I just recently purchased a Williams F3 Diesel A-A set from Train World. The unit is a Baltimore and Ohio 20190. The train runs great but the horn sound is very weak and needs to be activated a couple times before it will sound. I am using a conventional transformer that does not have a bell button, it only has a horn button. Is this a problem that can be corrected and/or do I need an upgrade over my older transformer? Also, the color scheme is great and is there a B unit available to match the engines? The passenger cars are also B&O by Williams and the train would look even better with a B unit. And when was this unit manufactored, I do not see it on your website.......thanks for your anticipated help on these questions..................Bill Walter.