Film-Tech Forum ARCHIVE: FP30s & CP650

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Posted by Demetris Thoupis (Member # 833) on 10-04-2004, 04:21 AM:

Has anyone come across this problem on the Reverse Scan Analog Reader for the Kinoton FP30?
Not being able to get 1V Peak to peak for Dolby Tone test on the osciloscope for the above mentioned equipment therefore not being able to have proper Dolby Tone LEVEL set.
Is there a solution? If I am not mistaken in the CP500 we could boost somehow a bit more the input level from a reader (if I remember correct but I don't actually remember how) but in the CP650 we cannot. Please help
D.

Posted by Steve Guttag (Member # 268) on 10-04-2004, 08:26 AM:

Having installed literally dozens of FP30/FP38s and CP650s....I don't know what you are talking about.

First off...1Vp-p...again what are you talking about?

You show me the reader that has 1Vp-p on its output and I'll show you a clipped-all-to-hell solar cell preamp in anybody's processor. Solar cell outputs are way under 100mV range...as are reverse scan readers.

Which brings me to the buss level of most Dolby CPs...300mV...still way under the 1Vp-p you mention. Now maybe at the CP650s output you are at 1Vp-p though I don't know why you are using the p-p reference.

If you don't have the level you need, something is out of calibration. First do a complete A-chain and make sure the LED bracket is set properly and optimally. I've yet to need to raise the LED level (trim located on the LED/preamp power supply) for analog.

The one last possiblility is that you may have an older style reader with a newer style power supply. When the new light-sensitive readers came out, Kinoton changed the power supply to lower the current output to the LEDs to extend life. That that case you will need to turn the LED up and look into getting a match between your power supply and reader.

Steve

Posted by Demetris Thoupis (Member # 833) on 10-05-2004, 04:02 AM:

The A' Chain is all correct. Tripled checked. When I use Dolby Tone film I cannot get the proper levels. Even though the input level for each channel is at full (63 in this case) I can only light the bottom red LED instead of the middle two on the Dolby processor.

Posted by Steve Guttag (Member # 268) on 10-05-2004, 08:32 AM:

Try to increase the LED intensity; there is a trim on the power supply board within the projector column.

Steve

Posted by Demetris Thoupis (Member # 833) on 10-05-2004, 03:59 PM:

Steve. That is exactly what i want to do but I don't know which trim to raise??? Either I am too blind or can't read correctly through the manual. Can you please specify the exact location and which trim is for the analog LED??
Thanks in advance
D.

Posted by Steve Guttag (Member # 268) on 10-05-2004, 04:41 PM:

If you have the RSSD soundhead, then you have a dual LED power supply. It is typically mounted in the upper part of the column, just above where the upper support bar is. There is a picture of it in the FP30D operating manual in section 3.5.2 figure 3-36. Note the picture is rotated 90-degrees clockwise from actual. The trim is a single turn pot that is silver in color with a white nylon center.

If your supply is the type that can support two LEDs for an analog and digital reader, then the analog LED trim is the one furthest from you (closer to the film side of the projector. If you are confused, unscrew the fuse nearest the pot you are about to turn, the led should go out.

Good luck and you didn't hear it here [Wink]

Steve