I have a Nagra T, just pulled it out of storage - I used to use this exact machine 30 years ago at a Post House here in town, and forgive my old age, and lack of a manual anymore, but I can't remember how to engage the heads after I thread the tape in. I remember you had to hold a button and apply tension, but for the life of me, I just can't remember. I used to do audio laybacks for film transfers, I could do them blindfolded. Now I just need a clue. Any help would be greatly appreciated. Thanks!