Yep, it i the Recessed Bi Pin RDC connector

That's what it's called.
I have never seen a tube with that connector in person yet.

I can confirm we don't have SRS here. Also, in my experience, 8-foot T12 is much more common than 8-foot T8, but maybe that's just in this area.

I say my favorite is 15 watts, since the bulbs and fixtures are still easy to find. Re 8 footers. There's a mix of t8 and 12 here, with the largest t8 installation at an office max, which had the unique three lamp strips.

I say my favorite is 15 watts, since the bulbs and fixtures are still easy to find. Re 8 footers. There's a mix of t8 and 12 here, with the largest t8 installation at an office max, which had the unique three lamp strips.

There are almost no 3 lamp fixtures here, which is odd.

What's mildly interesting is the fact that the fixtures are most likely new, about 90s-00s vintage. Unless they scavenged and refurbished old fixtures from elsewhere, but that's highly unlikely.

I am not a huge flourescent lamp fan-the tubes I like are the T5 tubes used in outdoor enclosed fixtures that light the underside of the switchbay.These have been running for more than 5 years!they are a perfect 4K color.Next would be T8 type bulbs.I also like the colored flourescent bulbs.And Sylvania color flourescent Christmas lights.Would like to get some of these.A fellow that used to work at the transmitter collected them-should have asked to buy some from him.

As far as T12 goes.. It's a toss up between the 80s/90s GE F40T12 and 80s Sylvania F40T12.  (yes I love the Westinghouse black caps!) I love how the GEs would band the way they do and the long thick blackening when they go EoL. 
As for the T8s.. I liked the first gen Sylvania Octrons F32T8 but modern wise.. I am a big fan of the current GEs.  Unlike the Sylvania & Philips T8 tubes- GEs tend to warm up to operating temp very fast and are not super dim in the middle, and have a good life cycle in them.

Color purity:
Best 3000k- GE.  Sylvania.. is.. kind iffy- ok.. but could be better.  Philips tends to look too pinkish. 
Best 3500k- Sylvania or GE.  Philips again tends to look too pinkish to me. 
Best 4100k- Toss up between GE & Sylvania.  Philips cool white is.. well.. a bit off base. 

My favorite tube for lighting big places like warehouses would be any kind of T5. They have a higher operating temperature, so it makes it more suitable for warehouses where heat really rises.

I will never understand why they got rid of the 8 foot?, the 100watt 840s ran at a tidy 94 lm/W!
If thats not considered efficient I don`t know what is??

It is rather impractical length to handle. It started when the more common sizes were just about 50..60lm/W, so the 30% power savings made it worth to deal with such long tubes. But once even the most common (so cheaper) shorter size fluorescents became more efficient than this, it does not make any technical sense to mess up with so long and fragile tubes anymore.

And a lot of LED is actually less efficient!

A lot of LED's maybe, but just the older designs (I mean the LEDs alone). And saying that is the same like saying "A lot of fluorescents have way lower efficacy than even those lower efficient LED's". It just means nothing at all.
The real system efficacy of these is barely 85lm/W, while the LED's are already a year or so above the 100lm/W include the ballast.

Quote from: AngryHorse on August 20, 2016, 01:39:08 PM

I will never understand why they got rid of the 8 foot?, the 100watt 840s ran at a tidy 94 lm/W!
If thats not considered efficient I don`t know what is??

It is rather impractical length to handle. It started when the more common sizes were just about 50..60lm/W, so the 30% power savings made it worth to deal with such long tubes. But once even the most common (so cheaper) shorter size fluorescents became more efficient than this, it does not make any technical sense to mess up with so long and fragile tubes anymore.

Quote from: wattMaster on August 20, 2016, 01:39:58 PM

And a lot of LED is actually less efficient!

A lot of LED's maybe, but just the older designs (I mean the LEDs alone). And saying that is the same like saying "A lot of fluorescents have way lower efficacy than even those lower efficient LED's". It just means nothing at all.
The real system efficacy of these is barely 85lm/W, while the LED's are already a year or so above the 100lm/W include the ballast.

That's certainly true, and any dust building up on the tubes will just make it worse.
But don't forget that LED is tricky to manage for warehouses with hot ceilings, as you would need to reduce power to the LED to compensate for the higher heat, and that controlling would reduce efficiency, and make it more expensive as controllers cost a lot, and you would need more LED lights for the same amount of light that just a few properly cooled LED lights could make.
But LED is absolutely perfect for small, relatively cool places, where other light sources wouldn't be efficient enough, and too impractical. LED is also good for flashlights, as optics can be made better and is more efficient, but then you need to deal with battery cooling.
And for high power flashlights, "Xenon" MH is a good option.

We all sorta keep mentioning 100 Lm/W as being typical of LED tubes, but every time i see a LED product i find out again and again that they are mostly around 80..90 Lm/W (system)

And for that the Fluorescents are no worse, 3250Lm out of 36W (system, 36W Fluorescent drawing 32W on HF + 4W ballast) is not any worse at 90+ Lm/W

I keep seeing 80's-90's LPW efficiency for incandescent replacement LED bulbs.

That's certainly true, and any dust building up on the tubes will just make it worse.
But don't forget that LED is tricky to manage for warehouses with hot ceilings, as you would need to reduce power to the LED to compensate for the higher heat, and that controlling would reduce efficiency, and make it more expensive as controllers cost a lot, and you would need more LED lights for the same amount of light that just a few properly cooled LED lights could make.

That is question for properly designing the LED fixtures. Today, with the cost of the LED chips falling so down, there is no excuse anymore driving the LED chips really to the maximum power they are rated for by their maker. And that becomes even more true when high ambient temperatures are involved. Operating the LED's at fraction of their maximum rated power does not only make them to run cooler, but as well more efficient (even with the same junction temperature, lower current means higher efficacy). So for a factory ceiling light, they should take a 200W fixture model, keep all the LED's and heat fins, but use just 100W total ballasts. Of course, the fixture will emit about 55% of the light compare to when used with 200W ballasts, but everything will run way cooler and so will have at least some chance to work well even when 60degC ambient is involved.
Of course, that means starting from fixtures of double power, but these days that is not that much expensive anymore (compare to having the fixtures failing in very short time).

But LED is absolutely perfect for small, relatively cool places, where other light sources wouldn't be efficient enough, and too impractical. LED is also good for flashlights, as optics can be made better and is more efficient, but then you need to deal with battery cooling.
And for high power flashlights, "Xenon" MH is a good option.

With battery cooling you need to deal with any light source of high power. The thing is, the LED's is so cheap (compare to others) and allows to be used with so small battery, people become hesitant to invest into proper battery temperature management. And the LED the LED could be used in an intermittent manner, so allows to use as small as 10minutes burn time rated battery.
 You will kill the expensive MH in no time when doing that, so the MH flashlights are equipped by at least 10x battery size for the same power, no wonder it can stand it way better.
If you size the battery as you would do with MH (where the lamp characteristics asks for long burn time), the battery would be large enough to have no problems at all even with the LED's.

But don't forget that most people are cheap, so they get the cheapest LED fixture they can get, but that usually means pushing it to the highest power, to save on various costs, which negates any goodness lowering the LED chip power would do.

Well, I didn't said the "10 minute" light is bad, not at all.
It is just intended for an intermittent use, really like the "flash lights" used to be when invented.
The thing goes wrong when some mo**n turns it ON and let it ON till it discharges the battery at once, then there will be a thermal problem. But the main problem is him being a mo**n and using things for other purpose than designed for.
But if someone needs just brief, but strong flashes, why should he carry heavy large battery?