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Quartz sockets G, GX and GY.. differences?


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Hi,

 

what's the basic difference between the different G socket types? I haven't found anything on this.

Are there any differences in mechanical stability or precision between the G, GX and GY?

(There also seems to be the less popular GZ...?)

 

I have a 1 kW fixture I want to convert from Edison type socket to G-Socket. The 9.5 socket size seems to be right choice. There is G9.5, GX9.5, GY9.5 and GZ9.5. Which one should I chose, and under what circumstances? Lamp cost seems to be around the same, with the GY9.5 being slightly more ubiquitous (probably due to the PAR64 raylights) and the GZ9.5 being quite rare..

 

Greetings,

Marc

Edited by Marc Roessler
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The different letter designation indicate different lamp base styles and in some cases different wattage ratings. A G9.5 is a TP22 1000w socket for an FEL type lamp. A GY9.5 can be: TP7 750w socket with lamp ejector; TP22L 750w; TP22H 1200w. A GZ9.5 can be: TP6 1200w socket with lamp ejector; TP23L 750w; TP23H 1200w.

You haven't stated what type of fixture you have. Is it a PAR can or a Fresnel? If you are converting from a screw base or BTR or similar bayonet base to medium bipost lamp (like an EGT), you want a G22 lampholder, otherwise for a 1k PAR globe a PAR-1 lampholder.

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Without doubt they designate different socket styles.. ;)

 

But what is the real difference when I'm not bound to and specific socket type?

There are 1kW lamps for G9.5, GX9.5 and GY9.5, so there is no real difference wattage-wise.

 

It is a fresnel fixture.. for a PAR I'd probably go with the standard PAR fixtures, just as you said.

 

Any reason for the G22? The G22 lamps of same wattage seem to be much much more expensive (almost factor 5!)....

 

Greetings,

Marc

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  • Premium Member

Marc,

 

There really isn't much difference if you are not bound to a specific socket. For what you are trying to do, I would look for the socket that best fits with your available mounting options. Don't forget to check the physical dimensions of the lamps and make sure you have enough room to easily replace the bulb.

The website that Jean-Louis provided is a real gold mine that I didn't know about!

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The "correct" replacement socket will put the lamps filement center in the center of the reflector dish. True you can shim a lamp holder, but there is more to it than that. Like filament shape. What lamp were you considering using in your re-worked fixture? An FEL? Most, if not all 1k Fresnels use an EGT. The FEL is usually seen in older lekos like the Alman 350Q or the open face Lowel D and DP. It's pretty much considered an outdated lamp and newer fixtures use HPL type lamps, fewer watts, longer life, nearly ther same lumens, more efficient. As for the cost, I'll have to disagree on the five to 1 cost comparison.

 

Try Kenedy Electric for lamps, they also sell on ebay as Lights64.

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nice webpage indeed!

 

I had planned on using an EGT type lamp, as those seem to be THE standard...as for the HPLs, they seem to more difficult to get and there doesn't seem to be much difference to the EGTs? Or am I missing anything?

(Was "outdated" referring to FEL and EGT or FEL only?)

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The FEL is an outdated style globe. Commonly used in lekos, the HPL has replaced it in newer fixtures, like the ETC Source 4. Longer life, better foucus, nearly the same lumens as an FEL, improved lamp base. In a theater application, it would mean that more fixtures could be cables to a single dimmer pack.

The EGT has the correct filement shape for the reflector in a fresnel and in a G22 socket should put the globe at the correct center height. When in doubt, check a manuafacturers catalog like: http://www.ushio.com/

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OK, seems the G22 1kWs are not really suited... The problem is that those old fresnels had large Edison style bulbs (E40) where there was plenty of room beetween the screw base and the middle of the filemant ("i.c.l." on http://www.donsbulbs.com.. something like icl=120mm) ... With the newer G22 1kW bulbs, this is much shorter (icl=63,5mm), which means that the socket will intrude into the reflector area (and possibly shade the light).

 

Old lamp:

http://www.donsbulbs.com/cgi-bin/r/b.pl/56...000w~osram.html

New lamp:

http://www.donsbulbs.com/cgi-bin/r/b.pl/cp40|240v|1000w.html

 

Does anyone know if there is any other modern 1kW lamp (halogen) which does have the filament further from the socket?

 

Thanks & Greetings,

Marc

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Are you saying that your concerned that a portion of the ceramic lamp base may be in front of the reflector or a portion of the socket itself? If you look at a 1k fresnel fixture (6" lens) with an EGT globe, you will see that the lamp base does sit up in front of the reflector. The socket mounting point in your fixture may have to modified to put the center of the lamp in the center of the reflector.

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I meant the ceramic lamp base, but actually they will both be inside the mirror's diameter...

the lens of the 1kW fresnel has a diameter of 21 cm, the mirror has a diameter of 14,5 cm.

(It really is a 1 kW... the 2 kW's were even bigger! Probably due to the large bulbs used back then...)

This means that a lamp with an icl of 63,5 mm (i.e. 6,35 cm) has both the ceramic lamp base and the ceramic socket intruding into the mirror area. So what I need would be a 1 kW halogen lamp with an icl large enough so neither socket nor lamp base intrude into the mirror area. Does anything like this exist?

Another option would be retrofitting a new-style ARRI 1kW mirror (of much smaller diameter!), but I don't really know what effects this will have coupled with the then (in relation) extra-large fresnel lens...?

 

Greetings,

Marc

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