Need more help with TIG

I was talking to my neighbor last week about the jury rigged tig setup I'm using. He sez, 'I gotta tig thing I'm not using'. So, I take a look and it's a Lincoln Hi-Freq unit, and is now sitting on my bench, (borrowed, he won't sell it.) The manual sez there is a capacitor kit included with the Hi-Freq to put across the output of the welder to soak up high frequency voltage to keep it out of the transformer. It's gone. What type and value of cap should I put in there? Also when he wants this thing back, are there any plans available for a homebrew version? Tom