I use a Lionel 5D tester. Used in conjunction with the test specifications found in the maintenance manual, I find it be a very useful tool. The transformer tests and the whistle relay tests and lamp tester are particularly useful. I rarely use the track portion of the tester. I find the roller stands more useful. In conjunction with the 5D tester I use a Fluke multimeter, a variable voltage DC lab power supply, test lamps, and clip leads. The Sun taster may be very similar to the 5D or 5F tester, but you would need to verify that.