02-08-2023, 09:07 PM
(This post was last modified: 02-08-2023, 09:11 PM by Geordie McBoyne.)
"I've always thought this to be a most attractive console. Is it known what 12-inch tube was fitted?"
Hi Steve,
if the console model was released in 1938 the CRT is most likely to be the Mazda CRM121.
Good progress with the TS201 today. The 8mfd timebase HT supply reservoir capacitor was known to be faulty and has been replaced with a motor run capacitor. Taking your advice in an UKVRRR topic an RS Components component is employed. It fits neatly inside the old wet electrolytic can. The part number is: 377-8914.
Also requiring attention were the timebase valves heater cables. The perished insulation replaced with heat shrink sleeving.
After more pre switch-on checks a small picture appeared in the screen. After replacing many more components the picture almost fills the screen. Timebase HT voltage is 245V, this might be a bit on the low side.
Since the off-screen pictures were taken this afternoon the picture width has again become much reduced. One component that is often forgotten is the capacitor in the line linearity circuit. In the Ekco it's a 0.01mfd capacitor and will be of a high voltage pulse rating, say 800V.
Geordie McBoyne.
Hi Steve,
if the console model was released in 1938 the CRT is most likely to be the Mazda CRM121.
Good progress with the TS201 today. The 8mfd timebase HT supply reservoir capacitor was known to be faulty and has been replaced with a motor run capacitor. Taking your advice in an UKVRRR topic an RS Components component is employed. It fits neatly inside the old wet electrolytic can. The part number is: 377-8914.
Also requiring attention were the timebase valves heater cables. The perished insulation replaced with heat shrink sleeving.
After more pre switch-on checks a small picture appeared in the screen. After replacing many more components the picture almost fills the screen. Timebase HT voltage is 245V, this might be a bit on the low side.
Since the off-screen pictures were taken this afternoon the picture width has again become much reduced. One component that is often forgotten is the capacitor in the line linearity circuit. In the Ekco it's a 0.01mfd capacitor and will be of a high voltage pulse rating, say 800V.
Geordie McBoyne.
