Predicta vertical ghost line

[old_coot88]

Does the line change position (left/right) if you bump the horiz hold in both directions? Or does it stay in a fixed position regardless of the H hold setting?

[ShartZenith]

By adjusting the horizontal dial the line moves both directions almost off the screen. What does this mean?

[Don Lindsly]

That set does not have a horizontal drive or linearity control. The width control adjusts HOT screen voltage.

The "moveable" line is usually a result of an imbalance or over correction in the horizontal phase detector circuit. The resistors and caps in the feedback network and sync amp plate resistors are the first suspects. Aligning the horizontal oscillator sometimes helps. A model or chassis number would help for more specifics.

It may come and go depending on the signal source.

[ShartZenith]

Model H3410, chassis 10L43

[ctc17]

Davewm discovered this was do to poor quality modulators in cable and converter boxes.
The fix was a quality modulator like the BT Modulator. Adding the cap is just a bandade.

The crappy modulators also resulting in lots of buzzing with these old sets.

[old_coot88]

Originally Posted by ShartZenith

By adjusting the horizontal dial the line moves both directions almost off the screen. What does this mean?

It means the line is not originating in the H sweep section (ie., horiz osc or output) but somewhere in the video chain (or possibly in the phase detector).
You might try this.. Put a cap of say, .1 mf/600V from the cathode of the CRT to ground, which will kill the video signal. If the line remains, this will tell you it's not originating in the video chain.
(This is assuming video goes in the CRT via the cathode which is standard practice, rather than G1.)

[Phil Nelson]

For what it's worth, there was a long discussion of this issue on ARF. After a lot of checking & cogitation, I believe the punch line was that this is a characteristic of the design, at least somewhat, and you can reduce the line by adding a small capacitor, possibly at the risk of degrading the audio.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html