Source Four Lamp Bases

[icewolf08]

Ok, it could be just me, but I have been noticing a bunch of very minute, but majorly inconvenient differences between lamp bases and Lamp caps on source fours.

First off, apparently there are two designs of the rear of the fixture where the lamp cap meets the fixture. One has 4 pins that protrude from the fixture, and the lamp caps have matching holes allowing them to fit. This mean that a lamp camp without these holes doesn't fit these instruments, but the lamp caps from these instruments fit all others.

The other thing, is, have they changes the actual porcelain lamp base? Because I went down to my supplier to pick up some replacement porcelain bases, and they only fit in the 750w caps. It is driving me nuts. Does anyone know if there really is a difference or what the two different part numbers are (ETC only lists one on their site)?

[Footer]

off the top of my head, no, but I know its scribbled on the wall of a few light shops in this country.... I like writing things on walls... My all time favorite S4 thing is dealing with the first generation ones with the shorter yokes.. if you put one of the new base caps with the handle on them, they don't go to 50/50 anymore because the handle hits... GENIOUS

[jmabray]

Yes there are differences.

The TP220 or TP22 Part that is the lead with the piece of porcelin attached is different. The first version of the part came in 4 separate pieces. 2 leads, the porcelin and the silica piece. The second version has all those pieces but they are riveted together.

The lamp cap difference that you are talking about is the difference between a very early version and the later 750w version.

Call ETC tech support and they can help you out about how to get these to work together.

Jeff

[Lightingguy32]

The Standard Source Four Socket as of the end of the year 2006 is now the Osram TP-22H HPL socket which has a max rating of 750Watts. The standard Source Four on the market these days is now by default rated for at most 750 watts. The lamp caps only difference between the original 575 watt run and the 750 watt run is that the 750 watt lamp cap incorporates a nuetral pin socket for the 3rd pin on a HPL 750w lamp. How ever I am clueless to what you mean by a different casting design of the rear housing of a source four fixture. The casting between the lamp cap and the reflector assembly has never changed a bit (maybe a little to compensate for the extra heat of a HPL 750). I have compared the fixture specs between a source four 750 and an original 575watt source four back from 1993. The rear castings are identical except that the old one from 1993 is rated at max at 750watts.

[Lightingguy32]

Originally Posted by jmabray

Yes there are differences.
The TP220 or TP22 Part that is the lead with the piece of porcelin attached is different. The first version of the part came in 4 separate pieces. 2 leads, the porcelin and the silica piece. The second version has all those pieces but they are riveted together.
The lamp cap difference that you are talking about is the difference between a very early version and the later 750w version.
Call ETC tech support and they can help you out about how to get these to work together.
Jeff

Actually the original lamp cap was four pieces, 2 each of porcelain and ceramic. Now the socket is a single piece of ceramic and steatite with a floating contact construction to insure that the lamp pins contact the electrical contacts in the socket.
Here is the link to the spec sheet:http://dafnwebpd.sylvania.com/idmweb/doccontent.dll?LibraryName=ecomcspd^dafnctpd&Syste mType=2&LogonId=d73809c31d1c4740258b153e5040d58d&D ocId=003689651&Page=1
keep in mind all source fours that are produced (2006 on) now have this Osram TP22H socket as the standard socket.

[icewolf08]

This is all very helpful, thanks. Lightinguy, your link was dead, will have to try searching Sylvania's site.

[Lightingguy32]

I am guessing you still have the older version of the TP-22 socket where they used hollowed out gold cylinder contacts insulated by mica and ceramic. These sockets are ok but usually end up having loads of issues and eventually they will short out and die or cause large amounts of arcing. My advice is if you have the money, update all of the old- Gold style TP-22 sockets with the new Osram TP22H socket.

[avkid]

Originally Posted by icewolf08

Lightinguy, your link was dead, will have to try searching Sylvania's site.

I went through the link and removed some characters to get the base site, it appears to be a database that requires a login.
http://dafnwebpd.sylvania.com/idmweb/home.asp

[ship]

"One has 4 pins that protrude from the fixture, and the lamp caps have matching holes allowing them to fit."


Some of the really old 575w fixtures did have four keyway nubs that would not allow the new 750w cap to work. Believe these were on the fixture side - just square shapes sticking up. Been a few years since I have seen any, but over the years of those not sold off, I did initially grind away at a huge amount of keyways.

I followed ETC's direct recommendation to cut off than grind flat the keyway nubs. There was no other differences in the fixture other than at the lamp base between and cutting would be fine so it would accept the 750w caps.

[icewolf08]

That is good to know Ship. I had never noticed it until the hang for Les Mis last month. The best part of that story is that the LD was Karl Haas from ETC and he had no knowledge of that either.