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HV transformers: Difference between revisions
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In many classic scopes, the high voltage transformer that supplies the cathode, blanking, and anode voltages has a tendency to break down. | In many classic scopes, the '''high voltage transformer''' that supplies the cathode, blanking, and anode voltages has a tendency to break down. | ||
This is mostly because of aging of the potting material used for the high-voltage windings. | This is mostly because of aging of the potting material used for the high-voltage windings. | ||
When this happens, the transformer will run very hot because dielectric loss is too high. | When this happens, the transformer will run very hot because dielectric loss is too high. | ||
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This approach has been tested with success on a 556's HV transformer. | This approach has been tested with success on a 556's HV transformer. | ||
The same HV transformer, part number 120- | The same HV transformer, part number [[120-308]], is used in the [[543|543B]], [[544]], [[545|545B]], [[546]] and [[547]] . | ||
Chuck Harris, who frequents the Yahoo Tekscopes forum, has rebuilt several 120- | Chuck Harris, who frequents the Yahoo Tekscopes forum, has rebuilt several 120-308 transformers with good results. | ||
<gallery> | <gallery> | ||
KeepcoolHV.JPG | Alternative to replacement: cooling with a heat sink | KeepcoolHV.JPG | Alternative to replacement: cooling with a heat sink | ||
120-466-0x.JPG | Two | 120-466-0x.JPG | Two different HV transformers for [[561B]] & [[568]]. Brown potting ([[120-0466-00]]) is bad, clear potting ([[120-0466-01]]) is an improved variant to avoid the thermal problems. | ||
</gallery> | </gallery> | ||
[[Category:Repair issues]] | [[Category:Repair issues]] | ||
[[Category:Inductors and transformers]] | [[Category:Inductors and transformers]] | ||