Here is a video provided by Brad Cheney, showing the first, modern mobile TV vans.
This was the project that I worked on back in the mid to late '60s at CBS Labs in Stamford, CT.
If you look closely, you will see the "Ground Fault" indicators in the van and on the external connector panel.
I designed these long before the current (no pun intended) solid-state versions were designed.
I was also responsible for the load balancing, intercom and RF remote head designs.
This was my first real "engineering" job, and I was very happy with the outcome!
Click on the arrow to start.
Give it a chance to get past the golf in the beginning, or move the slider!