Rewinding Transformer

[Gregory]

I have rewound a transformer .
The transformer chatters when I apply 240v.AC
At 120v AC It dos not chatter.
The transformer is a Isolation transformer for my CRO.240V to 240V
What causes the chattering and is there a direction the secondary winding has to be placed in relation to the primery winding in reguards to the direction the windings are wound.

 

[Nigel Goodwin]

I have rewound a transformer .
The transformer chatters when I apply 240v.AC
At 120v AC It dos not chatter.
The transformer is a Isolation transformer for my CRO.240V to 240V
What causes the chattering and is there a direction the secondary winding has to be placed in relation to the primery winding in reguards to the direction the windings are wound.

Doesn't your CRO already have a mains transformer inside it?, I would rather trust that than a home wound one!. If it's chattering?, presumably you have not wound it very well?, is it the primary or secondary you've wound?.

 

[Gregory]

It is the secondary that I have rewound.
When using the cro on a tv power supply I use a Isolation transformer