my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Sprocket hole noise

Author Topic: Sprocket hole noise Robert Throop Master Film Handler Posts: 412 From: Vernon, NY USA Registered: Jun 99 posted 04-25-2006 06:51 PM                     I'm installing a CP50 and CE ASR40 readers in a changeover booth with Simplex SH 1007 soundheads. There are no problems with the #2 machine. #1 however has what seems to be sprocket hole noise. I've run buzz track with two straight lines on the scope. Cat. 97 shows no cross talk yet when I play program material there seems to be sprocket hole noise on the quiet sections. Any thoughts? Thanks, Bob  |  IP: Logged Floyd Justin Newton Jedi Master Film Handler Posts: 559 From: Phoenix, Arizona, USA Registered: Jun 2002 posted 04-25-2006 06:57 PM                     Robert-- There is a lateral adjutment in your soundhead OR your slit width may be a 'hair' too wide,  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-25-2006 08:11 PM                     Red reader or exciter lamp? Do you have Dolby Digital basement readers? If you have red readers, what you are most likely looking for is a reflection/scattering of the red light being modulated by the perforations, not necessarily a direct line. Using a business card you can often find where it is coming/reflecting from...sometimes off the chamfer of the drum. If this is an exciter lamp system then th eproblem is most likely the pinch roller assembly. It is probably not hitting square on the G-1985 pinch roller. To verify, thread buzz track. Verify all are perfect. Then apply more pressure the the pinch roller in an even manner in the center of the bracket...if the buzz track does not change, all is good, if it does, the bracket has issues. Look for a crack in the barcket where the part that holds the roller and bearings joins to the part that has the pivot pin go through...the crack will be only in the upper bracket. If you can take the film out and look at how the pinch roller hits the drum (use a flashlight from below and possibly a dental mirror to get a good view). The pinch roller has to hit the drum squarly and not favor either side. Lastly, make sure the return spring on the lateral guide roller/pinch roller really is in charge of the film by having it push against the fixed roller. Steve  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 04-26-2006 03:28 PM                        Adding to Steve's post: If it is a reflection on a basement reader, disconnect the digital LED and the noise should go away. If this is the case, there is a "cover" available from Kelmar to stop the reflection. Louis  |  IP: Logged Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 04-26-2006 03:44 PM                     The CE ASR-40S reader has a press fitted lens tube to the chassis versus the more accurate threaded tube on the 30S series which may be a cause for the problem...this is after alinement, drifting parts on the Simplex head, poor release print, missing paint leaving bright bright spots of copper on the led mount, are considered....  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 04-27-2006 10:04 AM                    Don't forget that crazy dts timecode that is positioned in an area that test film would consider ok. I wonder why they don't just put a time code on the alighnment film to insure you don't pick it up.  |  IP: Logged Robert Throop Master Film Handler Posts: 412 From: Vernon, NY USA Registered: Jun 99 posted 04-30-2006 11:44 AM                     Thanks for all the replies. I think I finally fixed it although I'm not sure why. I tried moving the led around and I was not able to eliminate the noise. Yesterday I swapped leds between the two machines and voila! The noise is gone. Bob  |  IP: Logged

All times are Central (GMT -6:00)

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.