This is topic Converting a Cat 280 SR to a Cat 280T SR in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Mark Gulbrandsen (Member # 72) on 08-31-2001, 04:33 PM:
If my memory serves me correctly in this matter it involves installing a resistor on the CAT 280. Does anyone remember what value and where on the Cat 280 and or any other mods that had to be done?
Thsnks,
MArk @ GTS
Posted by Christopher Seo (Member # 7) on 09-01-2001, 12:03 AM:
I can't be of any help here, but I'm just wondering, what is the difference between a 280 and 280T? Is it just that the 280 can be used for recording and playback but the 280T for playback only?
Posted by Mark Gulbrandsen (Member # 72) on 09-01-2001, 08:59 AM:
I don't think there is any difference at all except that the 280T has something added to lock it into playback mode. If my memory serves me correctly plugging it into a 50 or 200 will not automatically put it in playback, but I may be wrong here.
MArk
Posted by Steve Guttag (Member # 268) on 09-01-2001, 03:16 PM:
It is even more minor than that. On some of the various card frames within the Dolby empire, not having a Cat. 280T can cause greef due to the resistor Mark mentioned. Certainly Ken could enlighten us.Steve
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"Old projectionists never die, they just changeover!"
Posted by Ken Jacquart (Member # 369) on 09-04-2001, 04:53 PM:
okay here's the deal...On the Cat 280T card, there is a space for a tiny jumper labeled J801. A Cat 280 card comes with this jumper in place. It is located directly next to the letter "A" on the edge connector, but actually completes a path out to pin "1" directly on the other side of the edge connector. The problem is, if you plug the card in to an appropriate cinema processor after you have installed this jumper, it will remain in record mode due to the fact that pin 1 is kept high. If the modified card is to be used in a Model 364 frame, there are a few resistor issues, but I won't go there for now...
ken
Posted by Mark Gulbrandsen (Member # 72) on 09-04-2001, 05:35 PM:
Thanks Ken!
Something definately did not sound right in this theatre. That is what I suspected as they bought these 280T's from a local Pro Audio company. Will be there later this week so I'll check them. The odd thing is that this is a CP-50 with alot of upgrades and it also has a 113C automation interface card. When you run in what should be format 05 it sounds pretty good. In format 04 which is where I always run a CP-50 with 280T's it sounds strange. Does the 113C card do this switching without removing the jumper? No need to delve into the 364 here.
Mark @ GTS
Posted by Mark Gulbrandsen (Member # 72) on 09-05-2001, 10:16 AM:
Ken,
Here is what I found on the cards. Both are very early cards. One is SN 3 308 and mthere is no place for a jumper by pin A. However there is a jumper from T to the hole right below T on this card. Could this be doing the same thing as having the jumper at A? On the second card which is SN 17 856 there is a jumper at A which I will remove.
Apparently some minor changes were made to the CAT 280 cards after the first few hundred made. If possible can you fill me in on this?
Thanks,
Mark @ GTS
Posted by Mark Gulbrandsen (Member # 72) on 09-07-2001, 12:41 PM:
Had some time this morning and ohmed out the traces on both cards. One card, the earlier one has a slightly different layout. But the spot for the jumper is there. It is just rotated 90 degrees and slightly above the pin A position so looking at it is a bit confusing. So as it turns out one card had the jumper and the other one did not. Both now have no jumper, and I have marked them as 280T cards. Sound is now also great running in format 04.
Mark @ GTS
Posted by Rick Long Jr (Member # 541) on 09-08-2001, 07:46 PM:
Here's a stupid question that I'm sure I once knew the answer to: What is the correct position for that little switch on the 280T's when used in a SRA5. Is it different when using them directly in a 200 or CP-50?
Posted by Steve Guttag (Member # 268) on 09-09-2001, 01:38 AM:
And the answer is....It doesn't make a damn bit of difference in theatre appliciations!
Steve
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"Old projectionists never die, they just changeover!"
Posted by Rick Long Jr (Member # 541) on 09-09-2001, 11:56 PM:
Thanks Steve!-Rick!-
Posted by Mark Gulbrandsen (Member # 72) on 09-10-2001, 09:29 PM:
Steve, Whats that I'm looking at on your collar? That is a wierd shot!
Mark @ GTS
Posted by Richard Hamilton (Member # 321) on 09-10-2001, 09:36 PM:
Collar??? I thought you were looking at his butt!
Posted by Steve Guttag (Member # 268) on 09-11-2001, 12:32 AM:
According to the Film-Tech Drink photos from ShoWest 2001, Mark is looking at my shoes...Mark lets face it...you are just too damn nosy...keep your eyes on your own body. People are starting to talk 
Actually, I'm wondering why that photo was chosen (not by me, btw)...I look rather beat!
Steve
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"Old projectionists never die, they just changeover!"
Posted by Brad Miller (Member # 2) on 09-11-2001, 03:23 AM:
Steve, you didn't like the other photo of you, remember? I'll post it here to embarass you anyway. 
(Now we all know why you hate platters. )
Posted by Mark Gulbrandsen (Member # 72) on 09-12-2001, 04:04 PM:
Steve,
You look beat in both photos..........? Too much booth time or what???
I can guarantee you I was not looking at your butt! But now I do remember that you had your shoes on the wrong feet and that really caught my attention. In a projector the film is threaded up with the soundtrack facing you......remember, or is this just part of being beat all the time. Its gotta be watching the reels spinning for too long if you ask me. Platters do not have that effect on people but they do get you thinking of ordering 54" diameter pizzas quite frequently 
.
Mark @ GTS