Film-Tech Forum ARCHIVE: cat. 701 intensity level

This is topic cat. 701 intensity level in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Matt Basford (Member # 652) on 03-03-2001, 02:38 PM:

The proper led intensity is around 4v, right?

Posted by Steve Guttag (Member # 268) on 03-03-2001, 03:26 PM:

The "reder-than-red" burst should be 4Vp-p for optimum tracking but as low as 2.7Vp-p can still work well enough (just not ecouraged). I find anytime you dip below 3V things are getting dicey.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Matt Basford (Member # 652) on 03-03-2001, 10:06 PM:

I have one that's at about 2.3 and the pot is at max

Posted by Randy Stankey (Member # 64) on 03-04-2001, 12:44 AM:

Time for a new LED.

You can buy the whole bracket/LED assembly or just the LED itself. Although the LED only option is much cheaper you might as well get the whole bracket. It's a lot less trouble.

Done properly, you can change out the thing in about 15 minutes or so. If you went the cheaper LED only route you'd have to take the time to diassemble the thing, line it up correctly and reassemble it. (Don't forget heat sink compound!)

No matter which route you take it's a pretty routine job.

Posted by Steve Guttag (Member # 268) on 03-04-2001, 12:45 AM:

I'd suspect that you aren't getting good digital tracking and the "found on the first pass" leds are flickering up a storm.

It it time for a new LED for your reader.

BTW, the voltage levels are not the same for the Cat. 700 reader with the EPT lamp (or the Cat. 699 for that matter)...the incandescent lamps have a much wider range than the LED version...they run lower and still track and they optimize at about 4.5Vp-p rather than 4. They are also cheaper to run and anybody can replace the lamp.

Steve

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"Old projectionists never die, they just changeover!"