lack of horz sweep on color roundie
 

this ties into my old thread about a purple edge on my roundie, which was related to a lack of horz sweep (I think). I may have found something. while reviewing some other schematics I decided to put a 78pf cap across the horz windings (there is one internal to the yoke). This increased the sweep about 1/2 an inch, enough to get rid of the purple edge and make the horz centering less critical.

Now I dont know if the internal cap in the yoke has just opened up or what, but at least I am getting somewhere with more width.

My plan was to pull the yoke and just replace the existing cap and see if thaty does it.

oh a little history, all the bias/hv/drive waveforms check out, sweep tube is good, just a bit short on sweep. I could increase it by adj the horz tube bias 9there is a pot for it on this one) but that would shoot the HV up too high. when HV was adj to 25kv (brightness all down for min beam current) I would get the correct HOT current but just not enough sweep. I even went so far as to buy a new yoke, but never got around to installing it. The cap thing was just an experement based on looking at other schematics that had a provision for increasing the sweep, which involved a cap from the red lead of the horz sweep to ground. There was no such cap in this set or provision for it but I did see the 68pf internal cap across the horz sweep leads.