Please don't get into the habit of hijacking threads (changing the subject).
300 amp Variac? That would be huge. Do you mean 300 watts?
With a 120 volt supply, the TS-520 draws about 280 watts on transmit and much less on receive.
BTW, the answers I've given you are available by searching the Internet. It's OK to ask questions, but some folks might get a little resistant to answering questions when the answers are readily available.