08-02-2018, 08:53 AM
Hi.
Oddly enough I have only used one "X" type cap in an AC/DC set. The set in question nearly caused a house fire but lived to tell the tale.
It is a Luxuri Japanese micro valve set, no doubt intended for 110v areas but sold here with the addition of a 2.2uf cap dropper.
The radio was 100% original nothing had been changed as all caps were fine with no leakage currents and resistors were as marked.
A visit from David Boynes a few years ago brought out the set and it was playing away on the carpet, we adjourned into the shed with set on (volume was low) after an hour we came back in to a rather odd smell, yes the dropper cap had shorted but the set was still playing away. quickly it was disconnected and put in the kitchen sink, it was literally so hot, even the pile on the carpet was flattened.
A few days later I replaced the 2.2uf dropper cap and all was well, the valves were still fine as was the main smoother and all resistors were still OK with unchanged values, the only notable damage was the wax from the output transformer had long gone.
There was no room for a motor run cap so an "X" type was fitted. The radio is rarely used but it does get a very occasional airing, a 200ma fuse is fitted in the set now, normal mains consumption is 190ma so I'm sure if the cap shorted it would blow the fuse.
I think I'm correct in saying, motor run caps are more reliable in this application the ones I use are rated at 440v ac.
Oddly enough I have only used one "X" type cap in an AC/DC set. The set in question nearly caused a house fire but lived to tell the tale.
It is a Luxuri Japanese micro valve set, no doubt intended for 110v areas but sold here with the addition of a 2.2uf cap dropper.
The radio was 100% original nothing had been changed as all caps were fine with no leakage currents and resistors were as marked.
A visit from David Boynes a few years ago brought out the set and it was playing away on the carpet, we adjourned into the shed with set on (volume was low) after an hour we came back in to a rather odd smell, yes the dropper cap had shorted but the set was still playing away. quickly it was disconnected and put in the kitchen sink, it was literally so hot, even the pile on the carpet was flattened.
A few days later I replaced the 2.2uf dropper cap and all was well, the valves were still fine as was the main smoother and all resistors were still OK with unchanged values, the only notable damage was the wax from the output transformer had long gone.
There was no room for a motor run cap so an "X" type was fitted. The radio is rarely used but it does get a very occasional airing, a 200ma fuse is fitted in the set now, normal mains consumption is 190ma so I'm sure if the cap shorted it would blow the fuse.
I think I'm correct in saying, motor run caps are more reliable in this application the ones I use are rated at 440v ac.
