Film-Tech Forum ARCHIVE: SG-1 pink noise generator

This is topic SG-1 pink noise generator in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tom Wienholt (Member # 1510) on 11-09-2010, 12:03 PM:

Does this generator need to be calibrated periodically? If so, how is this done? I do not see any trimpots for making adjustments.

Posted by Steve Guttag (Member # 268) on 11-09-2010, 04:47 PM:

I've never needed to calibrate ours...try calling Component Engineering...they made it and are still in business (and still offer it new).

Posted by Tom Wienholt (Member # 1510) on 11-09-2010, 09:16 PM:

Steve,

Thanks for the info. I was previously told that pink noise generators should be calibrated periodically. Is there a proper way to at least test the output level to make sure it is correct? Thanks.

Posted by Mark Gulbrandsen (Member # 72) on 11-09-2010, 11:32 PM:

I check all my PN cards a couple times a year on a Hewlett Packard 3580A Spectrum analyzer. Several of my cards are in excess of 20 years old now and capacitors do dry out and change value over time.

Posted by Louis Bornwasser (Member # 3063) on 11-10-2010, 02:46 PM:

Since these cards are typically also used to set reference level, it is possible that LEVEL could vary. The Dolby card does not have a level preset, but the Component one does.

I test 3 or more cards for level (Dolby) and if they all agree, that's it. The Component card I set to agree with the Dolby card. (small pot on edge of card.) Louis

Posted by Tom Wienholt (Member # 1510) on 11-10-2010, 07:41 PM:

Louis,

For some reason I do not see the pot on the edge of my sg-1. My sg-1 is about 8 years old. Am I just not seeing it?

Posted by Louis Bornwasser (Member # 3063) on 11-10-2010, 09:17 PM:

I will look in a couple of weeks when I make it back to the shop. Louis