29-10-2019, 10:04 AM
First a point on terminology. The electrolytics are the reservoir and smoother capacitors. The mains filter cap (if any) is conencted directly across the mains input to reduce interference.
In the absence of a variac, a lamp limiter is the obvious way to power up an unknown set. I've not heard of using a UPS to do it. It's not a nice load for a UPS. An RCD in the mains feed is good protection for you, and make sure the chassis is conencted to mains neutral. An isolating transformer is only needed if you need to connect earthed testgear to the set.
Did you dry out the LOPT by passing DC through it for a day or 2? Highly recommended to drive off any residual damp in the windings. The winding resistance tells you almost nothing. Just that the winding isn't open circuit.
How did you clean the LOPT? The recommended method is a long soak in white spirit. Mechancial methods will probably damage the windings.
If the EHT rect heater is glowing (it's never very bright) then you should have good sparks.
In the absence of a variac, a lamp limiter is the obvious way to power up an unknown set. I've not heard of using a UPS to do it. It's not a nice load for a UPS. An RCD in the mains feed is good protection for you, and make sure the chassis is conencted to mains neutral. An isolating transformer is only needed if you need to connect earthed testgear to the set.
Did you dry out the LOPT by passing DC through it for a day or 2? Highly recommended to drive off any residual damp in the windings. The winding resistance tells you almost nothing. Just that the winding isn't open circuit.
How did you clean the LOPT? The recommended method is a long soak in white spirit. Mechancial methods will probably damage the windings.
If the EHT rect heater is glowing (it's never very bright) then you should have good sparks.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
