Wow, that is an efficiency nightmare.

My pick is probably my purple Diazotype reprographic 400W MH lamp (my profile picture). Don't get me wrong, it does look cool when lit, that is why I chose it as my profile picture. But there are a few reasons I am not exactly a fan of it:

- First HID lamp I ever got, looks 100% normal, was expecting it to be normal/usable
- Light output is not usable, may or may not contain harmful UV (nobody seems to know)
- Cycles on it's appropriate ballast (even though arc tube looks pretty new), can only be run up nicely with added CWA capacitance
- BT-37 takes up a lot of my space, and I don't ever even take it out of the box anymore
- Even if it did work right and wasn't harmful, the hour rating of these kinds of lamps is apparently crud anyway

Honestly if I could magically wake up and have this lamp transformed into a normal 400W MH, that would be great. It is just a waste of my space. But I am not gonna just throw it away because they aren't super common, maybe some day someone will give it a loving home lol.

HID lamps can invariably rectify at times and this is normal - especially at starting. Of course the ballast must be able to withstand that, without damage and without going into protection mode. Perhaps that is taken into account with the higher rated capacitors to an extent

In PC power supplies using the old half bridge circuit (where the outcome of any imbalance would be saturation of the transformer) they solved this with a film capacitor in series with the transformer. Is this present in any HID ballasts ?

Last time i was at the thrift shop, i grabbed a Calex GU10 CFL spotlight and it is just hilariously bad.

Why? You're looking at the tops of the U-bends of the discharge tube. The 'reflector' is cylindrical so most light just gets bounced around the cylinder. It runs extremely hot, you cannot touch the thing after it's been running for 15 minutes. The internal reflector is a piece of aluminium so almost all heat emitted by the discharge tube just gets sent right back into itself. The rest of the housing is plastic.
It draws 9w of power and puts out a claimed 190lm, so the efficiency is essentially on par with some of the better halogen spotlights. Yet it claims to offer 80% energy savings.

So what are your worst ones, that you keep around just because they're so awful?

Another one worth a mention here is a self ballasted blacklight MV lamp. I'll dig that one up later and post it. Very sloppy construction, mediocre output.

Virginia (Spotsylvania County)

LOL that's really apt

Yeah, it was pretty amazing for its time. Imagine if they made a fluorescent version with the ballast and starter in the base alongside the radio. I dunno, it's pretty cramped in there, I think they might have to put the gear in the space in the stem, above the radio.

Ahh I see, I did not know that the UV blocking dopant affected the quartz like that. Makes sense.

@Medved
I have heard of those fixtures with integral starters as well, similar idea.

@RRK
I never really considered that it might be anything other than a glow starter, but I suppose that is possible. That would certainly be better.

It is a real shame there isn't any free space inside circline lamps. Of course you could make them so that the base is bulkier (less tube, more base) but at that point it's too much effort.

You do have a point that EOL lamps are likely to be noticed faster in a residential environment. And even if the starter does go bad, the ballast isn't useless. Just needs an external starter (if you have space for it), then you are back in business.

Over here in Southeastern PA, we got around a foot, with about 1.5-2.0ft snow drifts.

@wide-lite 1000 — ditto on the snowblower and low temps for the next 7-10 days!

Good glow starters in fact last a lot. And probably can outlast a few tubes if not abused by constantly blinking an EOL tube. BTW, at home there is a better possibility someone will notice an EOL tube timely and turn it off and replace quickly.

Some decent ballasts use way more long lasting starters (like thermal starters - a bimetal switch with heater connected in series with the working circuit, then way later indeed some form of electronic/FEC starters), but there really were products using regular glowbottle starter as a non replaceable component.
Have seen these not as ballasts, but as parts of light fixtures, those very cheap kitchen undercabinet T5 fluorescent lights, before the cheepeese electronic ballasts took over. These were really able to last only as long as the tube did.