11-11-2016, 08:06 PM
Good progress today. A number of resistors associated with first two TRF amplifier stages were found to be well out of tolerance, replacing these parts improved matters, but only slightly. The MSP41 valve is a difficult one to find these days, however, I found an example which improved the signal handling so now thre is far less crushing of the active video at higher settings of the sensitivity control. There might be an issue with the final RF transformer L13 and 14. I understand this transformer is heavily damped by the the vision detector but this RF transformer cannot be peaked up whatsoever, well worthwhile investigating this area of the set.
Nevertheless, there is almost 15volts P - P video present at the output terminal. So now the CRT will be receiving 10 volts of video, that's an useful improvement but really the ideal figure should be 20 volts P - P.
Geordie McBoyne.
Nevertheless, there is almost 15volts P - P video present at the output terminal. So now the CRT will be receiving 10 volts of video, that's an useful improvement but really the ideal figure should be 20 volts P - P.
Geordie McBoyne.
