The Illinois Department of Transportation (IDOT) is giving notice of the intent to enter into a sole source contract with Westcode (Unipart) that will include a track circuit assistor (TCA) system for the purpose of signaling equipment interference testing on a test track. The Vendor will also provide a design proposal for a mounting frame for the TCA antenna and the Tuner unit that can be adapted and manufactured by the participating host railroad, Canadian National, for use on the test track for signaling equipment interference testing.