The Family DuMont

[kramden66]

if your still having line issues and brightness issues I'd still say the crt needs to be checked or a brightner added to see what you get , my ra-109 has a weak crt and will function without a brightener but you have to push the brightness to get a decent image and the retrace lines appear , with a brightener it takes less to push the brightness , the lines do not come in as easily and the whites are brighter along with blacks that are blacker , also you don't lose focus as easily either when brightener is added , since I have a crt tester I can see what the emissions are so this told me what to do, this it too why I added a resistor so the brightener isn't pushing its full voltage into the crt because at 7 volts emissions rise making it a decent picture , it does require a couple minutes of warm up before the focus and brightness come up but it is better to not over push the crt and have a warm up then to hit it with full voltage all the time.
so without a crt tester you don't know whats going on but you could try the brightener , it wont hurt , me and a friend have tried them on good crts in the past and saw no difference but when added to a weak crt a difference is seen , this is just a suggestion , I recently tried one on a color crt that tests good just to confirm a couple guesses from others that maybe an issue I had was the crt , it made no difference to its performance and was removed.