If it's a 1000pF capacitor used at 150W output to couple to a 50 Ohm antenna, at that power the capacitor would dissipate about 15W at 28 MHz (Xc = 5.7 Ohms).
One of those senior moments Steve? Power isn't dissipated in a reactance,
only in the resistive component.
Right, of course...I was assuming a very high DF, which is what I've found with Y5E/F/P/U/V ceramics and it "sounds" like that's what he has.
AVX rates DF of their Y5 types at 5% to 7.5% measured at 1 kHz, 100mVrms and 25C. At increased frequencies, voltages and temperatures, they're worse, in my experience.
I use a Boonton capacitance bridge, a variable frequency signal generator (to test at 1 MHz or 10 MHz), an external bias supply and a hair dryer...
Some of the ceramic disc caps I have (other than NP0 and other TC caps) measure very high DFs, way over 25%, sometimes 50%. I've had some fail, just testing them.
X7R's a lot better, but I don't think that's what he's using based on the description.