19-08-2017, 11:08 AM
That's better. The intermittent in the set was some dry joints on WW resistors in the PSU regulator. The PM5519 justs seems to be behaving itself now.
Plugged in all panels except LTB and EHT. As well as video at the CRT cathodes there's now sound and field scan looking OK.
Next step, line timebase. I have 2 of these, the original one to the set which looks like it's been got at, with a couple of parts missing and some scrappy soldering suggesting that the LOPTs have been removed at some point. The other board looks much better so I'll give it some power gently and see what happens. Won't be before tomorrow now.
I need to look at the 55V rail adjustment which is very touchy. The pot has too wide a range and is a bit scratchy despite a dose of Servisol. I may well add a resistor in series with the top of the pot and change the one in series with the bottom. The 73V unreg supply is rather high, around 85V. Mains voltage is close enough to 240V and the set is on the 240V tap. May well drop a bit when the LTB and EHT are loading the transformer fully.
Plugged in all panels except LTB and EHT. As well as video at the CRT cathodes there's now sound and field scan looking OK.
Next step, line timebase. I have 2 of these, the original one to the set which looks like it's been got at, with a couple of parts missing and some scrappy soldering suggesting that the LOPTs have been removed at some point. The other board looks much better so I'll give it some power gently and see what happens. Won't be before tomorrow now.
I need to look at the 55V rail adjustment which is very touchy. The pot has too wide a range and is a bit scratchy despite a dose of Servisol. I may well add a resistor in series with the top of the pot and change the one in series with the bottom. The 73V unreg supply is rather high, around 85V. Mains voltage is close enough to 240V and the set is on the 240V tap. May well drop a bit when the LTB and EHT are loading the transformer fully.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
