Photo Gallery

GE NA-1 Warming Up

This is the warming-up sequence of my NA-1 lamp. Looking at other photos, usually when they first strike they show only an argon purple color, and then slowly turn sodium yellow. This has not been the case for my lamp. I assume this is because of it's age, as it somtimes take 10 seconds or more to strike, probably from cathode wear. By that time the hot filament has probably evaporated some sodium into the bulb already.

As described before, once it is warmed up it is difficult to see the electrode structures inside due to the opaque sodium plasma. The lamp emits a very nice glow that is pretty relaxing, I could look at it for ages, though the rated lifespan of only 500 hours discourages that.

I have put two pieces of float glass agaisnt each other in the light from this to see the interference patterns which was quite cool. I might try and set up Young's slits to see that as well. And of course I have seen the effects of the monochromatic light on colored objects. This is my only LPS light source and I am glad it is something this special!
Keywords: Lamps

GE NA-1 Warming Up


This is the warming-up sequence of my NA-1 lamp. Looking at other photos, usually when they first strike they show only an argon purple color, and then slowly turn sodium yellow. This has not been the case for my lamp. I assume this is because of it's age, as it somtimes take 10 seconds or more to strike, probably from cathode wear. By that time the hot filament has probably evaporated some sodium into the bulb already.

As described before, once it is warmed up it is difficult to see the electrode structures inside due to the opaque sodium plasma. The lamp emits a very nice glow that is pretty relaxing, I could look at it for ages, though the rated lifespan of only 500 hours discourages that.

I have put two pieces of float glass agaisnt each other in the light from this to see the interference patterns which was quite cool. I might try and set up Young's slits to see that as well. And of course I have seen the effects of the monochromatic light on colored objects. This is my only LPS light source and I am glad it is something this special!

Screenshot_2026-05-02_194206.png Screenshot_2026-05-02_194726.png 1000036650.jpg Philips_126564.jpg WL-H33GL-T400-DX-N2-1.jpg
Lamp/Fixture Information
Manufacturer:GE
Lamp
Lamp Type:LPS
Filament/Radiator Type:Glazed borosilicate
Base:UX4
Service Life:500hr
Burning Position:BD
Fixture
Fixture Type:George W. Gates SLA-5C
Ballast Type:Leak transformer
Electrical
Wattage:28
Voltage:6.5
Current:4
File information
Filename:Screenshot_2026-05-02_194206.png
Album name:Drew / Sodium Lamps
Keywords:Lamps
Filesize:1327 KiB
Date added:03 May 2026
Dimensions:1769 x 876 pixels
Displayed:15 times
URL:https://trad-lighting.net/gallery/displayimage.php?pid=1242
Favourites:Add to Favourites

Comment 1 to 5 of 5
Page: 1

Sammi   [Sun 03 May 2026 at 13:00]
Very nice to see.! Cool
Max   [Mon 04 May 2026 at 07:31]
Awesome shot! It's the first time I see the run-up sequence of the NA-1, thanks for sharing that. I acquired this lamps nearly 25 years ago but never got around to lighting it due to the lack of proper gear.
Drew   [Mon 04 May 2026 at 14:26]
@Sammi
Thanks!

@Max
Just need two filament transformers with 1.5V @ 2.5A and a ~4A current limited source. If I were in your situation I would just wrap two 1.5V secondaries on a random transformer and use any 400W ballast on a variac for the main supply. Though of course any non-OEM setup has risks and you seem to have a lot more self-control than I do lol Laughing. Breaking one of those lamps would be nauseatingly unfortunate! Cool that you found one of these
Max   [Tue 05 May 2026 at 06:56]
Thanks for the tip, I'll definitely try that. I have to find a way to insulate the lamp properly so it can run up to its nominal temperature.
Drew   [Tue 05 May 2026 at 12:48]
Ahh right, no dewar jacket. I have seen others operate these without dewar jackets and they seem to work decently (probably not as bright of course), I don't think it will damage the lamp but I don't know and haven't tried it myself. Maybe a simple glass jar or globe placed over it would do, just to limit the airflow a little bit. If you do give it a try I would love to hear the results!

Comment 1 to 5 of 5
Page: 1