I'm on here all the time complaining about line voltage...to review, I live on a farm at the literal end of a rural above-ground line and I get 1) consistent 125 to 126 VAC line voltage and 2) the impact of every "event" that may occur on the line before it hits my house -- lightning strikes, downed lines, blown transformers, etc. After trashing out my Citation II twice and revamping my Dynas I finally talked a friend of mine out of one of his Variacs to use on the newly-repaired ($700 later) Citation, set at about 119 volts. I realize this will vary depending on my line voltage but it always seems to be in that high range and I figure 119 is a safe compromise...could go as low as 117 and as high as 120 maybe?
I see Variacs on Amazon etc. that go for about $100-$120 that will handle my load....I guess you have to get a little higher rating with these things depending on the pull there are some 3 or 4 amp units that are less expensive but I guess we need at least 6 and maybe 10 amps with these rigs, especially the H-K. The Brown Box looks convenient and small but it is over $300. Also something very comforting and traditional about an old, heavy wound Variac.