I don't see how? the Low pressure sodium lamp is very efficient??

Only when you compare bare lamp in diffusing test spheres. Yes, it wa enough for their balooned marketing, but not that much practical value given their size.

In their complete systems for the final task, they are not the most efficient anymore. HPS performs better for streetlights due to the higher efficiency of the beam control (about twice as much without any excessive size/cost/complications, when compared according to the minimum illumination level across the target area). At fraction cost.

LEDs could reach that even with white (of any tone from the commonly used range) light, but their reliability is everything but proven (I have doubts that will ever change - the persistent push for "lowest cost at any expense" will prevent that). But technically it is possible to make the lamps relible, that is just not any of the design goals from the marketing dept.

The only niche tgey are able to serve is the monochromatic illumination, be that for visibility in fogs, or filtering in astronomic observation equipment. And that is too small market to justify the production, when the only technical advantage in these niche areas over other technologies is efficacy (LEDs are able of monochromatic output at similar wavelengths, but are there less efficient).

Not effecient in the sense that it is limited in the color spectrum it provides.  Otherwise an awesome awesome light I love it. 

Sweden has pretty much not had any LPS lights for quite some time. I remember that around the time mercury lamps where forbidden in Europe, the swedish capital city Stockholm released a report on it's lighting and what needed to be done to meet their efficiency goals. Back then, in 2014/15 (might even be in 2013) only 1% of installations comprised of LPS. These are guaranteed to be gone now.

LPS had to go, yes it is efficient on paper, but there are so many cons - really bad lighting quality, very expensive light sources and generally large and bulky (therefore expensive) fixtures that restricts fixture design (why do you think they all pretty much look the same?) and light that does not work at all with our eyes during the night.

It just had to go, LED's, flourescents and metal halide have just surpassed LPS in too many aspects.

...and light that does not work at all with our eyes during the night.

It just had to go, LED's, flourescents and metal halide have just surpassed LPS in too many aspects.

What sort of SOX wattage did you use to enter the scotopic world? 1/4 watts? The wavelengths from the low-pressure sodium lamp, 589.0 and 589.6 nm, will always be in the photopic region where the peak sensitivity of our eyes is at 555 nm.

Broad sprectrum (white) lighting is totally unnecessary (some say dangerous) in many NIGHT time situations. The push for metal-halide lighting for docks annd loading platforms since the 1990s, for example, is a clue to where the motives of the lighting industry is placed. "Let us reap the bigest profit per job."

Very sad to hear...

Right now it is important to stock up on spare bulbs before the prices balloon!

The price is already there!!, 10 years ago you could get an 18watt SOX in the UK for just £11 wholesale, now prices START at £50 for the same lamp, and the later ones are total garbage!
I stopped using SOX in 2011 after a bad batch I bought for £116 kept going black within a year!

I stopped using SOX in 2011 after a bad batch I bought for £116 kept going black within a year!

So that we won't make the same mistake, exactly which lamps did you buy?

Osram branded Philips, made at Hamilton, batch N718
These:, The blackened one was within a years use, others followed suit!

Goodbye to the most wonderful light source ever invented, well that's what I think, anyway    I would love to have been able to vist the factory and seen first hand how these lamps were made 

At least many of us have been able to preserve some, they will never die in our eyes 

Production may have ended. But I have enough lamps to last me most if not all my life and intend on getting a few more just to secure that.

The foot of my driveway will one day be glowing monochromatic orange.


I need a streetlight for them though
... I have bulbs and gear but since these lamps are so long its hard to find a lantern to modify. And 55 watt lanterns on ebay are hard to find.

Production may have ended. But I have enough lamps to last me most if not all my life and intend on getting a few more just to secure that.

The foot of my driveway will one day be glowing monochromatic orange.


I need a streetlight for them though
... I have bulbs and gear but since these lamps are so long its hard to find a lantern to modify. And 55 watt lanterns on ebay are hard to find.

Use a t8 vapor proof fixture. I’m in the process of modding one now to accept up to 180w! Just need to figure out a side entry mount and a ballast box to mount to the back of it.

Use a t8 vapor proof fixture. I’m in the process of modding one now to accept up to 180w! Just need to figure out a side entry mount and a ballast box to mount to the back of it.

That's a good idea.. Where could I get a two foot version?

Here’s one

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F253800307866

Production may have ended. But I have enough lamps to last me most if not all my life and intend on getting a few more just to secure that.

The foot of my driveway will one day be glowing monochromatic orange.


I need a streetlight for them though
... I have bulbs and gear but since these lamps are so long its hard to find a lantern to modify. And 55 watt lanterns on ebay are hard to find.

Well said that man.!! 

Here’s one

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F253800307866

How well do you think the two foot single l as mp model would do? Any space for a ballast or would I have yo go with a double lamp fitting?