So I've seen people say on the forum that these "metal halide" on ebay are actually SBMVs. I've been looking for clear SBMVs for quite a while

https://www.ebay.ca/itm/PREMIUM-QUALITY-SELF-BALLASTED-METAL-HALIDE-LAMP-400W-E40-5000K-HYDROPONICS/282148014398?hash=item41b155093e:g:c2UAAOSwPcVVuSIJ

Yeah the lack of the white heat insulating paint on the arctube makes it look more like a mercury vapour arc tube to me. Interestingly it uses a halogen lamp and opposed to a standard incandescent filament to ballast the arc tube though. Perhaps the metal halide was a translation error from the halogen lamp in it.

That's a real SBMV lamp but it's 240v and so you won't be able to run it off 120v power, which might be an issue if you want to use it for a moth trap.

He can always run it off the dryer or stove power. The only issue I see is they have an E-40 base which I believe is a bit larger than our mogul E-39 socket .

The E26 sockets seem to accept E27 lamps pretty well from experience but I don't know about E39 sockets and E40 lamps. I don't have any to test lol.

Yeah I had to use a giant 2kVA step up transformer to fire up my 240v SBMV properly.

The E26 sockets seem to accept E27 lamps pretty well from experience but I don't know about E39 sockets and E40 lamps. I don't have any to test lol.

E26/E27 do seem to be close for most purposes, but E39/40 is a different matter. I have several E39 lamps from the US and none will fit comfortably in an E40 holder, nor will E40 lamps seat properly in E39 holders. So much so that we use an adaptor where necessary.

That's a real SBMV lamp but it's 240v and so you won't be able to run it off 120v power, which might be an issue if you want to use it for a moth trap.

I'm quite new to lights so sorry if this is a silly question but what happens if you run it with lower voltage?

I'm quite new to lights so sorry if this is a silly question but what happens if you run it with lower voltage?

Nothing, it just won't light.

Do you use a car battery to operate your lamps?

If so you could get a 12v to 240v inverter.

Do you use a car battery to operate your lamps?

If so you could get a 12v to 240v inverter.

Depends on the lamp wattage, inverters big enough to operate high wattage stuff don't come cheap. And they draw a LOT of amps at 12V 

Not sure how they'd handle discharge lamps either 

Do you use a car battery to operate your lamps?

If so you could get a 12v to 240v inverter.

First 400W means 40A at 12V, so quite impractical from a battery (car battery is able to deliver such current barely 20 minutes). Starting from higher battery voltage would make it feasible, but demand more batteries...

Second problem could be with the modified sinewave inverter output waveform. First it contains quite long gaps and second the shape itself may mean overload of the incandescent section. To prevent these problems you would need true sinewave inverter.

Gnerally a step up transformer would do way better job here...

Yep, those are definitely SBMV, SBMH is a lot more complex to achieve and can't be done with a tungsten filament ballast, you need electronics.

I bought a couple just out of curiosity. They're ok as far as cheap Chinese stuff goes, but I wouldn't want to use them in anger.