diff --git a/search_app.py b/search_app.py
index da2d97e..1116dfc 100644
--- a/search_app.py
+++ b/search_app.py
@@ -746,6 +746,8 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
 
     @app.route("/api/channels")
     def channels():
+        include_external = request.args.get("external", default="0", type=str)
+        include_external = include_external.lower() not in {"0", "false", "no"}
         base_channels_body = {
             "size": 0,
             "aggs": {
@@ -762,6 +764,10 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
                 }
             },
         }
+        if not include_external:
+            base_channels_body["query"] = {
+                "bool": {"must_not": [{"term": {"external_reference": True}}]}
+            }
 
         def run_channels_request(field_name: str):
             body = json.loads(json.dumps(base_channels_body))  # deep copy
@@ -920,7 +926,7 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         use_fuzzy = parse_flag("fuzzy", True)
         use_phrase = parse_flag("phrase", True)
         use_query_string = parse_flag("query_string", False)
-        include_external = parse_flag("external", True)
+        include_external = parse_flag("external", False)
         if use_query_string:
             use_exact = use_fuzzy = use_phrase = False
 
@@ -1075,7 +1081,7 @@ def create_app(config: AppConfig = CONFIG) -> Flask:
         use_exact = parse_flag("exact", True)
         use_fuzzy = parse_flag("fuzzy", True)
         use_phrase = parse_flag("phrase", True)
-        include_external = parse_flag("external", True)
+        include_external = parse_flag("external", False)
         if use_query_string:
             use_exact = use_fuzzy = use_phrase = False
 
diff --git a/static/app.js b/static/app.js
index 328b2a1..9ba821c 100644
--- a/static/app.js
+++ b/static/app.js
@@ -141,7 +141,7 @@
     fuzzyToggle.checked = parseBoolParam("fuzzy", true);
     phraseToggle.checked = parseBoolParam("phrase", true);
     if (externalToggle) {
-      externalToggle.checked = parseBoolParam("external", true);
+      externalToggle.checked = parseBoolParam("external", false);
     }
     queryToggle.checked = parseBoolParam("query_string", false);
     applyQueryMode();
@@ -281,7 +281,11 @@
     });
     if (!collected.length) return null;
     const escaped = collected.map((id) => `"${escapeQueryValue(id)}"`);
-    return `${field}:(${escaped.join(" OR ")})`;
+    const variants = field.endsWith(".keyword")
+      ? [field]
+      : [`${field}.keyword`, field];
+    const clauses = variants.map((fname) => `${fname}:(${escaped.join(" OR ")})`);
+    return clauses.length > 1 ? `(${clauses.join(" OR ")})` : clauses[0];
   }
 
   async function loadChannels() {
@@ -290,7 +294,8 @@
       return;
     }
     try {
-      const res = await fetch("/api/channels");
+      const includeExternal = externalToggle ? externalToggle.checked : false;
+      const res = await fetch(`/api/channels?external=${includeExternal ? "1" : "0"}`);
       const data = await res.json();
       channelMap.clear();
       channelSelect.innerHTML = '<option value="">All Channels</option>';
@@ -1198,7 +1203,7 @@ async function updateFrequencyChart(term, channels, year, queryMode, toggles = {
   if (queryMode) {
     params.set("query_string", "1");
   }
-  const { exact = true, fuzzy = true, phrase = true, external = true } = toggles || {};
+  const { exact = true, fuzzy = true, phrase = true, external = false } = toggles || {};
   params.set("exact", exact ? "1" : "0");
   params.set("fuzzy", fuzzy ? "1" : "0");
   params.set("phrase", phrase ? "1" : "0");
@@ -1529,7 +1534,7 @@ async function updateFrequencyChart(term, channels, year, queryMode, toggles = {
     let exact = !!exactToggle.checked;
     let fuzzy = !!fuzzyToggle.checked;
     let phrase = !!phraseToggle.checked;
-    const includeExternal = externalToggle ? externalToggle.checked : true;
+    const includeExternal = externalToggle ? externalToggle.checked : false;
     if (queryMode) {
       exact = false;
       fuzzy = false;
@@ -1608,7 +1613,10 @@ async function updateFrequencyChart(term, channels, year, queryMode, toggles = {
   fuzzyToggle.addEventListener("change", () => { rememberToggleState(); runSearch(0); });
   phraseToggle.addEventListener("change", () => { rememberToggleState(); runSearch(0); });
   if (externalToggle) {
-    externalToggle.addEventListener("change", () => runSearch(0));
+    externalToggle.addEventListener("change", () => {
+      pendingChannelSelection = "";
+      loadChannels().then(() => runSearch(0));
+    });
   }
   if (queryToggle) {
     queryToggle.addEventListener("change", () => { applyQueryMode(); runSearch(0); });
diff --git a/static/index.html b/static/index.html
index f237563..cc1d437 100644
--- a/static/index.html
+++ b/static/index.html
@@ -82,7 +82,7 @@
             </div>
 
             <div class="toggle-item">
-              <input type="checkbox" id="externalToggle" checked />
+              <input type="checkbox" id="externalToggle" />
               <label for="externalToggle">External</label>
               <span class="toggle-help">Include externally referenced items.</span>
             </div>