Homebrew CW Rig

Please see the YouTube videos for an explanation on the code and circuits:
https://www.youtube.com/channel/UCSNPW3_gzuMJcX_ErBZTv2g/

Crystal Filter

IF Amps

Antenna Amp, 700Hz LPF

Initial Class E RF Amplifier Experiment (see YouTube video for explanation)

Final Class E Amplifier

Code

#include <LiquidCrystal_I2C.h>
#include <si5351.h>

const long band80mStart = 3500000;    // start of 80m
const long band80mEnd = 3900000;      // end of 80m
volatile uint32_t FilterCentreFreq = 8996500;
volatile uint32_t BFO = 8997243;      // Filter centre freq plus offset to get 700Hz AF out.

volatile long freq = 3525000;         // this is a variable (changes) - set it to the beginning of the band
volatile long radix = 100;            // how much to change the frequency by, clicking the rotary encoder will change this.
volatile long oldfreq = 0;
volatile long currentfreq = 0;
volatile int updatedisplay = 0;
volatile int band = 0;                // 0=80m, 1=40m
volatile int oldband = 0;

// Rotary encoder pins and other inputs
static const int rotAPin = 2;
static const int rotBPin = 3;
static const int pushPin = 4;

// Rotary encoder variables, used by interrupt routines
volatile int rotState = 0;
volatile int rotAval = 1;
volatile int rotBval = 1;

// Instantiate the Objects
LiquidCrystal_I2C lcd(0x27, 16, 2);
Si5351 si5351;

// 700Hz Osc
static const int Osc = 11;
static const int TuneSw = 9;

// Morse Key
static const int Key = 8;
unsigned long BreakInTimer;
unsigned long BreakInDelay = 1000;    //1000mS - 1.0Sec

// Relays
static const int AntRelay = 7;
static const int PowerRelay = 6;

void setup()
{
  // Set up I/O Pins
  pinMode(rotAPin, INPUT_PULLUP);
  pinMode(rotBPin, INPUT_PULLUP);
  pinMode(pushPin, INPUT_PULLUP);
  pinMode(TuneSw, INPUT_PULLUP);
  pinMode(Key, INPUT_PULLUP);
  pinMode(AntRelay, OUTPUT);
  pinMode(PowerRelay, OUTPUT);
  pinMode(Osc, OUTPUT);

  digitalWrite(AntRelay, HIGH);         // Default to Rx
  digitalWrite(PowerRelay, HIGH);       // Default to Rx

  // Set up interrupt pins
  attachInterrupt(digitalPinToInterrupt(rotAPin), ISRrotAChange, CHANGE);
  attachInterrupt(digitalPinToInterrupt(rotBPin), ISRrotBChange, CHANGE);

  // Initialize the display
  lcd.begin();
  lcd.backlight();
  lcd.cursor();

  // Initialize the DDS
  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);
  si5351.set_correction(-400, SI5351_PLL_INPUT_XO);       // Set to specific Si5351 calibration number
  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_8MA);
  si5351.drive_strength(SI5351_CLK1, SI5351_DRIVE_8MA);
  si5351.drive_strength(SI5351_CLK2, SI5351_DRIVE_8MA);
  si5351.output_enable(SI5351_CLK1, 0);                   // Turn off CW carrier

  // Update display and send start frequency
  UpdateDisplay();
  SendFrequency();
}


void loop()
{
  if (digitalRead(Key) == LOW)                // Check to see if CW key down
  {
    BreakInTimer = millis();                  // Reset the break in timer
    digitalWrite(AntRelay, LOW);              // Swap over the antenna to Tx
    digitalWrite(PowerRelay, LOW);            // Rx 12VDC = 0, Tx 12VDC = 12
    delay(25);                                // Allow time for relays to swap over (Spec sheet 10mS)
    si5351.output_enable(SI5351_CLK1, 1);     // Get ready to transmit CW carrier
    SendFrequency();                          // Send CW carrier
  }
  else                                        // Key up
  {
    si5351.output_enable(SI5351_CLK1, 0);     // Turn off the CW carrier
  }

  if ((millis() - BreakInTimer) >= BreakInDelay)    // Check break in timer
  {
    digitalWrite(AntRelay, HIGH);             // Swap over the antenna to Rx
    digitalWrite(PowerRelay, HIGH);           // Rx 12VDC = 12, Tx 12VDC = 0
  }

  if (digitalRead(TuneSw) == LOW)             // Check tune switch
    tone(Osc, 700);                           // Turn on the 700Hz tome
  else
    noTone(Osc);                              // Turn off the 700Hz tome

  currentfreq = getfreq();                    // Interrupt safe method to get the current frequency

  if (currentfreq != oldfreq)
  {
    UpdateDisplay();
    SendFrequency();
    oldfreq = currentfreq;
  }

  if (!digitalRead(pushPin)) {
    delay(10);
    while (!digitalRead(pushPin))
    {
      if (updatedisplay == 1)
      {
        UpdateDisplay();
        updatedisplay = 0;
      }
    }
    delay(50);
  }
}


long getfreq()
{
  long temp_freq;
  cli();
  temp_freq = freq;
  sei();
  return temp_freq;
}


// Interrupt routines
void ISRrotAChange()
{
  if (digitalRead(rotAPin))
  {
    rotAval = 1;
    UpdateRot();
  }
  else
  {
    rotAval = 0;
    UpdateRot();
  }
}


void ISRrotBChange()
{
  if (digitalRead(rotBPin))
  {
    rotBval = 1;
    UpdateRot();
  }
  else
  {
    rotBval = 0;
    UpdateRot();
  }
}


void UpdateRot()
{
  switch (rotState)
  {

    case 0:                                         // Idle state, look for direction
      if (!rotBval)
        rotState = 1;                               // CW 1
      if (!rotAval)
        rotState = 11;                              // CCW 1
      break;

    case 1:                                         // CW, wait for A low while B is low
      if (!rotBval)
      {
        if (!rotAval)
        {
          // either increment radixindex or freq
          if (digitalRead(pushPin) == LOW)
          {
            updatedisplay = 1;
            if (radix == 1000000)
              radix = 100000;
            else if (radix == 100000)
              radix = 10000;
            else if (radix == 10000)
              radix = 1000;
            else if (radix == 1000)
              radix = 100;
            else if (radix == 100)
              radix = 10;
            else if (radix == 10)
              radix = 1;
            else
              radix = 1000000;
          } else
          {
            freq = (freq + radix);
            if (freq > 3900000)
              freq = 3900000;
          }
          rotState = 2;                             // CW 2
        }
      } else
      {
        if (rotAval)
          rotState = 0;                             // It was just a glitch on B, go back to start
      }
      break;

    case 2:                                         // CW, wait for B high
      if (rotBval)
        rotState = 3;                               // CW 3
      break;

    case 3:                                         // CW, wait for A high
      if (rotAval)
        rotState = 0;                               // back to idle (detent) state
      break;

    case 11:                                        // CCW, wait for B low while A is low
      if (!rotAval)
      {
        if (!rotBval)
        {
          // either decrement radixindex or freq
          if (digitalRead(pushPin) == LOW)
          {
            updatedisplay = 1;
            if (radix == 1)
              radix = 10;
            else if (radix == 10)
              radix = 100;
            else if (radix == 100)
              radix = 1000;
            else if (radix == 1000)
              radix = 10000;
            else if (radix == 10000)
              radix = 100000;
            else if (radix == 100000)
              radix = 1000000;
            else
              radix = 1;
          } else
          {
            freq = (freq - radix);
            if (freq < 3500000)
              freq = 3500000;
          }
          rotState = 12;                            // CCW 2
        }
      } else
      {
        if (rotBval)
          rotState = 0;                             // It was just a glitch on A, go back to start
      }
      break;

    case 12:                                        // CCW, wait for A high
      if (rotAval)
        rotState = 13;                              // CCW 3
      break;

    case 13:                                        // CCW, wait for B high
      if (rotBval)
        rotState = 0;                               // back to idle (detent) state
      break;
  }
}



void UpdateDisplay()
{
  lcd.setCursor(0, 0);
  lcd.print("        ");
  lcd.setCursor(0, 0);
  lcd.print(freq);
  lcd.setCursor(10, 0);
  lcd.print("ZL2CTM");

  if (radix == 1)
    lcd.setCursor(6, 0);
  if (radix == 10)
    lcd.setCursor(5, 0);
  if (radix == 100)
    lcd.setCursor(4, 0);
  if (radix == 1000)
    lcd.setCursor(3, 0);
  if (radix == 10000)
    lcd.setCursor(2, 0);
  if (radix == 100000)
    lcd.setCursor(1, 0);
  if (radix == 1000000)
    lcd.setCursor(0, 0);
}


void SendFrequency()
{
  // VFO
  si5351.set_freq(((freq + FilterCentreFreq) * 100ULL), SI5351_CLK0);

  // BFO
  si5351.set_freq((BFO * 100ULL), SI5351_CLK2);

  // Transmit CW carrier
  si5351.set_freq(((freq - 43)  * 100ULL), SI5351_CLK1);         // 43Hz to align Tx and Rx
}

Homebrew DSB-SC Rig

AF Amps Ideas

The AF amp now has a pi filter on the input made up of 100nF - 1mH - 100nF

That removes the high freq noise.

Ant RF Amp

Mic Amp

Test Low Power RF Amplifier

Out of the junk box hence the 13.8VDC VCC.

Initial code for the radio. Please see the YouTube video for an explanation:

#include <LiquidCrystal_I2C.h>

#include <si5351.h>

const long band80mStart = 3500000;    // start of 80m

const long band80mEnd = 3900000;      // end of 80m

const long band40mStart = 7000000;    // start of 40m

const long band40mEnd = 7300000;      // end of 40m

volatile long freq = 3700000;         // this is a variable (changes) - set it to the beginning of the band

volatile long radix = 1000;           // how much to change the frequency by, clicking the rotary encoder will change this.

volatile long oldfreq = 0;

volatile long old80mfreq = 3700000;

volatile long old40mfreq = 7100000;

volatile long currentfreq = 0;

volatile int updatedisplay = 0;

volatile int band = 0;                // 0=80m, 1=40m

volatile int oldband = 0;

// Rotary encoder pins and other inputs

static const int rotAPin = 2;

static const int rotBPin = 3;

static const int pushSwPin = 4;

// Band switch

static const int BandSwPin = 5;

// Rotary encoder variables, used by interrupt routines

volatile int rotState = 0;

volatile int rotAval = 1;

volatile int rotBval = 1;

// Instantiate the Objects

LiquidCrystal_I2C lcd(0x27, 16, 2);

Si5351 si5351;

void setup()

{

  // Set up frequency and radix switches

  pinMode(rotAPin, INPUT_PULLUP);

  pinMode(rotBPin, INPUT_PULLUP);

  pinMode(pushSwPin, INPUT_PULLUP);

  pinMode(BandSwPin, INPUT_PULLUP);

  // Set up interrupt pins

  attachInterrupt(digitalPinToInterrupt(rotAPin), ISRrotAChange, CHANGE);

  attachInterrupt(digitalPinToInterrupt(rotBPin), ISRrotBChange, CHANGE);

  // Initialize the display

  lcd.begin();

  lcd.backlight();

  lcd.cursor();

  // Initialize the Si5351

  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);

  si5351.set_correction(191, SI5351_PLL_INPUT_XO);

  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);

  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_8MA);

  // Update display and send start frequency

  UpdateDisplay();

  SendFrequency();

}

void loop()

{

  // Check to see if the freq has changed

  currentfreq = getfreq();                    // Interrupt safe method to get the current frequency

  if (currentfreq != oldfreq)

  {

    UpdateDisplay();

    SendFrequency();

    oldfreq = currentfreq;

  }

  // Check the rotary encoder (radix) swith

  if (digitalRead(pushSwPin) == LOW)           // Read the rotary encoder switch

  {

    delay(10);

    while (digitalRead(pushSwPin) == LOW)

    {

      if (updatedisplay == 1)

      {

        UpdateDisplay();

        updatedisplay = 0;

      }

    }

    delay(50);

  }

  // Check the band swith

  if (digitalRead(BandSwPin) == LOW)

    band = 1;                                  // 1=40m

  else

    band = 0;                                  // 0=80m

  if (band != oldband)                         // Only update the display on band change

  {

    if (band == 0)                             // Now 80m was 40m

    {

      old40mfreq = freq;                       // Store old 40m freq

      freq = old80mfreq;                       // Recall old 40m freq

    }

    if (band == 1)                             // Now 40m was 80m

    {

      old80mfreq = freq;                       // Store old 80m freq

      freq = old40mfreq;                       // Recall old 40m freq

    }

    UpdateDisplay();

    oldband = band;

  }

}

long getfreq()

{

  long temp_freq;

  cli();

  temp_freq = freq;

  sei();

  return temp_freq;

}

// Interrupt routines

void ISRrotAChange()

{

  if (digitalRead(rotAPin))

  {

    rotAval = 1;

    UpdateRot();

  }

  else

  {

    rotAval = 0;

    UpdateRot();

  }

}

void ISRrotBChange()

{

  if (digitalRead(rotBPin))

  {

    rotBval = 1;

    UpdateRot();

  }

  else

  {

    rotBval = 0;

    UpdateRot();

  }

}

// Determine which way the rotary encoder is rotating and action as required

void UpdateRot()

{

  switch (rotState)

  {

    case 0:                                         // Idle state, look for direction

      if (!rotBval)

        rotState = 1;                               // CW 1

      if (!rotAval)

        rotState = 11;                              // CCW 1

      break;

    case 1:                                         // CW, wait for A low while B is low

      if (!rotBval)

      {

        if (!rotAval)

        {

          // either increment the radix or freq

          if (digitalRead(pushSwPin) == LOW)

          {

            updatedisplay = 1;

            if (radix == 1000000)

              radix = 100000;

            else if (radix == 100000)

              radix = 10000;

            else if (radix == 10000)

              radix = 1000;

            else if (radix == 1000)

              radix = 100;

            else if (radix == 100)

              radix = 10;

            else if (radix == 10)

              radix = 1;

            else

              radix = 1000000;

          }

          else

          {

            freq = (freq + radix);

            if (band == 0)                          // 80m

              if (freq > band80mEnd)

                freq = band80mEnd;

            if (band == 1)                          // 40m

              if (freq > band40mEnd)

                freq = band40mEnd;

          }

          rotState = 2;                             // CW 2

        }

      }

      else if (rotAval)

        rotState = 0;                               // It was just a glitch on B, go back to start

      break;

    case 2:                                         // CW, wait for B high

      if (rotBval)

        rotState = 3;                               // CW 3

      break;

    case 3:                                         // CW, wait for A high

      if (rotAval)

        rotState = 0;                               // back to idle (detent) state

      break;

    case 11:                                        // CCW, wait for B low while A is low

      if (!rotAval)

      {

        if (!rotBval)

        {

          // either decrement the radix or freq

          if (digitalRead(pushSwPin) == LOW)

          {

            updatedisplay = 1;

            if (radix == 1)

              radix = 10;

            else if (radix == 10)

              radix = 100;

            else if (radix == 100)

              radix = 1000;

            else if (radix == 1000)

              radix = 10000;

            else if (radix == 10000)

              radix = 100000;

            else if (radix == 100000)

              radix = 1000000;

            else

              radix = 1;

          }

          else

          {

            freq = (freq - radix);

            if (band == 0)                          // 80m

              if (freq < band80mStart)

                freq = band80mStart;

            if (band == 1)                          // 40m

              if (freq < band40mStart)

                freq = band40mStart;

          }

          rotState = 12;                            // CCW 2

        }

      }

      else if (rotBval)

        rotState = 0;                               // It was just a glitch on A, go back to start

      break;

    case 12:                                        // CCW, wait for A high

      if (rotAval)

        rotState = 13;                              // CCW 3

      break;

    case 13:                                        // CCW, wait for B high

      if (rotBval)

        rotState = 0;                               // back to idle (detent) state

      break;

  }

}

void UpdateDisplay()

{

  lcd.setCursor(0, 0);

  lcd.print("        ");

  lcd.setCursor(0, 0);

  lcd.print(freq);

  lcd.setCursor(10, 0);

  lcd.print("ZL2CTM");

  if (radix == 1)

    lcd.setCursor(6, 0);

  if (radix == 10)

    lcd.setCursor(5, 0);

  if (radix == 100)

    lcd.setCursor(4, 0);

  if (radix == 1000)

    lcd.setCursor(3, 0);

  if (radix == 10000)

    lcd.setCursor(2, 0);

  if (radix == 100000)

    lcd.setCursor(1, 0);

  if (radix == 1000000)

    lcd.setCursor(0, 0);

}

void SendFrequency()

{

  si5351.set_freq((freq * 100ULL), SI5351_CLK0);

}

40m SSB Tramping Rig

Please see my YouTube channel for details of the build.

http://www.youtube.com/c/CharlieMorrisZL2CTM

2N3904 Antenna Amplifier (initial)

Voltage gain is set for 4 using Rdegen

J310 Antenna Amplifer

First need to determine Vp and Idss

2N3904 Antenna Amplifier (final)

Note, T2 is now a 10:5

7MHz BandPass Filter

2N3904 IF Amplifiers

 Relay and Crystal Configuration

High side versus low side injection

Initial RF Power Amplifier Driver

Software

#include <Wire.h>

#include <SPI.h>

#include <TM1637Display.h>

#include <si5351.h>

#include "LowPower.h"

const uint32_t bandStart = 7000000;   // start of 40m

const uint32_t bandEnd = 7300000;     // end of 40m

const uint32_t bandInit = 7100000;    // where to initially set the frequency

volatile long currentfreq = 0;

volatile long oldfreq = 0;

volatile int currentmode = 0;

volatile int oldmode = 0;

volatile uint32_t freq = bandInit ;     // this is a variable (changes) - set it to the beginning of the band

volatile uint32_t radix = 1000;         // how much to change the frequency by, clicking the rotary encoder will change this.

//const uint32_t BFO_freq = 9000000;      // Low side injection use 9000000;

const uint32_t BFO_freq = 8996400;      // High side injection use 8996400;

// Rotary encoder pins and other inputs

static const int rotBPin = 2;

static const int rotAPin = 3;

static const int pushPin = 4;

static const int PTTInput = 9;

static const int brightnessPin = A3;

static const int tunespeedLED = A2;

static const int gnd = 10;

static const int vcc = 11;

static const int DIO = 12;

static const int CLK = 13;

// Rotary encoder variables, used by interrupt routines

volatile int rotState = 0;

volatile int rotAval = 1;

volatile int rotBval = 1;

volatile long remainder = 0;

volatile long OnesHz = 0;

volatile long TensHz = 0;

volatile long HundredsHz = 0;

volatile long OneskHz = 0;

volatile long TenskHz = 0;

volatile long HundredskHz = 0;

volatile long OnesMHz = 0;

volatile long TensMHz = 0;

volatile int Brightness = 3;

volatile int batterySave = 0;

// Instantiate the Objects

TM1637Display display(CLK, DIO);    // CLK, DIO

Si5351 si5351;

void setup()

{

  // Set up frequency and radix switches

  pinMode(rotAPin, INPUT);

  pinMode(rotBPin, INPUT);

  pinMode(pushPin, INPUT);

  pinMode(brightnessPin, INPUT);

  pinMode(gnd, OUTPUT);

  pinMode(tunespeedLED, OUTPUT);

  pinMode(vcc, OUTPUT);

  pinMode(PTTInput, INPUT);

  // Set up pull-up resistors on inputs

  digitalWrite(rotAPin, HIGH);

  digitalWrite(rotBPin, HIGH);

  digitalWrite(pushPin, HIGH);

  digitalWrite(brightnessPin, HIGH);

  digitalWrite(gnd, LOW);

  digitalWrite(vcc, HIGH);

  digitalWrite(tunespeedLED, LOW);

  digitalWrite(PTTInput, LOW);

  // Set up interrupt pins

  attachInterrupt(digitalPinToInterrupt(rotAPin), ISRrotAChange, CHANGE);

  attachInterrupt(digitalPinToInterrupt(rotBPin), ISRrotBChange, CHANGE);

  // Initialize the display

  display.setBrightness(Brightness, true);

  UpdateDisplay();

  delay(1000);

  // Initialize the DDS

  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);

  si5351.set_correction(29100, SI5351_PLL_INPUT_XO);      // Set to specific Si5351 calibration number

  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);

  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_2MA);

  si5351.drive_strength(SI5351_CLK2, SI5351_DRIVE_2MA);

  SendFrequency();

}

void loop()

{

  LowPower.idle(SLEEP_60MS, ADC_OFF, TIMER2_OFF, TIMER1_OFF, TIMER0_ON, SPI_OFF, USART0_OFF, TWI_OFF);

  currentmode = digitalRead(PTTInput);

  if (currentmode != oldmode)

  {

    SendFrequency();

    oldmode = currentmode;

  }

  currentfreq = getfreq();                // Interrupt safe method to get the current frequency

  if (currentfreq != oldfreq)

  {

    UpdateDisplay();

    SendFrequency();

    oldfreq = currentfreq;

  }

  if (digitalRead(brightnessPin) == LOW)

  {

    Brightness--;

    display.setBrightness(Brightness, true);

    if (Brightness == -1)

    {

      display.setBrightness(0, false);

      digitalWrite(tunespeedLED, LOW);

      batterySave = 1;

    }

    if (Brightness == -2)

    {

      Brightness = 3;

      batterySave = 0;

    }

    UpdateDisplay();

    delay(500);

  }

  if ((radix == 100) && (batterySave == 0))

    digitalWrite(tunespeedLED, HIGH);

  if (radix == 1000)

    digitalWrite(tunespeedLED, LOW);

}

void wakeUp()

{

  // Just a handler for the sleep pin interrupt.

}

long getfreq()

{

  long temp_freq;

  cli();

  temp_freq = freq;

  sei();

  return temp_freq;

}

// Interrupt routines

void ISRrotAChange()

{

  if (digitalRead(rotAPin))

  {

    rotAval = 1;

    UpdateRot();

  }

  else

  {

    rotAval = 0;

    UpdateRot();

  }

}

void ISRrotBChange()

{

  if (digitalRead(rotBPin))

  {

    rotBval = 1;

    UpdateRot();

  }

  else

  {

    rotBval = 0;

    UpdateRot();

  }

}

void UpdateRot()

{

  switch (rotState)

  {

    case 0:                                         // Idle state, look for direction

      if (!rotBval)

        rotState = 1;                               // CW 1

      if (!rotAval)

        rotState = 11;                              // CCW 1

      break;

    case 1:                                         // CW, wait for A low while B is low

      if (!rotBval)

      {

        if (!rotAval)

        {

          // either increment radixindex or freq

          if (digitalRead(pushPin) == LOW)

          {

            if (radix == 1000)

              radix = 100;

            else if (radix == 100)

              radix = 1000;

          }

          else

          {

            freq = (freq + radix);

            if (freq > bandEnd)

              freq = bandEnd;

          }

          rotState = 2;                             // CW 2

        }

      }

      else if (rotAval)

        rotState = 0;                               // It was just a glitch on B, go back to start

      break;

    case 2:                                         // CW, wait for B high

      if (rotBval)

        rotState = 3;                               // CW 3

      break;

    case 3:                                         // CW, wait for A high

      if (rotAval)

        rotState = 0;                               // back to idle (detent) state

      break;

    case 11:                                        // CCW, wait for B low while A is low

      if (!rotAval)

      {

        if (!rotBval)

        {

          // either decrement radixindex or freq

          if (digitalRead(pushPin) == LOW)

          {

            if (radix == 100)

              radix = 1000;

            else if (radix == 1000)

              radix = 100;

          }

          else

          {

            freq = (freq - radix);

            if (freq < bandStart)

              freq = bandStart;

          }

          rotState = 12;                            // CCW 2

        }

      }

      else if (rotBval)

        rotState = 0;                             // It was just a glitch on A, go back to start

      break;

    case 12:                                        // CCW, wait for A high

      if (rotAval)

        rotState = 13;                              // CCW 3

      break;

    case 13:                                        // CCW, wait for B high

      if (rotBval)

        rotState = 0;                               // back to idle (detent) state

      break;

  }

}

void UpdateDisplay()

{

  TensMHz = freq / 10000000;                                // TensMHz = 12345678 / 10000000 = 1

  remainder = freq - (TensMHz * 10000000);                  // remainder = 12345678 - 10000000 = 2345678

  OnesMHz = remainder / 1000000;                            // OnesMhz = 2345678 / 1000000 = 2

  remainder = remainder - (OnesMHz * 1000000);              // remainder = 2345678 - (2 * 1000000) = 345678

  HundredskHz = remainder / 100000;                         // HundredskHz = 345678 / 100000 = 3

  remainder = remainder - (HundredskHz * 100000);           // remainder = 345678 - (3 * 100000) = 45678

  TenskHz = remainder / 10000;                              // TenskHz = 45678 / 10000 = 4

  remainder = remainder - (TenskHz * 10000);                // remainder = 45678 - (4 * 10000) = 5678

  OneskHz = remainder / 1000;                               // OneskHz = 5678 / 1000 = 5

  remainder = remainder - (OneskHz * 1000);                 // remainder = 5678 - (5 * 1000) = 678

  HundredsHz = remainder / 100;                             // HundredsHz = 678 / 100 = 6

  remainder = remainder - (HundredsHz * 100);               // remainder = 678 - (6 * 100) = 78

  TensHz = remainder / 10;                                  // TensHz = 78 / 10 = 7

  remainder = remainder - (TensHz * 10);                    // remainder = 78 - (7 * 10) = 8

  OnesHz = remainder;                                       // OnesHz = 8

  display.showNumberDec(((1000 * HundredskHz) + ( 100 * TenskHz) + (10 * OneskHz) + HundredsHz), true);

}

void SendFrequency()

{

  if (currentmode == 1)             // Transmit

  {

    si5351.set_freq(((freq + BFO_freq) * 100ULL), SI5351_CLK2);

    si5351.set_freq((BFO_freq * 100ULL), SI5351_CLK0);

  }

  else                              // Receive

  {

    //si5351.set_freq(((BFO_freq - freq) * 100ULL), SI5351_CLK0);   // Low side injection

    si5351.set_freq(((BFO_freq + freq) * 100ULL), SI5351_CLK0);   // High side injection

    si5351.set_freq((BFO_freq * 100ULL), SI5351_CLK2);

  }

}