How has it worked out for you?
Your Procaster only goes 50-100 ft?
From a thread on Part15us about ten years ago...
"After visiting the Isotron website, this design for AM appears to be essentially a base-loaded, linear radiator having additional structures on each end, which can add a small amount to the radiation resistance, and reduce its capacitive reactance. The lower reactance could mean that the resistance of the loading coil could be a bit lower.
But this configuration has no effective r-f ground plane to work against unless that is provided by a conductor leading to one. The website page for the AM version recommends installing it on a 'metal mast,' which of course could provide the path to an r-f ground in/at the earth, as well as add to the effective radiating length of the Isotron antenna system.
The site also says it should be mounted 'as high as possible' for best performance. That is a strong indicator that the better performance comes not from radiation off the Isotron alone, but also from the metal mast that is supporting the Isotron above the earth."
I have experience for Isotrons in the amateur radio bands. The ones 20 meters and above (14 Mhz and up ) are a different design than the ones 40 meters and down ( 7 mhz and down ). The higher frequencies work well but the whole trick is how they are mounted and how the coax is feeding it. The reality with these things is that they must be mounted on a metal pole which is also the ground. At high frequencies (HF) having maybe a 10 ft pole can work ok. I had one for 40 meters ( 7 Mhz ) on a 6 foot pole and it did not work at all, so I gave up using any of the ones for lower frequencies. I do not recomment an Isotron for frequencies lower than 7 Mhz, it isn't going to be better than a loaded vertical.