The installation is for HO-Scale Broadway Limited Blue Line GE C30-7. It uses TCS DP2X or T1P-MH or MC2P-MH decoder and was performed by a TCS Customer
There are several good options for installing a TCS decoder in this Blue Line GE C30-7 locomotive. The DP2X is the most simple and straight forward, it plugs directly into the 8 pin NMRA socket supplied with the locomotive. The TCS extension plug must be used with the DP2X decoder for this installation. The extension plug is sold separately from the decoder. If your dealer does not have an extension plug in stock call TCS directly and we will mail one to you right away. The T1 decoder with a medium length harness, the MC2 decoder with a medium length harness, or a M1 decoder with a medium length harness will also work just fine. Below are pictures of some of the options.
This is another classic installation for the DP2X! DP2X with extension socket. DP2X stands for "Direct Plug-two function- X series lighting effects".
Photo below shows T1 decoder with medium length harness. A T1 decoder ordered together with a medium harness is part number T1P-MH.
Photo below shows MC2 with a medium length harness, part number MC2P-MH.