Rob wrote:
Does anyone have a link to a website for making a high power Z match? I
have made the 100 watt version with the toroid core and broadcast caps
which really works great. I thought maybe there might be a design out
there using heavier toroids for more wattage (500-1000 watts). Thanks
for any info, Rob

Assuming a constant Q or quality factor, the power handling of a toroid
is proportional to its surface area. Thus, to handle 10x more power,
you need 10x more surface area. A double thickness T400 toroid, 4
inches thick and 1.3 inches in diameter, should handle 600 watts,
assuming the T157 worked well at 100 watts. A stack of two T520
toroids should handle a kilowatt. In practice, the optimum Q moves
lower in frequency as the toroids get larger, which isn't necessarily a
problem, since hams tend to need more power on the lower HF bands.

Zack Lau W1VT