Film-Tech Forum ARCHIVE: cat 700 bulb

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Posted by Mike Carro (Member # 232) on 09-15-2003, 05:37 PM:

I know I should know this but what is the exact bulb to use for the cat 700. I very rarely have to change mine but I think it's due and I can't find a number or specs anywhere.
Thanks
I know it's a 10 volt but what's the wattage?

Posted by Art Averett (Member # 367) on 09-15-2003, 06:39 PM:

Mike, the lamp is coded EPT. An easy way to remember is Early Pregnancy Test.

Posted by Aaron Sisemore (Member # 145) on 09-15-2003, 07:26 PM:

Another alternative to the EPT is the EXZ bulb, preferably the one made by Osram.

-Aaron

Posted by Steve Guttag (Member # 268) on 09-15-2003, 08:51 PM:

Another tid-bit...only the GE version of the EPT works. Apparantly the EPT wasn't as well standardized as it should have been so other forms of EPT will have drastically inferior video levels.

Steve

Posted by Aaron Garman (Member # 1653) on 09-15-2003, 08:58 PM:

We just replaced one of these. Anyone have an estimate on how often this is done or should be done?

AJG

Posted by Mike Carro (Member # 232) on 09-15-2003, 09:05 PM:

Thanks to all I appreciate the help

Posted by Aaron Sisemore (Member # 145) on 09-16-2003, 02:42 AM:

quote:
We just replaced one of these. Anyone have an estimate on how often this is done or should be done?

When the error rates start going up or the system begins reverting to analog, check the bulb. If it shows even the least bit of 'fogginess' on the reflector, regardless of the condition of the bulb filament , then the bulb must be changed.

-Aaron

Posted by Chris Hipp (Member # 1788) on 04-29-2004, 12:02 PM:

Do any other A-chain adjustments need to be made after changing the bulb? I can't see how it would as long as the light tube is not removed.

I have four cat 700 readers with their original bulbs from 1998. We rarely used the dolby before, but I would like to get away from SDDS as much as I can.

Posted by Scott Norwood (Member # 30) on 04-29-2004, 12:05 PM:

You should just be able to replace the bulb. Usually, you'll see the error rate drop noticeably with a new bulb.

Posted by Mark Gulbrandsen (Member # 72) on 04-29-2004, 01:19 PM:

"Another tid-bit...only the GE version of the EPT works"

Actually Steve, you are wrong on that statement. The WIKO version of the EPT works just as well as the GE version does although the reflector is quite different. Used many of them when I was at GTS and obtained just as good of results of video level and life span.

"but I would like to get away from SDDS as much as I can."

Yea, but SDDS sure sounds miles better than SRD does. If you ahve 3000's SDDS should be no more problem to play back then SRD ocasional is. If you have the older SDDS units then oh well...but they can be made to work pretty darn reliably if your chain gives a hoot.

Mark

Posted by Darryl Spicer (Member # 711) on 04-29-2004, 02:35 PM:

We had to get some from dolby because I was having problems finding it here locally. They sent the GE type. Turns out after furthur investigation that there is a problem with the power supply or socket. The reading withour bulb was 10V but the reading with the bulb installed with a load on it was 3.8V. Dolby is sending us another power supply on a repaor/exchange. I hope this remedies our little problem we are having here. As far as the wattage of the bulb as asked in the original question it is 42Watts for future referance.

Posted by Mark Gulbrandsen (Member # 72) on 04-29-2004, 03:42 PM:

Darryl,
Don't waste your money on this Dolby scam! All thats wrong is the power supply connectors are cooked. This is akin to the USL power bypass switch failing and how many bought new or replacement supplies that didn't need to. Just remove the connectors from the PCB and solder the wires directly to the board. Can't tell you how many 700 power supplies I've seen this happen to but its pretty much every one that I come in contact with. My most recent one was two weeks ago in Wyoming. I have made it a habbit of removing the crap Molex connectors and soldering the wires directly to the board for several years now. If you do yours you can chuckle with me over the available unused pins that Dolby doesn't use for the DC connections that could have alleviated this problem. If you replace it your new power supply will also eventually follow the same route down the road in a few years USL is wise and now leaves the power backup switch off all new supplies!!
Mark

Posted by Steve Guttag (Member # 268) on 04-30-2004, 06:38 PM:

Mark,

I'm happily corrected on this statement. I believe it was OSRAM's EPT that simply had a different focal point so the light was not efficient with Cat. 700 set up. Apparantly, even though there is an ANSI EPT, it isn't too well standardized.

Now Wiko I've had mixed results with in general. They are popular now due to cost but I've found the quality of their minature lamps to be quite questionable. I can't speak to their EPT lamp as I have never used them. Thanks for the tip.

Steve

Posted by Chris Hipp (Member # 1788) on 04-30-2004, 07:37 PM:

quote: Darryl Spicer
We had to get some from dolby because I was having problems finding it here locally. They sent the GE type

You can order the GE bulbs from Grainger for about $36.

I guess I should have said that I want more options than just SDDS. We just got four new cp650/cat701 readers for you big houses and I have four cat700 readers and two da20's on carts. I'm also getting my DTS6D's repaired right now. I just hate having broken down equipment lying around. The DA20's are dropping out but I am pretty sure putting new bulbs in will fix that.