Back in 1992, Liam Rudden and I spent a day interviewing and filming Jon Pertwee (the third doctor) while he visited Edinburgh to promote the VHS release of 'Doctor Who: The Pertwee Years.' In 1999 we recorded some tributes and memories from fans and colleague Richard Franklin (who played Mike Yates during Jon's tenure as the doctor). We added these tributes to the 1992 footage that shows Jon at work (and relaxing behind the scenes). After dusting off the old mini DV master tape we've popped our documentary - Reverse the Polarity - online for fans of Jon Pertwee (and classic Doctor Who) to enjoy.