[Arran]

 I can't remember who made Philco test equipment but it was not Philco, they were made by one of the main test equipment companies like Precision or Supreme, chances are it's an emission tester, although a better emission tester. I also have a piece of Philco test equipment that I inherited, it's a variable frequency AC voltmeter made by a company called "Sierra". Near as I can tell they were often used by telephone companies for testing signal strength through their lines, I don't really know how useful it would be for radio and TV repair work.
Regards
Arran