From c62a0b57614e0637f60044c421a69448badfc2eb Mon Sep 17 00:00:00 2001
From: erikkaashoek <erik@kaashoek.com>
Date: Mon, 11 May 2020 08:06:01 +0200
Subject: [PATCH 1/2] Force reflevel with linear scales

---
 sa_core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sa_core.c b/sa_core.c
index 666dee2..aee302b 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -458,6 +458,9 @@ void set_offset(float offset)
 
 void set_scale(float s) {
   setting.scale = s;
+  if (setting.unit == U_VOLT || setting.unit == U_MWATT) {
+    set_reflevel(9 * s);
+  }
   set_trace_scale(0, s);
   set_trace_scale(1, s);
   set_trace_scale(2, s);

From 2667955977d3c713f527c40d0e0c364cdb3cad73 Mon Sep 17 00:00:00 2001
From: erikkaashoek <erik@kaashoek.com>
Date: Mon, 11 May 2020 11:56:12 +0200
Subject: [PATCH 2/2] Autorange for linear scales

---
 sa_core.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/sa_core.c b/sa_core.c
index aee302b..b26718d 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -1141,6 +1141,18 @@ static bool sweep(bool break_on_operation)
     }
   }
   if (!in_selftest && MODE_INPUT(setting.mode) && setting.auto_reflevel && max_index[0] > 0) {
+    if (setting.unit == U_VOLT || setting.unit == U_MWATT) {
+      float t = value(actual_t[max_index[0]]);
+      if (t < setting.reflevel / 2 || t> setting.reflevel) {
+        float m = 1;
+        t = t * 1.2;
+        while (t > 10) { m *= 10; t/=10; }
+        while (t < 1)  { m /= 10; t*=10; }
+        t = round(t);
+        set_scale(t*m / 9);
+        set_reflevel(t*m);
+      }
+    } else {
     if (value(actual_t[max_index[0]]) > setting.reflevel - setting.scale/2) {
       set_reflevel(setting.reflevel + setting.scale);
       redraw_request |= REDRAW_CAL_STATUS;
@@ -1154,6 +1166,7 @@ static bool sweep(bool break_on_operation)
       redraw_request |= REDRAW_CAL_STATUS;
       dirty = true;                               // Must be  above if(scandirty!!!!!)
     }
+    }
   }
 #if 1
   if (MODE_INPUT(setting.mode)) {