Editing VHF omnidirectional range (section)

===CVOR===
[[Image:vor conventional.gif|frame|alt=F3 (colour background) changes the same in all directions; A3 (greyscale foreground) pattern rotates N->E->S->W-> |Conventional VOR<br />red(F3-) green(F3) blue(F3+)<br />black(A3-) grey(A3) white(A3+)]]
The conventional signal encodes the station identifier, {{math|''i''(''t'')}}, optional voice {{math|''a''(''t'')}}, navigation reference signal in {{math|''c''(''t'')}}, and the isotropic (i.e. omnidirectional) component. The reference signal is encoded on an F3 subcarrier (colour). The navigation variable signal is encoded by mechanically or electrically rotating a directional, {{math|''g''(''A'',''t'')}}, antenna to produce A3 modulation (grey-scale). Receivers (paired colour and grey-scale trace) in different directions from the station paint a different alignment of F3 and A3 demodulated signal.

<math display="block">
\begin{array}{rcl}
e(A,t) & = & \cos( 2 \pi F_c t ) ( 1 + c(t) + g(A,t) ) \\
 c(t) & = & M_i \cos ( 2 \pi F_i t ) ~ i(t) \\
 & + & M_a ~ a(t) \\
 & + & M_d \cos ( 2 \pi \int_0^t ( F_s + F_d \cos ( 2 \pi F_n t ) ) dt ) \\
g(A,t) & = & M_n \cos ( 2 \pi F_n t - A ) \\
\end{array}
</math>