wrote:

------------------------


you may have a magnetic field problem, not a circuit problem.
Try moving and re -orienting the power xformer relative to the CRT.
Often you can find a null point.
Otherwise you need mu metal shield or copper strap bucking turn.


** Mu-metal is effective against *weak* magnetic fields, like the earth's field. It is used to house small signal transformers, cover scope tube necks and the like.

However, a mains transformer has a *strong field* at close range so a copper band right round the winding and core is effective. The band ends must over lap and be soldered.

http://richardschurmann.com.au/Other...sformer-21.jpg

Don't be tempted to feed the band round the winding inside the core - then it becomes a *shorted turn* and the whole thing will get damn hot.


..... Phil