12-02-2010, 03:38 PM
If I recall right, my radio buddy and paid repairman has said that the 78 and 6D6 are indeed interchangable. Not sure if one is better than the other or not. I think the 6D6 is just a more 'modern' replacement that happened in the time right before octals came into being. Now I am curious as well.
No matter where you go, there you are.