\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
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\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{avryhof (avryhof)}
\pdfinfo{
  /Title (ham-radio-technician-s-exam-cheat-sheet.pdf)
  /Creator (Cheatography)
  /Author (avryhof (avryhof))
  /Subject (Ham Radio Technician's Exam Cheat Sheet)
}

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% This two commands together give roughly
% the right line height in the tables
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\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
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\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
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\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Ham Radio Technician's Exam Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{avryhof (avryhof)} via \textcolor{DarkBackground}{\uline{cheatography.com/2677/cs/13419/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}avryhof (avryhof) \\
  \uline{cheatography.com/avryhof} \\
        \uline{\seqsplit{www}.vryhofresearch.com}
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 6th November, 2017.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{3}

\begin{tabularx}{5.377cm}{p{0.4977 cm} x{4.4793 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Variables}}  \tn
% Row 0
\SetRowColor{LightBackground}
E & Voltage in Volts \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
I & Current in Amperes (A) \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
R & Resistance in Ohms (Ω) \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
P & Power in Watts (W) \tn 
% Row Count 4 (+ 1)
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\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.59724 cm} x{4.37976 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Formulas}}  \tn
% Row 0
\SetRowColor{LightBackground}
300 = & Frequency (MHz) x Wavelength (Meters) \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
E & `I x R` (Ohm's Law) \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
P & `E x I` \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
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\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.62655 cm} p{0.4177 cm} x{1.92142 cm} x{1.21133 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{4}{x{5.377cm}}{\bf\textcolor{white}{Prefixes}}  \tn
% Row 0
\SetRowColor{LightBackground}
giga & G & 1,000,000,000 & GHz \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
mega & M & 1,000,000 & MHz \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
kilo & k & 1,000 & KHz \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
 &  & 1 & Hz \tn 
% Row Count 4 (+ 1)
% Row 4
\SetRowColor{LightBackground}
milli & m & 0.001 & thousandth \tn 
% Row Count 5 (+ 1)
% Row 5
\SetRowColor{white}
micro & μ & 0.000 001 & millionth \tn 
% Row Count 6 (+ 1)
% Row 6
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nano & n & 0.000 000 001 & billionth \tn 
% Row Count 7 (+ 1)
% Row 7
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pico & p & 0.000 000 000 001 &  \tn 
% Row Count 8 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}----}
\SetRowColor{LightBackground}
\mymulticolumn{4}{x{5.377cm}}{Sometimes these are written as exponents in scientific notation. \newline For values \textgreater{} 1: 10\textasciicircum{}(number of places)  \newline - ex: `Kilo: 10\textasciicircum{}3 = 1,000` \newline For Values \textless{} 1: 10\textasciicircum{}(-number of places){[}negative{]} \newline - ex: `milli: 10\textasciicircum{}-3 = 0.001`}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}----}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}