diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
index f043566..0a16931 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
@@ -582,16 +582,16 @@ let sigStrengthUnitIdx = loadSetting("sigStrengthUnit", 0);
 function formatSigStrength(dbm) {
   if (!Number.isFinite(dbm)) return "--";
   const unit = SIG_STRENGTH_UNITS[sigStrengthUnitIdx] || "dBFS";
-  if (unit === "dBm") return `${dbm} dBm`;
+  if (unit === "dBm") return `${dbm.toFixed(1)} dBm`;
   if (unit === "dBf") {
     // dBf = dBm + 107 (referenced to 1 femtowatt across 50 Ω)
     const dbf = dbm + 107;
-    return `${dbf.toFixed(0)} dBf`;
+    return `${dbf.toFixed(1)} dBf`;
   }
   // dBFS: map receiver range to a full-scale reference
   // Typical receiver: -140 dBm (noise floor) to 0 dBm (full scale)
   const dbfs = Math.max(-140, Math.min(0, dbm));
-  return `${dbfs} dBFS`;
+  return `${dbfs.toFixed(1)} dBFS`;
 }
 
 function refreshSigStrengthDisplay() {
@@ -9199,7 +9199,7 @@ function startSpectrumStreaming() {
       vchanRdsById = next;
       vchanSignalDbById = nextSig;
       if (typeof vchanActiveId !== "undefined" && vchanActiveId && nextSig.has(vchanActiveId)) {
-        sigLastDbm = Math.round(nextSig.get(vchanActiveId));
+        sigLastDbm = nextSig.get(vchanActiveId);
         refreshSigStrengthDisplay();
       }
       updateRdsPsOverlay(primaryRds);
diff --git a/src/trx-core/src/rig/controller/machine.rs b/src/trx-core/src/rig/controller/machine.rs
index 9a003e0..9f27708 100644
--- a/src/trx-core/src/rig/controller/machine.rs
+++ b/src/trx-core/src/rig/controller/machine.rs
@@ -307,7 +307,7 @@ impl RigMachineState {
                 tx_en: true,
                 vfo: data.vfo.clone(),
                 tx: data.tx.clone(),
-                rx: Some(RigRxStatus { sig: Some(0) }),
+                rx: Some(RigRxStatus { sig: Some(0.0) }),
                 lock: Some(data.locked),
             }),
             _ => None,
diff --git a/src/trx-core/src/rig/mod.rs b/src/trx-core/src/rig/mod.rs
index d3359fe..4bef2e3 100644
--- a/src/trx-core/src/rig/mod.rs
+++ b/src/trx-core/src/rig/mod.rs
@@ -125,6 +125,15 @@ pub trait RigCat: Rig + Send {
         &'a mut self,
     ) -> Pin<Box<dyn Future<Output = DynResult<u8>> + Send + 'a>>;
 
+    /// Return precise signal strength in dBm/dBFS as a float.
+    /// Backends with continuous measurements (e.g. SDR) override this
+    /// to bypass the coarse 0..15 quantisation of `get_signal_strength`.
+    fn get_signal_strength_db<'a>(
+        &'a mut self,
+    ) -> Pin<Box<dyn Future<Output = Option<f64>> + Send + 'a>> {
+        Box::pin(std::future::ready(None))
+    }
+
     fn get_tx_power<'a>(&'a mut self) -> Pin<Box<dyn Future<Output = DynResult<u8>> + Send + 'a>>;
 
     fn get_tx_limit<'a>(&'a mut self) -> Pin<Box<dyn Future<Output = DynResult<u8>> + Send + 'a>>;
@@ -343,9 +352,9 @@ pub struct RigTxStatus {
     pub alc: Option<u8>,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct RigRxStatus {
-    pub sig: Option<i32>,
+    pub sig: Option<f64>,
 }
 
 /// Configurable control settings that can be pushed to the rig.
diff --git a/src/trx-server/src/rig_task.rs b/src/trx-server/src/rig_task.rs
index 4320cbc..3feaf4f 100644
--- a/src/trx-server/src/rig_task.rs
+++ b/src/trx-server/src/rig_task.rs
@@ -887,7 +887,9 @@ async fn refresh_state_from_cat(rig: &mut Box<dyn RigCat>, state: &mut RigState)
     state.status.vfo = vfo;
 
     if state.status.tx_en {
-        state.status.rx.get_or_insert(RigRxStatus { sig: None }).sig = Some(0);
+        state.status.rx.get_or_insert(RigRxStatus { sig: None }).sig = Some(0.0);
+    } else if let Some(db) = rig.get_signal_strength_db().await {
+        state.status.rx.get_or_insert(RigRxStatus { sig: None }).sig = Some(db);
     } else if let Ok(meter) = rig.get_signal_strength().await {
         let sig = map_signal_strength(&state.status.mode, meter);
         state.status.rx.get_or_insert(RigRxStatus { sig: None }).sig = Some(sig);
@@ -1015,12 +1017,12 @@ async fn prime_vfo_state(
 }
 
 /// Map raw signal strength to S-meter value based on mode.
-fn map_signal_strength(mode: &RigMode, raw: u8) -> i32 {
+fn map_signal_strength(mode: &RigMode, raw: u8) -> f64 {
     // FT-817 returns 0-15 for signal strength
     // Map to approximate dBm / S-units
     match mode {
-        RigMode::FM | RigMode::WFM | RigMode::AIS | RigMode::VDES => -120 + (raw as i32 * 6),
-        _ => -127 + (raw as i32 * 6),
+        RigMode::FM | RigMode::WFM | RigMode::AIS | RigMode::VDES => -120.0 + (raw as f64 * 6.0),
+        _ => -127.0 + (raw as f64 * 6.0),
     }
 }
 
diff --git a/src/trx-server/trx-backend/trx-backend-soapysdr/src/dsp/channel.rs b/src/trx-server/trx-backend/trx-backend-soapysdr/src/dsp/channel.rs
index c4698ec..bd8b294 100644
--- a/src/trx-server/trx-backend/trx-backend-soapysdr/src/dsp/channel.rs
+++ b/src/trx-server/trx-backend/trx-backend-soapysdr/src/dsp/channel.rs
@@ -757,7 +757,13 @@ impl ChannelDsp {
         }
 
         // Signal strength measurement (before AGC).
+        //
+        // The decimated samples carry the total power of the channel bandwidth,
+        // which is higher than the per-bin spectral density shown on the
+        // spectrum display by approximately 10·log10(decim_factor).  Subtract
+        // that so the meter and the spectrum peak agree.
         {
+            let decim_correction = 10.0 * (self.decim_factor as f32).max(1.0).log10();
             if self.mode == RigMode::WFM {
                 // WFM: smooth envelope power directly.
                 // FM is constant-envelope, so I²+Q² is inherently stable
@@ -769,7 +775,8 @@ impl ChannelDsp {
                     let pwr = s.re * s.re + s.im * s.im;
                     self.carrier_iq_i += alpha * (pwr - self.carrier_iq_i);
                 }
-                self.last_signal_db = 10.0 * self.carrier_iq_i.max(1e-12).log10();
+                self.last_signal_db =
+                    10.0 * self.carrier_iq_i.max(1e-12).log10() - decim_correction;
             } else {
                 // Other modes: peak IQ magnitude with EMA smoothing.
                 const SIGNAL_EMA_ALPHA: f32 = 0.4;
@@ -777,7 +784,7 @@ impl ChannelDsp {
                     .iter()
                     .map(|s| s.re * s.re + s.im * s.im)
                     .fold(0.0_f32, f32::max);
-                let peak_db = 10.0 * peak_power.max(1e-12).log10();
+                let peak_db = 10.0 * peak_power.max(1e-12).log10() - decim_correction;
                 self.last_signal_db += SIGNAL_EMA_ALPHA * (peak_db - self.last_signal_db);
             }
         }
diff --git a/src/trx-server/trx-backend/trx-backend-soapysdr/src/lib.rs b/src/trx-server/trx-backend/trx-backend-soapysdr/src/lib.rs
index d73f402..5e38227 100644
--- a/src/trx-server/trx-backend/trx-backend-soapysdr/src/lib.rs
+++ b/src/trx-server/trx-backend/trx-backend-soapysdr/src/lib.rs
@@ -567,6 +567,19 @@ impl RigCat for SoapySdrRig {
         })
     }
 
+    fn get_signal_strength_db<'a>(
+        &'a mut self,
+    ) -> Pin<Box<dyn std::future::Future<Output = Option<f64>> + Send + 'a>> {
+        Box::pin(async move {
+            self.pipeline
+                .channel_dsps
+                .read()
+                .unwrap()
+                .get(self.primary_channel_idx)
+                .and_then(|dsp| dsp.lock().ok().map(|d| d.signal_db() as f64))
+        })
+    }
+
     // -- TX / unsupported methods -------------------------------------------
 
     fn set_ptt<'a>(