I'm getting bias readings 7ma apart for the tubes in my 70's 65 212 (with PI). This happens no matter if I use a pair of 6CA7's or EL34's. When just warming up the reading is 1 ma apart, but after 20 mins or so it reads as described. I've chosen 17 and 24 as a 'balance' for now, as the correct setting is around 22ma according to the forum. The tubes and amp sounds great, no problem there.
I'm using a meter I bought on ebay that sits between the tube and the socket and shows ma per tube. Handy.
Is this normal? It came this way when I bought it.