From 789b0ad2d10a5274af798c3a1c45f8ee5a27eedc Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Sat, 12 Dec 2020 16:10:12 +0100
Subject: Move to 6MHz IF

---
 freqplan.py             | 26 ++++++++++++--------------
 kicad/baseband.sch      |  6 ++++--
 sw/picardy/src/state.rs |  6 +++---
 3 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/freqplan.py b/freqplan.py
index 9272c41..e01e6e5 100644
--- a/freqplan.py
+++ b/freqplan.py
@@ -1,39 +1,37 @@
 #!/usr/bin/env python3
 #
-# OUTDATED
-# This document is outdated because the VHF LO is not generated
-# externally
 
 from fractions import Fraction
 from math import floor
 
 xtal = 25
+PLLa_mult = 35
 
 print()
-print("# 116MHz and 4.915 MHz on PLLa")
+print("# 6000.694 - 2.200 kHz on PLLa")
 
-PLLa = xtal * 32
-print(f"PLLa = xtal * 32 = {PLLa} MHz")
+PLLa = xtal * PLLa_mult
+print(f"PLLa = xtal * {PLLa_mult} = {PLLa} MHz")
+
+if PLLa < 600 or PLLa > 900:
+    print(f"Error PLL {PLLA} out of bounds")
 
 # x/y = a + b/y
 # a = floor(x/y)
 # b = x - (a * y)
 
-f1 = 116
-a = floor(PLLa / f1)
-b = PLLa - (a * f1)
-div1 = Fraction(b, f1)
-print(f"CLK1: f1 = PLLa / ({a} + {div1.numerator} / {div1.denominator}) = {f1}")
-
-f2 = 4.91521
+f2 = (6000.694 - 2.200) / 1000
 a = floor(PLLa / f2)
 b = PLLa - (a * f2)
 div1 = Fraction(round(b * 10000), round(f2 * 10000))
 print(f"CLK2: f2 = PLLa / ({a} + {div1.numerator} / {div1.denominator}) = {f2}")
 
+VHF_LO = 114.285 # Fixed XTAL
+BAND_EDGE_LOW = 144 - VHF_LO
+BAND_EDGE_HIGH = 145 - VHF_LO
 
 print()
-print("# VFO between 23 and 25 MHz on PLLb")
+print(f"# VFO between {BAND_EDGE_LOW:6.6} and {BAND_EDGE_HIGH:6.6} MHz on PLLb")
 
 def calculate(frequency):
     divider = floor(900000000 / frequency) # Calculate the division ratio. 900,000,000 is the maximum internal
diff --git a/kicad/baseband.sch b/kicad/baseband.sch
index 0b1fd55..98f8bad 100644
--- a/kicad/baseband.sch
+++ b/kicad/baseband.sch
@@ -5,7 +5,7 @@ $Descr A4 11693 8268
 encoding utf-8
 Sheet 3 6
 Title "Picardy Anglian Mashup"
-Date "2020-03-18"
+Date "2020-12-12"
 Rev ""
 Comp "HB9EGM"
 Comment1 ""
@@ -702,7 +702,7 @@ L Device:C_Small C329
 U 1 1 5E3C120C
 P 6400 3150
 F 0 "C329" H 6308 3104 50  0000 R CNN
-F 1 "220pF" H 6308 3195 50  0000 R CNN
+F 1 "27pF" H 6308 3195 50  0000 R CNN
 F 2 "Capacitor_SMD:C_0603_1608Metric_Pad1.05x0.95mm_HandSolder" H 6400 3150 50  0001 C CNN
 F 3 "~" H 6400 3150 50  0001 C CNN
 F 4 "0" H 6400 3150 50  0001 C CNN "Need_order"
@@ -3231,4 +3231,6 @@ F 6 "47uF" H 10300 6050 50  0001 C CNN "OriginalValue"
 	1    10300 6050
 	-1   0    0    -1  
 $EndComp
+Text Notes 950  6100 0    47   ~ 0
+Currently assembled:\n4 6MHz crystals\nY301=Y306=12pF\nC310=C365=10pF\nC364=12pF\nTODO adapt L310
 $EndSCHEMATC
diff --git a/sw/picardy/src/state.rs b/sw/picardy/src/state.rs
index 466fd32..b29b8b4 100644
--- a/sw/picardy/src/state.rs
+++ b/sw/picardy/src/state.rs
@@ -1,8 +1,8 @@
 pub const VHF_BAND_EDGE : u32 = 144_000_000;
 pub const VHF_INITIAL_VFO : u32 = 144_300_000;
-pub const VHF_LO : u32 = 114_285_000;
-pub const BFO_LSB : u32 = 4_915_940;
-pub const BFO_USB : u32 = 4_914_910;
+pub const VHF_LO : u32 = 114_286_400;
+pub const BFO_LSB : u32 = 6_000_700 + 2_200;
+pub const BFO_USB : u32 = 6_000_700 - 2_200;
 
 // Defines which parameter is changed by the encoder
 #[derive(Clone, Copy, PartialEq, Eq)]
-- 
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