Motorola roundie

[timmy]

Originally Posted by Yamamaya42

Weakness or imbalance in the horizontal output tubes may do it, this moto is an odd set with the pair of 6JM6s.

Well the tubes are new and I had the same line on the cbs Columbia and a slight adjustment of the horizontal frequency pot the line disappeared

[Yamamaya42]

Originally Posted by timmy

Well the tubes are new and I had the same line on the cbs Columbia and a slight adjustment of the horizontal frequency pot the line disappeared

My Stromberg Carlson X22 had the same sort of thing happen, faint white line when started, that would slowly fade after 20-30 min, caused by a weak/tired 6CU6 (11w max)
This went away after it was replaced with a slightly stronger 6GW6 (17.5W max)

Not sure if this is the same as your problem, but it may be similar symptom.