Here’s one service that’s thrilled with the DTV transition, which brought it back to life for its viewers. MHz Networks, owned by Commonwealth Public Broadcasting, carries international programming into 27 million households nationwide. MHz’s analog signal to its two channels went dark in September; it was the country’s first station to switch off. That caused empty static for many fans in the spot it used to occupy. Then, after the final June 12 transition and rescans by viewers … “We got calls from people all over saying, ‘You’re back!’ ” said CEO Frederick Thomas. Unfortunately the transition was bumpier for other stations: Current reported on the ongoing problems with channels disappearing from their usual spots after the transition — problems that in some states went all the way to the governor’s office and Congress.