diff --git a/4410-4412.tex b/4410-4412.tex
index bd9f990..e9f4c1a 100644
--- a/4410-4412.tex
+++ b/4410-4412.tex
@@ -476,7 +476,7 @@ Note that the phase difference between the 2 channels might not be exactly 0.25
 It can be negated by adjusting the \texttt{phase} parameter.
 
 \newpage
-\subsection{DDS RAM Modulation (AD9910 Only)}
+\subsection{Periodic RF pulse (AD9910 Only)}
 This examples demonstrates that the RF signal can be modulated by amplitude using the RAM modulation feature of AD9910.
 By default, RAM profiles are programmed to profile 0.
 
@@ -533,6 +533,38 @@ The generated RF output of the above example consists of the following features
     \item Go back to item 1.
 \end{enumerate}
 The expected waveform is plotted on the following figure.
+Note that phase of the RF pulses may drift gradually.
+Urukul was operated with a 50$\Omega$ termination to produce the waveform.
+
+\begin{tikzpicture}[
+    declare function={
+        func(\x)= (\x<0) * (0) +
+            and(\x>=0, \x<2) * (0.42*cos(deg(10*pi*\x))) +
+            and(\x>=2, \x<3) * (0) +
+            and(\x>=3, \x<4) * (0.42*cos(deg(10*pi*\x)))) +
+            and(\x>=4, \x<7) * (0) +
+            and(\x>=7, \x<7.5) * (0.42*cos(deg(10*pi*\x)));
+    }
+]
+\begin{axis}[
+    axis x line=middle, axis y line=middle,
+        every axis x label/.style={
+            at={(ticklabel* cs:1.05)},
+            anchor=west,
+        },
+        every axis y label/.style={
+            at={(ticklabel* cs:1.05)},
+            anchor=south,
+        },
+    height=5cm,
+    width=16cm,
+    ymin=-0.5, ymax=0.5, ytick={-0.42,0.42}, ylabel=Voltage ($V$),
+    xmin=-0.5, xmax=7.5, xtick={0,...,7}, xlabel=Time ($\mu s$),
+]
+
+\addplot[blue, samples=1000, domain=-0.5:7.5]{func(x)};
+\end{axis}
+\end{tikzpicture}
 
 \begin{figure}[h]
     \centering
diff --git a/ad9910_amp_mod.png b/ad9910_amp_mod.png
deleted file mode 100644
index e0e6259..0000000
Binary files a/ad9910_amp_mod.png and /dev/null differ