Thread: Alba t655
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Old 6th Jul 2013, 11:13 am   #21
FERNSEH
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Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Alba t655

I hope this not going to be line output transformer failure. For the fault condition you have described I'd check or replace the PL81 first. Make sure that C47 which is the coupling capacitor between the line oscillator and the PL81 has been changed. Also check the values of the anode load resistors of the line oscillator valve, R60 and R61. R60 can go low in value and R61 high.
Check the boost capacitor C50, 0.1microfarads @1000v. Boost volts are high in this set, 630V. The PL81 screen feed resistor is known to fail. 1.5Kohm @ 2watts.
I hope the attached circuit diagram of the line timebase helps fault finding in this area of the set.

DFWB.
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