Film-Tech Forum ARCHIVE: Warbling with Analog Cyan Dye Reader

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Posted by Ian Woloschin (Member # 3709) on 05-02-2006, 09:31 AM:

Ok, so I'm new here. Yay for me finding a place that might be able to fix this problem [Big Grin]

.

wI'm the "Head Projectionist" for my university's 35/70mm projection program. Basically, I made the mistake of getting licensed (yay Mass.!) and now I'm responsible for two DP70 projectors (single screen, we don't have the money for platters). This is all hooked into a stock CP55 which then sends the channels to both booth speakers and house speakers.

Last October we updated our projectors with new sound readers, so we could show cyan dye tracks.

http://www.kinotonamerica.com/cinemaEquipment/dp70.asp

On one of my projectors (P2) the sound gets all warbly every now and then. When I use my finger to push the film laterally over the light source it seems to get a little better, but it could just be me. It's very intermmitant, it'll be there for the first reel of a movie, but the third reel it's gone.

We do plan for next summer (2007) to do a full upgrade to the lecture hall/theater, including switching to Dolby Digital, but until then I'd like to figure out why we're having this warbling issue.

Since I am a student, I'm actually going home for the summer (4 hours away), so I may not be able to try any ideas immediately, but the old Head Projectionist who graduated will be around to try and fix things.

Posted by Pete Naples (Member # 761) on 05-02-2006, 12:00 PM:

Insufficient pressure from the lay on roller.

Scan drum bearing end float incorrect, probably too tight, causing it to bind.

Scan drum bearings could be brunelled, as recently as last week I had to change a pair of bearings on a year old FP30 which had started to warble, the op side bearing came out as two journals and a pile of orange dust!

Posted by John Pytlak (Member # 331) on 05-02-2006, 12:07 PM:

"Warbling", wow and flutter, mistracking, etc. are mechanical issues with the sound reader, not specific to whether you have a red LED reader.

Posted by Ian Woloschin (Member # 3709) on 05-02-2006, 12:27 PM:

John: The problem only started when replaced our old exciter lamp readers for newer red light readers, which leads me to think it's something mechanical on the new sound reader.

Does anyone know of anything specific to my projector and sound reader that I can do to attmept to adjust? I'm kind of afraid of moving things around and making the problem worse, though I do have until late August before another movie will be run (school year ends today). Also, try to use laymens terms if possible, I've been doing this for less than 2 years so I don't know all the terminology yet.

Posted by John Pytlak (Member # 331) on 05-02-2006, 12:38 PM:

quote: Ian Woloschin
The problem only started when replaced our old exciter lamp readers for newer red light readers, which leads me to think it's something mechanical on the new sound reader.

Does anyone know of anything specific to my projector and sound reader that I can do to attmept to adjust? I'm kind of afraid of moving things around and making the problem worse, though I do have until late August before another movie will be run (school year ends today). Also, try to use laymens terms if possible, I've been doing this for less than 2 years so I don't know all the terminology yet.

Have you talked to your theatre equipment dealer about the problem? Sounds like something simple that might be remedied with a phone call to someone familiar with your installation.

quote: Ian Woloschin
It's very intermmitant, it'll be there for the first reel of a movie, but the third reel it's gone.

Are your projectors in a cold environment when not in use? Sounds like they "loosen up" with a few minutes of use.

Posted by Ian Woloschin (Member # 3709) on 05-02-2006, 12:42 PM:

Haven't had a chance to get them in yet.

The problem is that when it was installed, I tested it with the two techs who came to install it, and we had no problems until a few months afterwards, and it's been so intermittant I didn't want to call them in and use a service call up and have the problem not occur.

Posted by Monte L Fullmer (Member # 2797) on 05-02-2006, 03:03 PM:

did you keep the same photocell arrangement and Jaxlights were installed - why of the "red reader" and not the LED reverse scan readers..

check this site out www.bacpinc.com and see if you recognize any of these readers for those DP-70 Norelcos..

-monte

Posted by Steve Guttag (Member # 268) on 05-02-2006, 05:37 PM:

If you have the genuine DP70 RSSD reader as shown in your link, then look at the two rubber O-rings that are on the pinch roller...if they are black, they are most likely very puckered and need to be replaced with the current Green ones.

That was the most likely cause. Alternately someone may have set the damper improperly or even the loop sizes are not set correctly to work with the reader.

Steve

Posted by Mark Gulbrandsen (Member # 72) on 05-03-2006, 08:00 PM:

Its too bad if you bought the actual Kinoton units... I wouldn't take one for free! It also costs ALOT more than the BACP seperates do. Considering who made the Kinoton it is indeed very shabby stuff . The original Phillips analog soundhead is incredibly well built and performs far better than the new one in almost all aspects... and most importantly in the original scanner the film is supported only at the very outside edges of the film. For analog the BACP conversions are far better from my experience! Wether they use Buna-N or Viton O-ringsThe whole O-ring idea is also just plain stupid... an idea that didn't fare well for Christie either.

If by luck you still have the original sound reproducers they probably need to have the drum bearings cleaned and lubed. Also be sure that someone did not install bearings with grease in them or with seals on them, both will cause excessive drag on the scanner and it won't be able to get to "speed".. Shields on the bearings are acceptable though... and above all after the bearings are scrupulously clean oil them with some 30 weight equivalent synthetic oil. This service should normally be done about every two years on a DP-70. With clean freshly lubed bearings its not uncommon for a Phillips scanner to continue to rotate for in excess of 60-90 seconds after the film runs out! Also be sure the proper spring pressure is set up on the lay on roller so the scanner gets to "speed" in less than 5 seconds.

Mark

Posted by Ian Woloschin (Member # 3709) on 05-03-2006, 10:58 PM:

Heh, I had just become Head Projectionist after these were bought and installed, so I didn't have too much to do with the decision making behind them. We needed to upgrade the sound readers to read Cyan Dye films though, as we did indeed still have the original Phillips sound readers (and I held on to them, though they're pretty much just acting as paper weights at the moment).

Also, we're not a traditional theater, we only run two showings a week (occasionally more), so our projectors see very little run time. It's less fun...but keeps my GPA above zero [Wink]

Posted by Steve Guttag (Member # 268) on 05-03-2006, 11:00 PM:

Gee Mark...do you have any real experience with the Kinoton RSSD readers? I mean, they only track better than any of the others for analog or digital. The O-rings do just fine except for a bad batch of them...it isn't an inhernet flaw of the design.

I've put in the Kinoton DP70 reader...about as fast and clean of an installation as I've seen...truely a bolt in. Other than having a set of bad O-rings, not a lick of trouble.

Posted by Michael Schaffer (Member # 1204) on 05-03-2006, 11:19 PM:

Well, we can't really judge and appreciate these readers unless we use them to play the sound back through the Panastereo processors. Us people who use inferior products such as the ones made by Dolby and some other manufacturers don't really know what we are talking about anyway.
BTW, when did you have that bad batch? I seem to recall we had some probs with the O-rings in 1999 or so, but not for long and never afterwards.
Even that was never perceived as a real problem by us, it took less than a minute to change them, done, problem solved.

BTW, Ian - the pressure with with the roller presses against the sound drum should be around 300g. You can check that easily with one of those pull thingies, I don't know what they are called in English, spring balance I think. That's probably not your issue here, but it might be good to know.

Posted by Mark Gulbrandsen (Member # 72) on 05-04-2006, 04:12 AM:

quote: Steve Guttag
Gee Mark...do you have any real experience with the Kinoton RSSD readers?

Yes! And......

Where in my above post did I criticize its SRD playback? What I did criticize was its vastly inferior "tin can" construction quality.

Mark

Posted by Michael Schaffer (Member # 1204) on 05-04-2006, 04:59 AM:

The "tin can" is just the outer cover. What's inside is so sturdy, you could hang an elephant from it.

Posted by Steve Guttag (Member # 268) on 05-04-2006, 06:42 AM:

quote: Mark Gulbrandsen
Where in my above post did I criticize its SRD playback? What I did criticize was its vastly inferior "tin can" construction quality.

It is actually of a superior construction quality than the rest. It is very precise in its alignment of the film to the reader, very precise in its alignment of the readers to the LEDs...in short, very precise. At least CE realized that they needed to make new mounts to get things to align in their retros (they don't make any for Kinoton). The proof is in the reproduction...the current RSSD out performs all others at the moment. It does so well on digital because of this...as such it does well on analog too (analog is an easier track to scan). You are truely judging a book by its cover...er tin can. Which, by the way covers up their, otherwise, exposed reader boards.

To say that you wouldn't take one even if for free is your loss.

BTW Mike....I have those tin can readers of Kinoton playing through Panastereo processors in such shabby places like the American Film Institute, National Archives, National Gallery of Art and no one felt like they had a crapola analog film reader...even with the precise Panastereo tracking.

As for the O-rings...our bad batch came in 2003 or there abouts...they would not last very long at all. About 1000-hours or LESS and then pucker up to the point of worthlessness. Note, only the O-ring under pressure would pucker (inboard). Switching to the green O-rings has had the problem go away permanently. Also, our black O-rings going back to about 2000 have had zero problems.

[ 05-05-2006, 08:51 AM: Message edited by: Steve Guttag ]

Posted by Richard Fowler (Member # 893) on 05-04-2006, 09:08 AM:

Other projector manufacturers use the O ring set up with excellent results.