Even though I take great interest in doing upgrades, one of my least favorite things about upgrading locomotives to TMCC was finding a way to connect the antenna for TMCC connection, mostly for steam locomotives. Sometimes it is easy and the antenna can be hot glued to a plastic coal load in the tender (if applicable), but many times it's bit more tedious. Normally I do like to put the TMCC module in the locomotive where possible, which can be a bit of project depending on which engine.
To the point now, I have quite a few Lionel scale Hudsons and other high end steamers from the 80's and 90's that could benefit my use of them largely through TMCC upgrades. For locos like the 785 Hudson that have the cotter pin handrail mounting, I figured the handrails would serve as a good TMCC antenna provided the ends touching the boiler are insulated with heat shrink tubing.
For locos like the 5340 Hudson and T-1, that would be a bit more difficult. I figured the best decision would be to replace the handrail stanchions with the TMCC plastic handrail stanchions used for the TMCC Hudsons (or other TMCC counterpart):
It may be a downgrade from to replace the stanchions from metal to plastic, but aesthetically I doubt it'll make any difference. Would this make sense and work though? I figure it could work provided each end touching the boiler is, again, insulated.
I then feed the line through the hole in the stanchion and add a drop of super glue on the inside of the boiler to hold the fish line in place. It helps if you make the line coming out of the hitch 5-6 inches long to give yourself a little excess line to help pull through the stanchion holes. I also glue the two ends of the line together before pushing through the stanchion the stiffness helps push the line through the hole. I use the most convenient stanchion post to lead the antenna wire through. After leading the wire through the stanchion I will strip a half inch end and divide the strands into two bundles as evenly as I can and form a Y that wraps around the handrail. Now for soldering the stainless handrail. It's a piece a cake if you use the proper flux. "TINNERS FLUX" It is water thin Hydrochloric acid sold by NOKORODE PRODUCTS. The bottle I am showing is over 50 years old I bought it in my teens to scratch build a loco out of gallon cans. If soldering steel it is the thing to use but you will want to thoroughly clean when finished. The nice thing is how little it takes to solder the stainless handrails. I use a child's plastic pick-up stick slightly blunt one end and put a micro drop of acid right where I want the solder to adhere. I pull my antenna wire Y together and give it a slight twist then put a drop of solder on the tip of the iron and touch it to the spot. The acid will instantly vaporize and you will have a sound well wetted solder joint. I then use fingernail clippers and jewelers files to dress the solder joint. Some time I put some fine 1/16" heat shrink around the antenna wire as extra insulation inside the stanchion. I always store the Tinners flux inside a large cup to prevent the bottle from tipping over when open. This stuff is a bit dangerous. I also wear an oversize pair of #2 reading glasses as a bit of eye protection. One last point, the way the COW HITCH surrounds the handrail it forms it's own insulation and the rail never touches the stanchions.
