Quote:
Originally Posted by FERNSEH
The DC rating of a 300VAC class X capacitor will be much higher.
DFWB.
|
I would totally avoid any X class capacitor in any circuit where the uF value is important. Many continually lose capacitance over time.
Also if the job calls for a theoretical capacitor of around 500V, these days I simply fit a 1000V polyester or polypropylene part, because it allows for potential variation in manufacturing quality and tolerances and perhaps the more aggressive environmental conditions inside hot valve TV sets. This is also why I use the RS components silicone rubber insulated harsh environment wire in these sets.
Also modern capacitors are so much smaller, a 1000v part will probably be the same size as a 500V vintage capacitor. If space was an issue, obviously a 600V rated one would suffice. But in many ways it is better to know it will be definitely ok and you won't have to go back later to replace the same part.