Film-Tech Forum ARCHIVE: Sound Drum Problem.

This is topic Sound Drum Problem. in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=007633

Posted by Matthew Stevens (Member # 2167) on 11-23-2005, 05:23 PM:

Hey I'm having a problem with my second projector, every time a splice goes thru the sound drum, a "honking" sound occurs. You could describe it as "Fog Horn" noise.

It only occurs in my second projector, never my main projector. The two projectors are exactly the same. Same sound drum, same splicing tape, same everything.

The sound drum is a red led, B.A.C.P. LED. Sound drum is a simplex.

Anyone have an idea on what's happening?!?

Posted by Steve Guttag (Member # 268) on 11-23-2005, 07:50 PM:

My guess is that your lateral alignment is not as good as it could be on the 2nd projector...thus, when a splice goes through, it is allowing the reader to read the perfs until the lateral guide roller corrects it.

Additionally, you might want to give the soundhead lateral guide roller assembly a good look...if the spring loaded side (inboard) is not working smoothly (it shouldn't be mushy either) then it needs some service.

In either case, Buzz track test film (P35-BT) is required to get things aligned if or when the lateral guide roller is working properly.

Steve

[ 11-24-2005, 12:50 AM: Message edited by: Steve Guttag ]

Posted by Monte L Fullmer (Member # 2797) on 11-24-2005, 02:04 AM:

..yep, could be picking up the timecode through the optical when the splice goes through...had that happen to me as well.

Posted by Michael Schaffer (Member # 1204) on 11-24-2005, 05:06 AM:

I think the "foghorn" characterization points more to the reader seeing the perforation when the splice goes through.
BTW, I just wanted to point out that not every single part in the sound head is called "sound drum".

Posted by Louis Bornwasser (Member # 3063) on 11-24-2005, 09:02 AM:

Simplex sound head: honking noise on splice. My guess is that you either have an alignment problem OR a small crack has developed in the top piece of the lateral guide swivel. This causes the felt/rubber roller to not track straight and any interruption (splice) causes a serious scan of the perfs. I've seen it more than 20 times. Louis

Posted by Matthew Stevens (Member # 2167) on 11-30-2005, 04:47 PM:

Found it, laterial alignment was rusted!!! My tech polished it and put it back together. Works great now.