anchor.diff:  
       let private deriveAutoFrequency systemContext
                                       (projection : LegacyAcousticProjection)
  -                                    : Frequency = // Return proper type for AcousticSettings frequency
  +                                    : Frequency = // Return proper type for AcousticSettings raw frequency
   
           let window = deriveWindow systemContext projection
  -
  -        if window.Max > SonarConfig.systemTypeRangeMap.[systemContext.SystemType].UsableRange.LFCrossoverRange then
  +        let crossover =
  +            SonarConfig.systemTypeRangeMap.[systemContext.SystemType].UsableRange.LFCrossoverRange
  +
  +        if crossover < window.Max then
               Frequency.Low
           else
               Frequency.High
  
positive.code:         { projection with Frequency = frequency }
  
  
      //-------------------------------------------------------------------------
      // Top-level implementation of the functions necessary for mapping the project.
  
      let constrainProjection (systemContext: SystemContext) (projection: LegacyAcousticProjection) =
  
          failwith "nyi"
  
      let applyChange systemContext projection change : LegacyAcousticProjection =
  
  
negative.code: 
      let toSettings systemContext (projection: LegacyAcousticProjection) : AcousticSettings =
  
          let frequency =
              match projection.Frequency with
              | LowFrequency -> Frequency.Low
              | HighFrequency -> Frequency.High
              | AutoFrequency -> deriveAutoFrequency systemContext projection
  
          let struct (enableTransmit, enable150Volts) =
              match projection.Transmit with
              | Off ->        struct (false, false)
              | LowPower ->   struct (true,  false)
              | HighPower ->  struct (true,  true)
  
          failwith "nyi"
  