Osc. feedback ring
 

I changed the 1B3 tube on this old black and white tv and did not pay attention to the position of the spring that went around the lower part of the tube. Schematic says it is an osc. feedback ring. Does it matter exactly where it goes or is anywhere close to the bottom of the 1B3 OK?

According to the Motorola VT71 service manual, it should be 3/4" from the top of the base. I've also read that you can adjust it using an insulated probe (chopstick?) for maximum filament glow.