Checkbox checked not passing an actual value?

My code checks the value of 2x checkboxes to equal true/false depending on a radio field. I see the checkboxes being ticket on the web page.

However, once they are passed over a HTML POST form, they have no values and always equal false.

If I give the checkboxes a value "TRUE" then of course they have only that value.

What am I missing here?

    <script>      
      $(function() {
  var MAIN= $("input[type='radio']");
  var marketingPhone = $("input[type='checkbox'][name='marketingPhone']");
  var marketingRobo = $("input[type='checkbox'][name='marketingRobo']");


    MAIN.on('change', function()
        {
        if ($(this).val() == "TRUE")  {
          marketingPhone.prop('checked',true);
          marketingRobo.prop('checked',true);
        } else {
          marketingPhone.prop('checked',false);
          marketingRobo.prop('checked',false); 
        }

    });
});
  </script>

The fields are as follows:

        <input type="checkbox" name="marketingPhone" value=""/>
        <input type="checkbox" name="marketingRobo" value=""/>