Hello friends,

We've been selling lumiline lamps on our eBay store after we acquired a few cases from an estate sale.

They have been selling but a few orders have complained and returned the bulbs due to a flickering. There is a vibration of the filament that causes a high frequency flashing light instead of a sustained light.

I wonder if they have gone bad over the years. We work so hard to find these rare bulbs, I'd hate to think they're no good.

Any information will help.

Your favorite eBay seller,
Dave

Are the “idoovad” seller on eBay? If so I’ve bought many lamps from you.  

That's me.  (Its a family business.)

Thanks for being a customer

Ive seen your listings, you have a lot of neat lamps would love to see you post them on your gallery, even if they are for sale on ebay.

I've also bought a number of bulb and ballasts from you also !    I wonder if the flickering could either be from loose filament supports or possibly something weird with the buyers line voltage .

 Other than developing an air leak , I don't see how they could have gone bad though maybe somebody else here could give you a better explanation . 

I think vibration is lacking the filament support for such long lamps.  The fiiament is trying to keep up with 60 HZ
 A/c cycle like a Bellafire lamp that being close to a magnetic source near by.

Ive seen your listings, you have a lot of neat lamps would love to see you post them on your gallery, even if they are for sale on ebay.

Moving forward if I see some cool bulbs I will definitely post here.




The buyer said after leaving them in for 5 minutes, they started burning normally. Love it when the problems resolve themselves. They originally turned them off as soon as they saw there was an issue.

Thanks everyone for your help. Also don't hesitate to reach out on eBay if you like some bulbs in our store, we can be flexible on the prices.

Dave

Hi Dave, nice to see you on here!  One day I hope to find time to upload some of the great lamps bought from you over the years :-)

This problem can be something that affects vacuum-type incandescent lamps with long filaments.  If the vacuum is not perfect there can be a small glow discharge forming around the filament, which is not usually bright enough to contribute to any light output but it seems that it can partially short-circuit some parts of the filament.  So what you see is the filament becoming dimmer and brighter as the discharge moves around.  After a few minutes the phosphorus getter coating inside the lamp may still be active enough to clean up the impurities, improve the vacuum, and resolve the problem.  It is a sign though that there may either be a tiny air leak in the lamps, or that they were not made cleanly enough during production - this means there is a risk that the lifetime may be shorter than usual.  If they are going to fail early, then after a few hours you will start to see either a greyish or smoky blue coating appear on the glass bulb.  However if they stay crystal clear then they should still perform well.

Hi Dave, nice to see you on here!  One day I hope to find time to upload some of the great lamps bought from you over the years :-)

This problem can be something that affects vacuum-type incandescent lamps with long filaments.  If the vacuum is not perfect there can be a small glow discharge forming around the filament, which is not usually bright enough to contribute to any light output but it seems that it can partially short-circuit some parts of the filament.  So what you see is the filament becoming dimmer and brighter as the discharge moves around.  After a few minutes the phosphorus getter coating inside the lamp may still be active enough to clean up the impurities, improve the vacuum, and resolve the problem.  It is a sign though that there may either be a tiny air leak in the lamps, or that they were not made cleanly enough during production - this means there is a risk that the lifetime may be shorter than usual.  If they are going to fail early, then after a few hours you will start to see either a greyish or smoky blue coating appear on the glass bulb.  However if they stay crystal clear then they should still perform well.

For a long filament lamp (and the filament being a very good uniform resistor....) the potential gradient along the tube, in close proximity to the filament, will be very uniform from end to end. If so, how does it even strike (with no high fields in specific spots), and if it happened to strike - what delimits it to a section of the filament and doesn't let it extend to form an end to end short ?

Thanks for all the replies everyone.

The bulbs were and are still crystal clear.

Just wanted to update everyone who replied. The customer told me that it eventually burned out after only a few days. Strange because we've sold many and this is the first complaint. I am just going to hope their fixture was malfunctioning. *sad refund noises*