faint horizontal retrace lines on my Magnavox
 

I've finished restoring a Magnavox TV with chassis CT-214/218 variety. As I usually do, I'm feeding audio and video signals directly so I don't have to use a modulator or worry about RF/IF alignment. Audio is easy at the volume control. I usually feed video into the video amp tube after the detector. On this set, the video detector is actually a diode 1N34 that then feeds a 6SN7 tube before the signal goes to a 6AL5 for DC restoration and on to sweep/sync circuits. I have a good picture and sound from my DVD player, but I can faintly see what appear to be very fine retrace lines in the background of the picture, especially when there is no actual video present (like a blank screen in the movie or TV show. Is this due to my driving (over driving?) the video stage, or is this a different problem further downstream in the sync/sweep circuits? Are they the dreaded Barkhausen lines I've heard about but never experienced? Picture has great brightness and contrast, but may be just slightly overloaded from a too strong video signal being directly injected. I can get the picture just right with brightness and contrast controls (there is no AGC control). Any suggestions on making the retrace lines go away would be greatly appreciated.

Barkhausen appears as a ragged vertical line. Retrace lines are close to horizontal, but tilted some. Which do you see?

A picture is worth 1K words on what the set is actually doing.

Unless the tuner and or IF are fubar it's usually easier to use the tuner and an RF modulator/transmitter especially as your collection grows. Injection can cause problems (and should be saved for hopeless cases)...retrace lines aren't typically from overdriving the injection point (that usually results in a overly contrasty picture), but more common from under driving the injection point and cranking the gain (contrast) and brightness to compensate.

This is something you get a handle on with working RF when adjusting AGC in a set since AGC is basically a to set/regulate a signal level at the detector

Check the CRT voltages first. Also find where the blanking line come
in. Assuming its hoz blanking ( thin white lines across most of screen )
look for line tying the hoz with video. See if lines are there at LOW
brite & post a pix if you can.

good luck
Zeno:smoke:
LFOD !

Sounds like retrace lines to me.
They usually are not all that horizontal.
During vertical retrace the beam rapidly moves from the bottom of the screen
to the top while the horizontal sweep keeps running.
Early sets used the fact that the beam is moving rapidly to the top and therefore dimmed (because the brightness is spread out along the path) to not need a blanking circuit. That can only work to a certain degree.

It depends on how the video connection is made verses the original circuit but you might be upsetting the DC bias at the injection point, this could upset the video amplifier.