Tikz: draw path starting at an anchor and just going a specific distance in some angle

I would like to draw a decoreted path starting at the anchor of one node and going in a specific direction for a specific distance.

I Found something like this:

\draw(node.north) -- (50:2cm);


This schould go a distance of 2cm starting at node.north and going in an angle of 50. However, this did node work in my case.

My code:

\draw[decorate,decoration={expanding waves, angle=65, segment length=8}] (stoer.north)  -- (<???>);


The aim is to go straight 3cm up. So starting at stoer.north and ending 3cm above stoer.north (however maybe other directions should also be possible)

How could this work? I also tried something like

(stoer.north) -- (stoer.north shift (0,3));


You can use relative coordinates with ++:

\documentclass[tikz,border=1.2345cm]{standalone}

\usetikzlibrary{decorations.pathreplacing}

\begin{document}

\begin{tikzpicture}
\node (thisnode) at (5,10) {A};% Random coordinates just to prove functionality
\draw (thisnode.north) -- ++ (90:3cm);
\draw (thisnode.north) -- ++ (50:2cm);
% One with the decorations
\node (stoer) at (5,5) {A};% Random coordinates just to prove functionality
\draw [decorate,decoration={expanding waves, angle=65, segment length=8}] (stoer.north) -- ++ (90:3cm);
\draw [decorate,decoration={expanding waves, angle=65, segment length=8}] (stoer.north) -- ++ (50:2cm);
\end{tikzpicture}

\end{document}