E-UNIT-79, Thank you for that suggestion.
gunrunnerjohn, that's a good question. In the beginning it was to determine if the ZW was working or not, so I knew how to list it for sale. Then I became intrigued with how the whistle system worked, which lead to getting the diagram, and running more tests, which raised more questions about whether not the ZW was working in whistle more. The simulations were part of understanding how the whistle system worked. The information you provided helped me resolve the question of whether or not the ZW was working or not.