_http://www.ebay.com/itm/Heathkit-sb-220-new-tubes-/120944713514?pt=US_Ham_R adio_Amplifiers&hash=item1c28dddf2a_ (http://www.ebay.com/itm/Heathkit-sb-220-new-tubes-/120944713514?pt=US_Ham_Radio_Amplifiers&hash=item1c28dddf2a)