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Heatercathodeshort · 11th Nov 2019, 12:14 pm

That looks OK to me. An aged tube will show a very pale yellow/brown rectangle in the area the picture is formed due to the intense electron beam at 25kv on a 2 1/2" tube.

Burn marks due to circuit faults are small black dots or imperfections that magnify into large blemishes when seen on the receiver screen. Make sure the tube face is clean. Your marks look like they are just dirty smears.
At least you can use this one for test but do not fit a good tube until you are sure everything is operating correctly. John.

11th Nov 2019, 12:14 pm	#10
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Spotted - ID needed please - console TV.. Decca?? That looks OK to me. An aged tube will show a very pale yellow/brown rectangle in the area the picture is formed due to the intense electron beam at 25kv on a 2 1/2" tube. Burn marks due to circuit faults are small black dots or imperfections that magnify into large blemishes when seen on the receiver screen. Make sure the tube face is clean. Your marks look like they are just dirty smears. At least you can use this one for test but do not fit a good tube until you are sure everything is operating correctly. John.