9. Perhaps the most useful ACE-HF feature is the Circuit Analysis Screen Pop-Up menu. Right click anywhere on the screen to produce the pop-up. Then left click on the parameter you want to change. Current selections are marked. New predictions replace previous chart data in a few seconds, so it's easy to see the effect of a circuit change without returning to the Inputs Screen. You may choose a different chart type or service type from the left column. Selections from other columns will automatically re-run the predictions. For example, changing the SSN value will quickly show the effect of increased solar activity on your favorite band. The pop-up menu also permits a quick return to the Inputs Circuit or Area Coverage panel, or to the Main Screen, using the items in the right-hand column. Also, you can Hide the Main Chart or Open Bands Boxes and re-show them if you wish. This feature is useful when placing the receive site dot under the chart.