diff --git a/freedata_gui/src/components/settings_modem.vue b/freedata_gui/src/components/settings_modem.vue
index 9b61cfbb..ac0d6edc 100644
--- a/freedata_gui/src/components/settings_modem.vue
+++ b/freedata_gui/src/components/settings_modem.vue
@@ -173,7 +173,7 @@ const audioStore = useAudioStore();
       v-model.number="settings.remote.MODEM.maximum_bandwidth"
     >
       <option value="250">250 Hz</option>
-      <option value="563">563 Hz</option>
+      <option value="500">500 Hz</option>
       <option value="1700">1700 Hz</option>
       <option value="2438">2438 Hz</option>
     </select>
diff --git a/freedata_server/codec2.py b/freedata_server/codec2.py
index 63448897..20a9c11f 100644
--- a/freedata_server/codec2.py
+++ b/freedata_server/codec2.py
@@ -542,11 +542,11 @@ data_ofdm_500_config.config.contents.ts = 0.016
 data_ofdm_500_config.config.contents.rs = 1.0 / data_ofdm_500_config.config.contents.ts
 data_ofdm_500_config.config.contents.nc = 8
 data_ofdm_500_config.config.contents.timing_mx_thresh = 0.10
-data_ofdm_500_config.config.contents.bad_uw_errors = 8
+data_ofdm_500_config.config.contents.bad_uw_errors = 18
 data_ofdm_500_config.config.contents.codename = "H_1024_2048_4f".encode('utf-8')
 data_ofdm_500_config.config.contents.amp_scale = 305E3
-data_ofdm_500_config.config.contents.nuwbits = 32
-data_ofdm_500_config.config.contents.tx_uw = create_tx_uw(32, [0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1])
+data_ofdm_500_config.config.contents.nuwbits = 54
+data_ofdm_500_config.config.contents.tx_uw = create_tx_uw(54, [0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1])
 data_ofdm_500_config.config.contents.clip_gain1 = 2.4
 data_ofdm_500_config.config.contents.clip_gain2 = 0.9
 data_ofdm_500_config.config.contents.tx_bpf_en = True