diff --git a/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt b/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt
index cc281ed5..8126ba48 100644
--- a/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt
+++ b/core/data/src/main/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocol.kt
@@ -330,12 +330,13 @@ object IcomCivProtocol {
 
     /**
      * Parse frequency + mode from a CMD_READ_FREQ reply payload.
-     * Payload layout after stripping command byte: [5 freq bytes] [mode byte] [filter byte]
+     * Payload layout after stripping command byte: [5 freq bytes]
+     * The IC-705 does not include a mode byte; if one is present it is parsed, otherwise mode is empty.
      */
     fun parseFreqModePayload(payload: ByteArray): Pair<Long, String>? {
-        if (payload.size < 6) return null
+        if (payload.size < 5) return null
         val freqHz = decodeFrequencyBcd(payload.copyOfRange(0, 5))
-        val mode   = BYTE_TO_MODE[payload[5]] ?: return null
+        val mode   = if (payload.size > 5) BYTE_TO_MODE[payload[5]] ?: return null else ""
         return freqHz to mode
     }
 
diff --git a/core/data/src/test/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocolTest.kt b/core/data/src/test/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocolTest.kt
new file mode 100644
index 00000000..e6e58f08
--- /dev/null
+++ b/core/data/src/test/java/com/rtbishop/look4sat/core/data/framework/IcomCivProtocolTest.kt
@@ -0,0 +1,33 @@
+package com.rtbishop.look4sat.core.data.framework
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class IcomCivProtocolTest {
+
+    private fun bytes(vararg values: Int) = ByteArray(values.size) { values[it].toByte() }
+
+    @Test
+    fun parseFreqModePayload_ic705ReadFreqReply() {
+        // Reply captured from an IC-705 to CMD 0x03: frequency only, no mode byte
+        val reply = bytes(0xFE, 0xFE, 0xE0, 0xA4, 0x03, 0x60, 0x74, 0x95, 0x45, 0x01, 0xFD)
+        val response = IcomCivProtocol.parseResponse(reply, IcomCivProtocol.CMD_READ_FREQ)
+        assertNotNull(response)
+        assertEquals(145957460L to "", IcomCivProtocol.parseFreqModePayload(response!!.payload))
+    }
+
+    @Test
+    fun parseFreqModePayload_withModeByte() {
+        assertEquals(
+            435611000L to "USB",
+            IcomCivProtocol.parseFreqModePayload(bytes(0x00, 0x10, 0x61, 0x35, 0x04, 0x01, 0x01))
+        )
+    }
+
+    @Test
+    fun parseFreqModePayload_tooShort() {
+        assertNull(IcomCivProtocol.parseFreqModePayload(bytes(0x60, 0x74, 0x95, 0x45)))
+    }
+}