High Pressure Sodium Retrofit Bulbs (Finds of the Day 11-1-24)

[@digitricks]

That's the first time I've ever seen a retrofit HPS bulb and remember seeing just a couple of those in those at-the-time HUGE thick Grainger catalog books! So even right before you said it yourself, I thought Hey! You can try out that 250 watt DX mercury bulb in that Sentury floodlight! So DEFINITELY looking forward to a power-up video soon!💡💡 I know exactly what you mean. During the past and next week or so, my GM is having all the 175 watt metal halide showroom lights replaced with LED. Thus far nearly all of them say M57/H39 which means it can run metal halide AND mercury vapor bulbs of that same wattage which makes them all the more cool! I can't do anything with the huge housing but I have been actively rescuing the ballasts and capacitors from the dumpster just knowing I can put it to work somewhere. Soon I'll have way more than I'll ever use! So glad to be one of your subscribers and it makes me feel relieved to know there are still people out there with the same unique mentality and admiration for HID lights as I have!

[@Matthew-jn4jk]

Nice Westinghouse retrofit lamp! Date looks to be June, 1980

[@Ni5ei]

Love the retrofit HPS bulbs!

[@randacnam7321]

The 'penning' in the lamp designation for the Sentry light is in reference to these HPS retrofit lamps using a penning gas mix of 0.5% krypton/99.5% neon in order to lower the starting potential of the arc tube to where a mercury or metal halide ballast will start it. The tradeoff vs. the xenon fill in normal HPS lamps is lower efficiency due to penning gas being more thermally conductive leading to higher convective heat losses from the arc plasma and shorter lifetime. The neon and krypton atoms are much lighter than xenon and are thus accelerated to much higher velocities by the arc electric field, and since kinetic energy is related to the square of the velocity the electrodes get worn down by atomic impact faster. The glowbottle in the Iwasaki 220W lamp uses ballast inductive kick to start xenon fill HPS arc tubes from mercury and metal halide ballasts without needing easy starting penning gas fills or external superimposed ignitors. That lamp also uses an auxiliary starting antenna connected to one electrode in order to increase the electric field next to the other electrode and thus get a discharge to strike. This antenna is then moved away from the arc tube by a bimetal strip to reduce photoelectric sodium loss during operation. That ceramic plate is just to keep the lamp internals aligned so the bimetal strip can move the antenna properly.

[@jessecar96]

That Sentry light is so cool! I live near Freeport NY and have never heard of them before. That fixture is still on their website with the same bulb in it.

[@Parrot175]

I have no idea why I didn't notice their website before, you're right, they still have a photo of this flood light with the same bulb in it to this day! lol

[@TCG_Offical]

Video idea: take a look at the Sylvania 69043

[@misterhat5823]

Fan. Made in Hong Kong. It has to be fairly old.