diff --git a/tools/ld-chroma-decoder/encoder/main.cpp b/tools/ld-chroma-decoder/encoder/main.cpp
index 926614844..a0ff6cad6 100644
--- a/tools/ld-chroma-decoder/encoder/main.cpp
+++ b/tools/ld-chroma-decoder/encoder/main.cpp
@@ -77,7 +77,7 @@ int main(int argc, char *argv[])
 
     // Option to select chroma mode (--chroma-mode)
     QCommandLineOption chromaOption(QStringList() << "chroma-mode",
-                                     QCoreApplication::translate("main", "NTSC only. Chroma encoder mode to use (wideband-yuv, wideband-yiq; default: wideband-yuv)"),
+                                     QCoreApplication::translate("main", "NTSC only. Chroma encoder mode to use (wideband-yuv, wideband-yiq, narrowband-q; default: wideband-yuv)"),
                                      QCoreApplication::translate("main", "chroma-mode"));
     parser.addOption(chromaOption);
 
@@ -142,6 +142,8 @@ int main(int argc, char *argv[])
         chromaName = parser.value(chromaOption);
         if (chromaName == "wideband-yiq") {
             chromaMode = WIDEBAND_YIQ;
+        } else if (chromaName == "narrowband-q") {
+            chromaMode = NARROWBAND_Q;
         } else if (chromaName == "wideband-yuv") {
             chromaMode = WIDEBAND_YUV;
         } else {
diff --git a/tools/ld-chroma-decoder/encoder/ntscencoder.cpp b/tools/ld-chroma-decoder/encoder/ntscencoder.cpp
index a6c1f6437..6dfa9cd64 100644
--- a/tools/ld-chroma-decoder/encoder/ntscencoder.cpp
+++ b/tools/ld-chroma-decoder/encoder/ntscencoder.cpp
@@ -268,18 +268,26 @@ static double syncPulseGate(double t, double startTime, SyncPulseType type)
     return raisedCosineGate(t, startTime, startTime + length, 200.0e-9 / 2.0);
 }
 
-// 1.3 MHz low-pass Gaussian filter, as used in pyctools-pal's coder.
-// Generated by: c = scipy.signal.gaussian(13, 1.49); c / sum(c)
+// 1.3 MHz low-pass filter
 //
-// The UV filter should be 0 dB at 0 Hz, >= -3 dB at 1.3 MHz, <= -20 dB at
-// 4.0 MHz. [Clarke p8]
-static constexpr std::array<double, 13> uvFilterCoeffs {
-    8.06454142158873e-05, 0.0009604748783110286, 0.007290763490157312, 0.035272860169480155, 0.10876496139131472,
-    0.21375585039760908, 0.2677488885178237, 0.21375585039760908, 0.10876496139131472, 0.035272860169480155,
-    0.007290763490157312, 0.0009604748783110286, 8.06454142158873e-05
+// The filter should be 0 dB at 0 Hz, >= -2 dB at 1.3 MHz, < -20 dB at
+// 3.6 MHz. [Clarke p15]
+static constexpr std::array<double, 9> uvFilterCoeffs {
+    0.0021, 0.0191, 0.0903, 0.2308, 0.3153,
+    0.2308, 0.0903, 0.0191, 0.0021
 };
 static constexpr auto uvFilter = makeFIRFilter(uvFilterCoeffs);
 
+// 0.6 MHz low-pass filter
+//
+// The filter should be 0 dB at 0 Hz, >= -2 dB at 0.4 MHz, >= -6 dB at
+// 0.5 MHz, <= -6 dB at 0.6 MHz. [Clarke p15]
+static constexpr std::array<double, 23> qFilterCoeffs {
+    0.0002, 0.0027, 0.0085, 0.0171, 0.0278, 0.0398, 0.0522, 0.0639, 0.0742, 0.0821, 0.0872, 0.0889,
+    0.0872, 0.0821, 0.0742, 0.0639, 0.0522, 0.0398, 0.0278, 0.0171, 0.0085, 0.0027, 0.0002
+};
+static constexpr auto qFilter = makeFIRFilter(qFilterCoeffs);
+
 void NTSCEncoder::encodeLine(qint32 fieldNo, qint32 frameLine, const quint16 *rgbData, QVector<quint16> &outputLine)
 {
     // Resize the output line and fill with blanking
@@ -394,7 +402,11 @@ void NTSCEncoder::encodeLine(qint32 fieldNo, qint32 frameLine, const quint16 *rg
 
         // Low-pass filter chroma components to 1.3 MHz [Poynton p342]
         uvFilter.apply(C1);
-        uvFilter.apply(C2);
+        if (chromaMode == NARROWBAND_Q) {
+            qFilter.apply(C2);
+        } else {
+            uvFilter.apply(C2);
+        }
     }
 
     for (qint32 x = 0; x < outputLine.size(); x++) {
diff --git a/tools/ld-chroma-decoder/encoder/ntscencoder.h b/tools/ld-chroma-decoder/encoder/ntscencoder.h
index bf38c1327..c55ecd834 100644
--- a/tools/ld-chroma-decoder/encoder/ntscencoder.h
+++ b/tools/ld-chroma-decoder/encoder/ntscencoder.h
@@ -35,6 +35,7 @@
 enum ChromaMode {
     WIDEBAND_YUV = 0,   // Y'UV
     WIDEBAND_YIQ,       // Y'IQ
+    NARROWBAND_Q        // Y'IQ with Q low-passed
 };
 
 class NTSCEncoder