Motorola TS-9B Horizontal Issue

[Penthode]

Originally Posted by Penthode View Post
In standard flyback circuit operation, the left hand deflection is through the damper tube. The right hand scan is through the horizontal output tube. There appears to be a high frequency oscillation occurring when the horizontal output tube conducts.

What does the waveform on the control grid of the horizontal output tube look like?

Originally Posted by StellarTV

Ah okay, I did think that it was the opposite of this. If this is the case, there are plenty of more components to suspect.

Because the ripples are on the right and because the ripples occur while the horizontal output tube is conducting, the HO tube may be modulating the sweep with the ripple on the control grid. If the ripple is being conducted through the grid, I would be very suspicious of the decoupling capacitor (electrolytic) feeding the horizontal oscillator.