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Old 8th Mar 2018, 11:35 am   #25
Keith
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Join Date: Jan 2003
Location: Tewkesbury, Gloucestershire, UK.
Posts: 693
Default Re: Bush TV22 restoration

Having now managed to produce some 405 line video from an an old PC (albeit without interlace at present) I'm now able to proceed with the TV22. I'm getting a reasonably bright picture, having adjusted the centring and ion trap magnets but am getting a lot of line tearing/breakup. Looking at the anode of the sync separator I can see random fast noise spikes which I'm assuming are the culprits. If I move the scope probe to the other side of the differentiating capacitor (Trader sheet C26) the problem is considerably reduced, presumably due to the probe capacitance. The noise does not correlate with anything and seems to vary with time/temp. I'm wondering if it might be pickup of corona (not visible) from the LOPT which I haven't yet recoated. Anyone come across this before?
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