diff --git a/ch32v/ch32v203-goertzel/adcgoertzel.c b/ch32v/ch32v203-goertzel/adcgoertzel.c
index 811604e..09ecfa3 100644
--- a/ch32v/ch32v203-goertzel/adcgoertzel.c
+++ b/ch32v/ch32v203-goertzel/adcgoertzel.c
@@ -112,13 +112,21 @@ const int32_t g_goertzel_coefficient_s = 1984016189;
 
 #endif
 
+#if 0
+#define PWM_PERIOD (30-1)
+#define GOERTZEL_BUFFER (320)
+const int32_t g_goertzel_omega_per_sample = 990894956; // 0.146875 of whole per step / 101.505000MHz
+const int32_t g_goertzel_coefficient = 1296126516;
+const int32_t g_goertzel_coefficient_s = 1712233066;
+
+#endif
+
 #if 1
 #define PWM_PERIOD (30-1)
-#define GOERTZEL_BUFFER (396)
-const int32_t g_goertzel_omega_per_sample = 5485805733; // 0.813131 of whole per step / 90.303030MHz
-const int32_t g_goertzel_coefficient = 829669840;
-const int32_t g_goertzel_coefficient_s = -1980740764;
-
+#define GOERTZEL_BUFFER (384)
+const int32_t g_goertzel_omega_per_sample = 4251712402; // 0.630208 of whole per step / 27.025000MHz
+const int32_t g_goertzel_coefficient = -1468003291;
+const int32_t g_goertzel_coefficient_s = -1567371161;
 #endif
 
 int intensity_max = 1;
diff --git a/ch32v/lib/calculator.html b/ch32v/lib/calculator.html
index 9087ef7..327270a 100644
--- a/ch32v/lib/calculator.html
+++ b/ch32v/lib/calculator.html
@@ -80,7 +80,9 @@ function computeTable()
 			"<TR><TD>Goertzel</TD></TR>" +
 			"<TR><TD>Goertzel (Inverse)</TD></TR>" +
 			"</TABLE><TEXTAREA ROWS=6 COLS=120 ID=goertzeloutput></TEXTAREA>" +
-			"<P>Click on a ordinal offset to create the C code needed for that tuning parameter. Clicking will copy-to-clipboard.</P>";
+			"<P>Click on a ordinal offset to create the C code needed for that tuning parameter. Clicking will copy-to-clipboard.</P>" +
+			"<P>N Divisor #30 (row 3) is usually pretty good.  And, try to select things near 0.25 / 0.75, and avoid 0.0, 0.5, and 1.0.</P>" +
+			"<P>Goertzel's mode is for the ch32v203</P>";
 	}
 
 	contents += "<TABLE BORDER=1>";