I would really like to have a SON Deluxe/Comfort. I know a webshop where i can still buy a Son-T Comfort (high pressure sodium but with a CRI of 60!) for about 40 euro. However, this is an 150w lamp and that's just way too much to actually use indoors.

Does anyone know if there are 70w HPS lamps available from EU shops or sellers, with improved CRI? Currently i only have a 70w electronic driver for HPS. I also have 50/80w mercury vapor ballasts that can run HPS lamps with built in ignitor, of the right power rating.

I have contemplated getting some SDW-Ts but i would prefer a more conventional HPS lamp.

Hmmm, I could be wrong here, but I don’t ever recall a 70 watt deluxe HPS lamp ever being made?   

Yeah, that's the big question - do they exist in 50 or 70w?
AFAIK the japanese brands had some. But those are virtually nonexistant here.

These do exist in Europe, sure. In the form of SDW

I bet that because of basic square/cube law, low power white SON lamps are even more sensitive to power variations. Just a couple of watts off means different color, also the color drifts heavily on aging. So running them on a conventional ballast is possible, but not practical.

What is your problem with SDW-T/TG? These are cute, do not emit UV and never explode. So you can adapt them to any luminaire you wish, with a little attention to a reflector used, if any.

The issue is that i can only find affordable complete large SDW-T luminaires, which the seller on the other side of the country doesn't want to ship.
They're too large to strap to my motorcycle, and going by train and bus is a hassle with a large high bay lamp (also will cost me 20-25 euro single way or something like it). I've done it before with similarly sized PA speakers but i wanna avoid those kinds of adventures if i can...

The SDW drivers themselves at commercial shops are very expensive at at least 100 euro. So that's why i am looking for a 70w lamp that'll run on a standard driver. I also like it when it still looks like a SON lamp, the SDW's are probably so good that you can barely tell they're sodium lamps.

These high-bay luminaires are easy to disassemble, and prismatic diffuser alone is plastic and very lightweight, so the body goes to backpack and the diffuser is easy to carry in the hands.

Also, as I have posted, these guys in Germany supposedly sell electronic SDW ballasts for a very reasonable 14EUR https://www.breitengrad-null.de/produkt/philips-hid-pv-c-100-s-sdw-tg-mini-evg-100-watt-natrium-vorschaltgeraet-lampe/?v=6bf791021335

and some SDW-TG lamps too.

May be you can ask @VPL member in Finland, he seems to have inherited a ton of SDWs and ballasts.

Btw I have to pay around $100 for this luminaire, https://www.lighting-gallery.net/gallery/displayimage.php?pos=-234302 but it was NOS and in a rare 50W rating. And of course I wanted it direly

Oh, 100w SDW-T bulbs are easy and cost like 25 euro from private sellers here. Together with that german ballast it's a more realistic option

In the mid 1990s Osram GmbH offered NAV-E DE LUXE 35W and 70W lamps. They also came a globe versions. However I haven’t seen any in real life. Only in catalogue and technical leaflet.

Update: the trade company that sells those AEG high bay lights with SDW-T 100s, was prepared to ship me one, just without the big refractor. So i'll soon have the drive electronics for an SDW-t

Good luck, though I personally would regret not getting one of these prismatic reflectors/refractors, as these are rather cool looking in real, and add SDW lamp a lot of warm charm!

In the USA GE and Philips both made 70W Deluxe HPS lamps, but even those are quite rare.

If you only need the DX spectrum and not SDW, the easiest way might be to take eg an SDW-T 100W and run it on a lower power magnetic ballast or a dimmable metal halide electronic ballast.  That would cause the vapour pressure to decrease and rather closely replicate the DX spectrum.  Since you see to be rather good at spectroscopy, you could reduce power gradually until the sodium d-line drops to the same width as a DX lamp.

The opposite of taking a standard SON lamp and overdriving it is also possible, but the spectrum would appear slightly greener than a real DX since overloaded sodium lamps do not follow the blackbody locus when dimmed.  The DX lamps contain less mercury to brings their colour point back to the BBL.  SDW lamps have the necessarily high amalgam ratio to limit that effect.  It would still not be a perfect DX spectrum, but should be very close.

I wanted the 70w Deluxe versions for the ease of use (i already have a nice 70w Philips electronic driver), and because the amount of light is still somewhat doable indoors. Of course it's still a lot. But the 150w SON Deluxe i can find online, that would just be way too bright.
It's also because i like to see how good/bad the 'better' alternative to common SON lamps is. Why don't we see more of them? Were they that much more expensive, less efficient, or something else? The Deluxe mercury vapor lamps are really good in my opinion and even outdoors i feel that it would've made streets feel more friendy. I'm happily using my little 50w HPL-Deluxe, which has a very sufficient color rendering for domestic use. It's much nicer than a 640 fluorescent, for instance. Subjective of course, but still.

The SDW-T is neat because it marks the end of the line for sodium vapor lamps. I am really excited to see what kind of light it produces, and how it compares to warm white CDM-Ts or something.

White SONs have a nice unique warm color that oversaturates yellows, greens and reds in a pleasing way and high CRI, amount of deep red is just ridiculous, but are downgrade from common SON in almost all other ways. They are expensive, life is short and light output drops to about 1/2 of SON of the same power. And of course they need a complex stabilized ballast with a special voltage-current curve.

Looking at white SON running up is kinda fascinating. They sure start and stay for quite long in SOX monochromatic yellow, then gradually turn SON orange, and suddenly get that strange 'brownish' color. Brown is of course a wrong term for radiated light) but I like to call it that way...

Also all Philips SDW lamps flicker for unusually long time when started. I attribute that to simple rod electrode construction, without extra starting aid coils typical for almost all other HID lamps. So it takes a long time to heat the massive rods and do glow-to-arc transition. Wonder if heavy sputtering occurs at that time.


 

We just recently decided to maintain further our SDW-T 50W street lights on our promenade. Just ordered a bunch or spare bulbs for them. I still have plenty of gear/ controllers and sockets in stock and their light is unique so why not keep them? 

At home I‘m using some SDW-T 35W bulbs from 1986.