Calculating a neutral point

I've got a 200 foot uniform cross section series fed AM tower running 1,000 watts 1350khz that I want to mount an fm translator antenna on. I believe I could stand off the FM translator transmission line from the ground up the tower with insulators to a neutral point and then cross the line over to the tower and up to the fm antenna mounting point. Does anyone know if I'm on the right track here and if so how high up from the ground is that neutral point? Thanks for any help

You would need to come off the tower 90 degrees up from the base which is 182 feet at 1350 if my ciphering is correct. You could also use an isocoupler or isocoil and dispense with all the coax insulators.

I think you're talking about a 1/4 wave stub? You'll bond to the tower at the cross over and then tower bond up from there. Another option is an isocoupler
https://www.kintronic.com/shop/1-5-kw-fm-band-isocoupler/

The isolated quarter wave section was also referred to as a "bazooka section" back in the day. It can be done, but the isocoupler option will probably be cheaper and work just as well. You'll have to file for changes in the AM license regardless of what method you use.