he knows what he is doing.
 
> Well, "American billion" at least.  That's another of those tricky
> designations whose ambiguity can best be eliminated by using universally
> accepted prefixes.  Giga, mega, kilo, milli and the rest are all worth
> careful use.  Likewise, the distinction between kb and kB in the computing
> world.
> 
> But I think much of the consternation over units on this side of the pond
> arises because of sometimes having to re-learn names of familiar units.  I
> appreciate the desirability of honoring pioneers in the science and
> technology of our field, but I have to confess to some trouble myself
> accepting Siemens in place of the good old intuitively recognizable mho as
> the unit of conductivity.

	I personally can handle the new names, although in same cases I think
they are foolish and contrived.  After all, in the beginning we had to
learn the names we are familiar with.  My problem with the adoption of
the metric system HERE is when it actually changes the size of things! 
Metric fasteners come to mind, and of course the volume measures used in
commerce, with attendant ripoffs due to customer ignorance.   

> What's worse, though, is how some such changes tend to cascade, forcing us
> into whole new areas of technology.  That's what's uncomfortable for many
> people.  As an example of what I mean, think back to the good old days when
> a kilocycle was a kilocycle, and radios were glad of it!
> 
> But then, fashions changed, and we had to use those trendy new kilohertzes.
> Well, look at all the changes that caused!  Suddenly, the Heaviside layer no
> longer worked for long range communication.  We had to switch to bouncing
> our signals off the ionosphere instead.  And because the ionosphere doesn't
> respond as well to signals from Marconi or Hertzian aerials, we had to
> switch to using monopole and dipole antennas.  And while those older aerials
> were comfortable working with valves and tubes, according to one's personal
> preferences, we were inevitably forced to invent transistors to gain maximum
> benefit from the new-fangled antennas.
> 
> I'll tell you, it just seems to be a never-ending cycle.  Or is that a
> never-ending Hertz?

	I always prefered CPS for the pioneering electrical engineer, Charles
Proteus Steinmetz.
 
> 73,
> John

Ed

	Who, to answer Alberto's question about wavelength, at times uses
microns, millimeters, centimeters, meters, inches, feet, and both
kilometers and nautical miles;  all depends on the subject matter.  I do
a lot of radar performance calculations in which things like range,
antenna diameter, target radar cross section, and wavelength show up. 
Sometimes one unit is more convenient than another.

	By the way, I don't think any self-consistent and unambiguous system of
units is wrong.