fix: the Yaesu power meter is not linear — calibrate it on three points

One point could not reveal the curve. Scaling 207 = 100 W straight down read
30 W where the radio showed 10, and 75 where it showed 50 — wrong everywhere
except at the single point it was fitted to.

Three readings taken against the rig's own display give the shape:

  raw  62 → 10 W
  raw 155 → 50 W
  raw 207 → 100 W

Interpolating between them reproduces the radio exactly at those points and stays
close in between. I did not fit a formula: three samples can be made to support
several curves, and the operator can check a table against their own meter.

Above the top the last segment's slope continues rather than clamping, so a rig
driving an amplifier does not sit pinned at 100 W. A test pins the measured pairs
and the monotonicity, so a later change that breaks them fails against the radio
rather than against taste.

changelog.json

@@ -3,7 +3,7 @@
     "version": "0.21.9",
     "date": "2026-07-28",
     "en": [
-      "Yaesu console meters are right: power now reads the meter that follows the RF (in watts, measured, not the power setting) and SWR shows the ratio itself. Both were reading the wrong index — the SWR bar sat near 80 on a perfect match. The bars also hold their peak for a moment before falling back, so they stay readable through the gaps between words in a CQ, in CW as in SSB.",
+      "Yaesu console meters are right: power now reads the meter that follows the RF (in watts, on a curve measured against the rig own display, not the power setting) and SWR shows the ratio itself. Both were reading the wrong index — the SWR bar sat near 80 on a perfect match. The bars also hold their peak for a moment before falling back, so they stay readable through the gaps between words in a CQ, in CW as in SSB.",
       "CW speed is now one setting wherever you change it: the Yaesu console slider and the CW panel drive the keyer that is actually sending, and the rig own keyer follows so its front panel agrees.",
       "Antenna Genius: port A no longer jumps onto port B antenna a few seconds after a change. Only one port can hold the transmit antenna, so the switch reports the same one on both — the display now follows each port own receive antenna.",
       "CW through the Yaesu keyer: a fifth CW engine sends your macros with the radio own keyer (CAT \"KY\"), for the FTDX101 / FT-991A / FT-710 family. An FTDX10 does not accept it — DAKY included — and OpsLog says so, pointing to the serial DTR keyer on the rig second COM port, which works.",
@@ -21,7 +21,7 @@
       "CQ and ITU zones you correct by hand in your profile stay corrected. They are derived from cty.dat, which gives the zones of the whole entity — in a country spanning several, the automatic value is wrong and it came back at every restart. They now only fill in when empty, and recompute when the callsign or grid changes."
     ],
     "fr": [
-      "Les mesures de la console Yaesu sont justes : la puissance lit l'instrument qui suit la HF (en watts mesurés, et non le réglage de puissance) et le ROS affiche le rapport lui-même. Les deux lisaient le mauvais index — la barre de ROS restait vers 80 sur une antenne parfaite. Les barres retiennent aussi leur crête un instant avant de redescendre : elles restent lisibles pendant les silences entre les mots d’un CQ, en CW comme en phonie.",
+      "Les mesures de la console Yaesu sont justes : la puissance lit l'instrument qui suit la HF (en watts, sur une courbe relevée face à l'affichage de la radio, et non le réglage de puissance) et le ROS affiche le rapport lui-même. Les deux lisaient le mauvais index — la barre de ROS restait vers 80 sur une antenne parfaite. Les barres retiennent aussi leur crête un instant avant de redescendre : elles restent lisibles pendant les silences entre les mots d’un CQ, en CW comme en phonie.",
       "La vitesse CW est désormais un réglage unique où que vous la changiez : le curseur de la console Yaesu et le panneau CW pilotent le manipulateur qui émet réellement, et le keyer interne de la radio suit pour que sa façade affiche la même valeur.",
       "Antenna Genius : le port A ne bascule plus sur l'antenne du port B quelques secondes après un changement. Un seul port peut porter l'antenne d'émission, le switch renvoie donc la même sur les deux — l'affichage suit désormais l'antenne de réception propre à chaque port.",
       "CW par le keyer Yaesu : un cinquième moteur CW envoie vos macros avec le keyer de la radio (CAT « KY »), pour la famille FTDX101 / FT-991A / FT-710. Un FTDX10 ne l'accepte pas — DAKY compris — et OpsLog le dit en renvoyant vers le keyer série DTR sur son second port COM, qui fonctionne.",