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Old 19th Feb 2012, 11:15 am   #18
Heatercathodeshort
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Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
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Default Re: Pye VT2 EHT problems

Good work Matt. Interesting, if you have 1/2" of EHT on the rectifier anode and 400v on the first anode of the CRT the screen must light up. The EHT rectifier should be lit but remember the Ekco transformer uses a U25 with a 2v heater as apposed to the 6.3V EY51 in the VT2 You could add a few turns to the heater winding if you want to retain the EY51.
If it lights, you will have some EHT. The tube employs an ion trap and this might have become dislodged if you have cleaned the interior. If it is stuck fast, leave it alone for now. Check the grid and cathode voltages on the CRT base. A tripler will probably give way to high EHT. A doubler as used with the small screen Thorn 1500 chassis would be a better bet. Looking forward to the results. Regards, John.
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