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Old 25th May 2022, 4:16 pm   #2
Ted Kendall
Dekatron
 
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
Posts: 3,657
Default Re: Head changes on a Revox PR99

Wrap, height and face tilt are the points you need to watch. Replacement original heads would usually be fine without adjustment of height or tilt, because the manufacturing tolerances were held to tight limits. The head is retained by a single screw, so wrap has to be correctly adjusted - the gap should lie in the centre of the wrap.

To check these points, apply some felt tip pen or engineer's blue to the head face and run a (dispensable) tape. You should see a rectangular contact patch with the gap in the middle. If there is, clean up, adjust azimuth, job done. If the patch spreads at top or bottom, the face tilt is out. Be careful with adjustment so that you don't lose track of where you are and can't return to the original state. If the height is out, the patch may miss parts of the head core, but this is unlikely.
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