71   General / General Discussion / Re: Questions about the modern use of quartz in lamps  on: February 01, 2026, 10:42:16 AM 
Started by Multisubject - Last post by James
Over the past decades there were many, many attempts to make quartz metal halide arc tubes from UV-stop quartz.  It does not work.

Firstly, the additives cause the softening temperature to be reduced.  Arc tube loading has to be reduced to avoid premature failure, and that causes a decrease of the halide vapour pressures and inferior performance.
Secondly, the cerium-titanium and/or aluminium ions in the UV-stop quartz make it more susceptible to halide corrosion, so again reduced life.

Regarding the LED Filament G9 type lamps, quartz is required to prevent overheating of the silicone LED during sealing.  That might sound counter-intuitive, since quartz has a much higher softening temperature than other glass types.    But speed is of the essence here.  With judicious use of liquid nitrogen coolants, quartz can be raised to its softening temperature, pinch-sealed, and cooled back down faster than normal glasses where prolonged annealing periods are required to remove stresses caused by the glassworking operation.  It is really challenging with soft and hard glasses to cool them fast enough without cracking, and during that time there is greater heat flux from the glass to the LED inside, which can cause degradation of the silicone and thermal expansion related damage to the silver plated gold bonding wires of the LED chips.
 72   General / General Discussion / Re: Google Street View Finds  on: February 01, 2026, 09:39:37 AM 
Started by LightsoftheWest - Last post by Cole D.
Some GE cobras on four arm poles at Stingray Chevrolet of Bartow Fl

https://maps.app.goo.gl/6TZ6kp9LwYdvfPpg6

https://maps.app.goo.gl/qrqADPvrY8FGt21HA


 73   Advertisements / Wanted / Ael 327 Or other High Wattage Streetlight  on: January 31, 2026, 11:34:15 PM 
Started by stillaintjeff24 - Last post by stillaintjeff24
If anyone had a preferably 1000 watt Cobrahead they didn’t want, let me know. I have been looking for a high wattage streetlight for a while. Even if it isn’t 1000 watts, if it is a large er streetlight, that’s ok.
 74   General / Off-Topic / Re: Severe weather never sleeps!  on: January 31, 2026, 09:51:06 PM 
Started by lightinglover8902 - Last post by Baked bagel 11
Most of AUS is pretty nice in winter, I'm in a colder area, where -7°c is normal at night I winter, but we never see snow. Maybe sleet once a year, and it's not remotely impressive! There are some places not too far from me in the mountains where it snows, such as in Thredbo. Not as impressive as the US though!
 75   General / Off-Topic / Re: Severe weather never sleeps!  on: January 31, 2026, 09:46:05 PM 
Started by lightinglover8902 - Last post by suzukir122
Does Israel and Australia ever see winter conditions like the U.S? I've been wondering this. Over here we're about to get back down to the negatives
in Fahrenheit. lol
 76   Lamps / Modern / Re: L.E.D Technology  on: January 31, 2026, 03:12:26 PM 
Started by Nineaclock - Last post by Lcubed3
Yes, they are definitely the future as far as I can see. The main thing about them is that they are so good and so efficient that lawmakers seem to feel the need to ban everything else.

Right now there is some legislation going through that will ban 99% of LED lamps currently on the market, as well as all fluorescent tubes. AFAIK HIDs are still exempted though.
 77   General / Off-Topic / Re: Severe weather never sleeps!  on: January 31, 2026, 02:16:23 PM 
Started by lightinglover8902 - Last post by Baked bagel 11
We're having a heatwave here, it got up to 44°c here last week, usually January just gets to 40 or so.
 78   General / Off-Topic / Re: Severe weather never sleeps!  on: January 31, 2026, 11:05:21 AM 
Started by lightinglover8902 - Last post by dor123
We will have tomorrow a heat wave here in Israel.
 79   Lamps / Modern / Re: GE "trimline" 4ft T8 3500k  on: January 31, 2026, 07:23:08 AM 
Started by RyanF40T12 - Last post by rapidstart_12
@RyanF40T12 - Deluxe Specification Series. Just GE’s brand name for triphosphor. SP for halophosphate/triphosphor blend and SPX for pure triphosphor.
 80   Advertisements / Wanted / Re: ballast for 90w sox?  on: January 31, 2026, 03:06:31 AM 
Started by Myrsky27 - Last post by Myrsky27
I’m from Finland. It’s incredibly Cheap
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