# Anyone else use an SOX security/area light?



## Zelandeth (Jul 22, 2004)

Just out of curiousity, does anyone here use an SOX light in their yard/driveway or anything?

I recently acquired (rescued just short of the skip) an old 35W LPS streetlight head (GEC model, date on the ballast/pfc cap reading 12 1969), and a well used, but functional 35W SOX tube, which I think dates from the early 90's. Has spent several years half submerged in water though, so all the writing's disappeared! - hence I can't be sure of that. Also have a 55W SOX tube, but no ballast to suit that. Ballast's a noisy beast of a thing, not to mention ridiculously heavy! Still it works...and for 35W...talk about bright! Haven't decided what to use it for (or just to keep it in here as a curiousity), would be interesting to see if anyone else has one of these in use.


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## jtr1962 (Jul 22, 2004)

While SOX was used quite heavily for street lighting in Europe, here in the US I think it would be virtually impossible to acquire one. High-pressure sodium (I think SON is the term) is used for streetlights, and 35W or 50w fixtures are sold for home outdoor lighting. Even so, SON is rapidly being replaced with metal halide. It's getting increasing hard to find a parking lot lit with SON these days, and I think in time the city will replace the SON streetlights with metal halide. There's no good reason to use SON anymore-metal halide comes very close in efficiency, gives a much nicer light, and actually appears _brighter_ watt for watt than SON (yes, I've seen side by side comparisons).

All that being said, I would love to get my hands on an SOX light in working order. I've heard everything appears just like an old black and white movie, except with a yellow tint.


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## brickbat (Jul 22, 2004)

I've been tinkering around with an 18W SOX lamp and have considered using it as an outdoor light - not for any practical reason, I just happen to like its golden color. And it's pretty unique here in the US - as already stated, SOX lamps never enjoyed much success here. 

I've not found a real SOX ballast and have been using a magnetic (as opposed to electronic) fluorescent instant start ballast with it and it works OK - The ballast delivers about 400 mA to the lamp, the lamp is rated at 350 mA, so its a pretty good match.

Tell me something, though. When I first power up a cold lamp, there is a bit of arcing at the cathodes - it's a blueish, pinkish flash of sorts that lasts for several seconds - then goes away as the lamp warms up. Does your lamp do this? I'm thinking it may be the ballast I'm using - can't be a good thing... I also tried an electronic ballast for instant start T8 lamps, but the cathode arcing was very pronounced, so I decided not to pursue that further, though I'd still like to find an electronic ballast for it.


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## The_LED_Museum (Jul 22, 2004)

The last time I saw a SOX fixture (in the 1970s I believe), it would start out as a very peculiar shade of red that I would term as "oxblood red", before slowly shifting to LPS yellow. So the warmup period was not only slow, but unusual to view.


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## brickbat (Jul 22, 2004)

Right - They have basically a neon red glow at turn on - makes sense, when they're cold, all the sodium is in solid form and the lamp has to heat up in order to vaporize it. There is a mixture of gases in them - mainly neon, I assume that give the pretty colors on warm up. It's also interesting in that the sodium vapor doesn't fill the entire tube at once - the warmest parts of the lamp glow orange and other areas are red for several minutes.


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## Chris M. (Jul 23, 2004)

I`ve got one on top of the wardrobe if that counts? Don`t use it that often for obvious reasons but it`s been up there for years next to a daylight fluorescent light I normally use. 55 watts, it`s essentially the complete gear tray from an Eleco "Golden Ray" GR551 streetlight head I rescued. The comparitively bulky body is stored safe in the attic but has a hole through one side of its yellowed perspex bowl - I presume it got shot with an airgun.


Just switched on:






Almost run up, just to prove it`s actually there:






Yes I know I`m odd but I don`t care any more.

/ubbthreads/images/graemlins/tongue.gif


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## The_LED_Museum (Jul 23, 2004)

[ QUOTE ]
*brickbat said:*
Right - They have basically a neon red glow at turn on... 

[/ QUOTE ]
I'm pretty certain the fill gas in low pressure sodium vapour blubs is predominantly neon; that's why they have an orangish red glow when first fired up.


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## Chris M. (Jul 23, 2004)

Anything and everything you ever wanted to know about Low Pressure Sodium lamps, asides where to get them from that is:

http://lamptech.co.uk/Documents/SO1%20Introduction.htm

You can buy them from wholesalers and lighting specialists here in the UK, as well as electronic suppliers like Radiospares, but avaliability worldwide is unknown. The UK used to love them, they were everywhere at one time. But I know in many countries worldwide, the monochromatic (nearly) orange colour wasn`t nearly as popular as mercury lamps. High pressure sodium (and to a lesser extant Halide) is rapidly taking over here, the lowly SOX lamp with its warm yellow glow is getting to be more of an endangered species. Which is a shame since those brighter and more "broadband" SON lamps pour so much more light in to the sky. When it goes cloudy at night, the world turns the colour of orangeade....

/ubbthreads/images/graemlins/rolleyes.gif


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## Zelandeth (Jul 23, 2004)

Hmm, that electrode arching thing, the old 55W lamp I have here seems to like sending bright pink, blue and wierd flashes for half a second or so. The 35W one doesn't seem so prone to it. 

The ballast I have here is an old magnetic one as well, curious now...wondering if it's actually a 55W ballast...as is seems a lot quieter running a 55W lamp than a 35W one...hmm...

One thing which is worth noting, is that there lamps must not (as I recall anyway) be operated with the cap at the lowest point.

I agree with Chris M, on the spectral characteristic there.

As a (very) amature astronomer, I've encountered the usual glow of streetlights getting in the way of things. Then the nearest villiage to us used all SOX lighting, this wasn't a problem. As there was just one wavelength there to worry about, and you could just filter that out. With flourescent and SON lighting there now, it's impossible to do that. And I need to drive another 25 miles in the wrong direction to escape that blasted whitish glow.

And colour rendering good or now, I like the SOX colour better than that of SON! Silly as it sounds, it's comforting in a way, as it's something that has always been there - and is now rapidly disappearing.


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## brickbat (Jul 23, 2004)

Just checked the ANSI spec, and both the 35W and 55W lamps have the same nominal operating current. Well - pretty close, anyway. So, to the extent that your ballast is a perfect current source, it should be able to operate either a 35 or 55 W lamp. 

The specs are as follows -- 35W

operating current 600 mA rms
operating voltage 60-80 V rms
nominal power 37 W
starting voltage <390 V rms

55W-
operating current 590 mA rms
operating voltage 98-120 V rms
nominal power 56 W
starting voltage <410 V rms

Of course a magnetic ballast isn't a perfect current source, but for the purposes of fiddling around with the lamp, it should be able to safely operate either.


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## Zelandeth (Jul 24, 2004)

Just went did a bit of research...in a highly technical manner. I.E. driving around the villiage where this fixture originated until I found a bunch of lamps of the same type...and checking what type of tube they had in. All 55W. Guess that's why it's quieter running the 55W tube. Seems to run them both fine, but it just doesn't sound happy running the 35W tube. Guessing the lower voltage is responsible for that.

Thanks for the info!

Hmm, looks as though I might have to look around for a new (or used) 55W lamp, as this one is in worse shape than I initially thought. Outer jacket is actually cracked (initially invisible under the grime), and the vacuum is gone (or at least has been severely compromised). Still works, but takes a long time to fully run up...and makes lots of scary pinging noises while doing so. At some point, the whole outer tube is going to part company with the base I reckon. Just hope I didn't cause this crack when I was cleaning it. Was as gentle as I could be!

Next challege: Identify and date the tubes. Yes, I know I've dragged my thread somewhat off topic...

35W. Osram, IR reflective film on the inner of the outer tube, imparts a greenish hue to reflections, whatever type that is (can't remember of the top of my head), no sodium retention dimples in the tube though, which puzzled me somewhat. Electrodes are the "beehive" shape. Cap is red porcelean. Will get a photo of it tomorrow (on the laptop just now, lacking the software to upload to my site). Sodium retention seems to be handled by a wider band on each side of the U-bend, clever design, and seems to work too. Sodium in this one's all over the place - because it decided to start rolling off across the desk while still warm. The 55W version is exactly the same, aside from the cap, which is brown rather than red. Only markings I can see are the maker (Osram), SOX and the wattages. No date codes or anything that I can see. 











Edit: 25 July 04. 21:34 GMT. There's the images I mentioned.


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## yuandrew (Jul 27, 2004)

I don't own any but there are LPS lights in So. Cal (including a few close to where I live). If you know 
Chino Hills and some of the surrounding areas, (Pomona, Chino, Diamond Bar) you should be familiar with the locations I know.
Anyway, the closest LPS lights are a pair of parking lot lamps at a day care center behind an old K-Mart store. There is another LPS "Wall Pack" on the side of the Target store in the Spectrum Marketplace. Diamond Ranch High School just off the 60 at Phillip's Ranch uses LPS for the parking lot but the road leading up to the school has HPS lights.The last location is my favorite at night as you can really see the difference in colors between the different types of lights (After stareing at both for a while, the HPS begins to look pinkish).

Other locations not close to me include San Diego (All the street lights are LPS near the Palomar Observatory, Silverwood Lake, and Long Beach near the Cal-State university (Streetlights have been recently converted to HPS but there are some LPS lights in an apartment parking lot across from a Ralph's supermarket).


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## yuandrew (Jul 27, 2004)

This is a picture I have from camping with my church up at Silverwood Lake. The lights on the side of this restroom are LPS. I didn't take a close up shot of the light fixture itself but I did get close to look at it. 
The light says "Norelco 120vac 18watt LPS ilumiare"


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