Deepermind Metric Units

Updated October 28, 2023
My business is fixing computers.  Call 972 978-9703
Deepermind Home Page

Computers are built around binary numbers.  Binary numbers 1, 2, 4, and 8 are written as 1, 10, 100 and 1000.  In binary there are just two symbols used 0 and 1. Every time you add another digit to the left of a binary number, you double the number.

We commonly use decimal notation which means very time you add another digit to the left of a binary number you multiply it by ten.

When a computer is built, it is built around binary numbers.  The number 1024 when written in binary is 1000000000.  You can see that binary numbers are awkward to write. Since 1024 is about 1000, the people started to call 1024 a "K". It is pretty close.  This is how much a kilobyte really is.

The next symbol was "M" and this was 1024 times 1024 which as pretty close to a million.  It actually is 1,049,576.  This is how much a megabyte really is.

As things got bigger, a "G" symbol was added.  This was 1024 times 1024 times 1024 or about a billion. But not exactly.  It really was 1,073,741,824. This is actually how much a gigabyte is.

Once again things grew in size.  A "T" symbol was added and this was 1024 raised to 4th power. The actual value was 1,099,511,627,776.  This is actually how much a terabyte is. You get 99.5 million bytes free.  That is nice.

To fix all this, in 1998, the International Electrotechnical Commission came up with their own prefixes.  The trouble was nobody paid attention. In theory it was a good idea.  Making Ki mean 1024, and K mean 1000 made sense.  But everyone liked K meaning 1024 in the computer world and 1000 for weights and measures. Just for fun here is a table of their "Standard Computer Prefixes" which never became standard.

International Electrotechnical Commission Computer Prefixes

Electromagnetic Spectrum

Capacitor Conversion Values

Thus 2¹⁰10^(-9) f = 1 nf = .001 uf = 1000 pf.

WAVELENGHT and FREQUENCY CONVERSION

c = f * w

w = c/f

f= c/w

where: w = wavelength in meters, f = frequency in Hz

             c =velocity of light in a vacuum = 299,792,458 m/s

_____________________

For f in MHz

 f = 300/w  approximation

w = 300/f  approximation

_____________________

Dipole length Antenna Formulas (f is in MHz)

Antenna length in meters = 150/f

Antenna length in inches = 5905/f

Antenna length in feet = 492/f

In actual practice, the end effect should be considered.  The result from the above formula should be multiplied by about 0.95.

Antenna length in meters = 142.5/f

Antenna length in inches = 5609.75/f

Antenna length in feet = 467.4/f

If a quarter length antenna is being considered with an end effect included:

Antenna length in meters = 71.25/f

Antenna length in inches = 2,804.875/f

Antenna length in feet = 233.7/f

Radio Bands (VLF, LF, MF, HF, VHF, UHF, SHF, EHF) Allocations

George Norwood
KE5KDO
Contact george@deepermind.com
972 978-9703 

Back to Deepermind Main Page