With my tuning unit for my 137 kHz LF amplifier the Ceramic feedthru fasteners are Brass 1/4 inch diemater - and are getting a little warm. Brass doesnt have the best low resistance compared with Copper etc.
 
With the Tx running last night full throttle (or close to it) the total loop current was approaching 65A causing the Bolt(s) to get quite warm.
 
The feedthrus are seen in the photo going thru the Rubbermaid at the back -  http://kl7uk.com/loop1500.jpg   (this is the original tuner - some of the components have changed for XPQ)
 
There is probably around 2Kv or more inplaces in the tuner and Im seriously considering running the antennae cable straight thru the tub wall using apporopiate weather proof grommets and using the plastic rubbermaid together with the wire insulation into the tuning components as the dilectric -  Im concerned about any heating up of components - but at this kind of current its more like designing a car alternator or battery system :-)
 
Any one any pointers or suggestions - Im trying to eliminate any nut bolt connection as Ohms arent wanted....
 
Laurence KL 1 X