Film-Tech Forum ARCHIVE: Christie AW-1, 2,3 difference?

This is topic Christie AW-1, 2,3 difference? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by John H. Crawford (Member # 3086) on 08-19-2005, 04:18 PM:

What's the difference between the AW-1, AW-2, and AW-3 platters? Is it mechanical?

Posted by Louis Bornwasser (Member # 3063) on 08-19-2005, 05:02 PM:

The AW-1 had a fibreglass disc and neon lights as a source. The AW-2 had "improved" L.E.D. sensors and a better disc (metal band around it. Both were made by Bob Potts in Champaign/Urbana.

The AW-3 is an all new design about 1975 designed & built in Los Angeles.

Bob Potts made many, many platters most of which were Ok to excellent. Unfortunately the AW-2 and AW-1 were not good; certainly not for 2005. Few parts available; much tweaking for the period of time until you give up and discard the unit.

More if you need it,

Louis

Posted by Tim Reed (Member # 137) on 08-19-2005, 05:45 PM:

FWIW, the quadracs in the AW-1 (the active element in the motor speed control circuit) were specially-made by Motorola for Christie/Bob Potts. When they discontinued production of that particular semiconductor (or Christie stopped ordering them, whichever), the AW-1's were effectively dead in the water.

Although, and contrary to what Christie told me at the time, I have used off-the-shelf quadracs from Mouser to successfully rebuild dead AW-1 cards.

Which reminds me of another great platter by Bob Potts... [drum roll] the Simplex Aero-Matic (SAM)! The air platter. What a noisy, Rube Goldberg hunk o' junk! [Eek!]

Posted by Ken Layton (Member # 133) on 08-19-2005, 05:59 PM:

Seems to me I also was able to get those semiconductors crossed over to something that worked. This was several years ago.

Posted by Gordon McLeod (Member # 33) on 08-19-2005, 06:31 PM:

Usually a quadrac can be replaced with a diac connected to the gate of a triac

and then remember the applied energy platter and its design

Posted by Tim Reed (Member # 137) on 08-19-2005, 07:51 PM:

Didn't need to. There were several flavors of quadracs readily available. Christie just wanted you to believe that the one they used was so special, nothing could replace it. That way, they could sell you a new platter. Heard that song before, huh?

Yes, Ken. I think I found the specs to a near-neighbor in an old RCA SK book, picked one from Mouser that was close, and bingo! Worked like a champ. Bought me a handful for a couple of bucks and soon had no more dead cards lying about. I love making the "impossible" happen. [Wink]

Posted by Mark Gulbrandsen (Member # 72) on 08-19-2005, 08:14 PM:

quote: Tim Reed
Bought me a handful for a couple of bucks and soon had no more dead cards lying about. I love making the "impossible" happen.

Tim,

Shame, Shame [Wink]

on you for fixing those junkers and doing a dis-service to your customers. I dread customers that would even want to repair one of those. They ARE NOT theatre operators. Even a Stupid platter is better than those thangs. I have a customer in Utah that keeps his only AW-2 running... and believe me he is not a theatre operator!

The Air Platter was not that bad. One of them still survives running somewhere around the mountain states.

Mark

Posted by Sam D. Chavez (Member # 1841) on 08-19-2005, 11:28 PM:

Does anyone know what the air platter was called in not so polite circles?

Posted by Tim Reed (Member # 137) on 08-20-2005, 12:24 AM:

quote: Mark Gulbrandsen
Shame, Shame on you for fixing those junkers and doing a dis-service to your customers.

Mark... heh-heh... who said this was in a theatre? The AW-1 was mine, picked up with a bunch of other stuff from a dead drive-in booth I bought. You know me better than that! [Big Grin]

Sam... 'the platter that blows'? [Wink]

Posted by Ken Layton (Member # 133) on 08-20-2005, 09:59 AM:

Now I remember what it was I used since it was something I already had on hand to repair those boards. It was the triac and diac that I normally use to repair the lamp dimmer circuitry on English Mark Dart 6000 series dart game power supplies. I had tons of them on hand since they were such a high failure item. I remember either buying them at Mouser or Radio Shack Commercial. They didn't cost much at all. I think it was about a buck apiece for the triac and around 60 cents for the diac.