Topic Closed

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

» Film-Tech Forum ARCHIVE   » Community   » Film-Yak   » Upload your random pictures (Page 83)

This topic comprises 101 pages: 1  2  3  ...  80  81  82  83  84  85  86  ...  99  100  101

Author Topic: Upload your random pictures Ben Holley Film Handler Posts: 65 From: Texas Registered: Feb 2004 posted 11-28-2004 01:13 AM                    any SA goons here at these forums by chance?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 11-28-2004 07:25 AM                     Couldn't have been done with an ion beam as that woulda burned the phospor surface to a crispy brown. Remember... old sets have Ion Traps to prevent that. Later crt screens had a one wavelength coating of alumnium on the back of the pghosphor screen to prevent the ion burn. I wouldn't have guessed double exposure either but I did notice those orange dots when I blew it up in PS. Good trick shot! Mark  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 11-28-2004 10:31 PM                    The X Ray idea is pretty good though.  |  IP: Logged Jon Miller Jedi Master Film Handler Posts: 973 From: San Diego, CA, USA Registered: Sep 1999 posted 11-28-2004 11:55 PM                     Could a well-concealed hand held Tesla coil work?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 11-30-2004 07:34 PM                     It might but there still has to be connections for the electron gun and deflection yoke. Some of the old 7" sets from way back in the early 50's had a high voltage section that was nothing more than a tesla coil that was driven by a simple tube oscillator, usually by a 12SN7 tube. It had nothing to do with the actual deflection of the beam as it would in a TV with a Flyback Transformer. Those sets all used electrostatic type CRT's with built in deflection plates. The Tesla coil is in the lower left corner of the photo between the two tubes..... Mark  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 11-30-2004 10:00 PM                    Well when you think about it using the horizontal scan frequency to generate high voltage using a very small efficient transformer is pretty clever. I'll admit I would not have thought of it. I would been putting something akin to a neon sign transformer in each tv. Then again I don't know if I would have thought of using the Variac running a take-up platter to also be the primary control for the payout. Ingenious...but perhaps better if they'd never thought of it and made it all independent?  |  IP: Logged Luciano Brigite Master Film Handler Posts: 277 From: Sao Paulo, SP, Brazil Registered: Jan 2002 posted 11-30-2004 10:13 PM                     One of the few ( and somewhat rare) results that comes out when I have a darn boring weekend.. Sorry for the bad pic.. no digicam for me..taken with a lousy webcam.. On that board are assembled: stereo cell preamp (top/middle left) dual DNR (bottom left/center) LCRS matrix (middle/top center) and the LCR ,5 band Eqs. (entire right side). Circuits working in there: one side of preamp,matrix and 2 of the Eqs. the DRNs are missing 3 caps,one side of preamp is dead silent and one Eq is oscillating..ah well.. at least it's something comming into reality after some 3 years  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 11-30-2004 10:24 PM                     Luciano, Awesome work! Keep it up ! quote: Steve Kraus Well when you think about it using the horizontal scan frequency to generate high voltage using a very small efficient transformer is pretty clever. I'll admit I would not have thought of it. I would been putting something akin to a neon sign transformer in each tv. Just one of Philo Farnsworth's ideas that caused RCA lots of headaches and that they eventually HAD TO liscense from Farnsworth to begin producing and selling TV's. BTW: That electrostatic deflection TV HV oscillator runs at 25khz so its inaudible... something a regular flyback isn't and can't do. Its only generating a max of about 6kv for that 7" CRT. Mark  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 12-01-2004 01:24 AM                    I guess an early day videophile perfectionist if there were any would have turned down the horizontal and vertical deflection to allow the entire rectangular raster to be seen within that round tube face.  |  IP: Logged Paul Trimboli Master Film Handler Posts: 274 From: Perth Western Australia Registered: Dec 2002 posted 12-01-2004 05:02 AM                     Luciano, amazing stuff! DNR- Dolby Noise Reduction? All in the small board! Great way for cinemas to get into cheap stereo sound!  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-01-2004 05:49 AM                     Is it DNR as in Dynamic Noise Reduction? (A National Semiconductor item) or Dolby noise reduction and which variety? Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-01-2004 08:08 AM                     quote: Steve Kraus I guess an early day videophile perfectionist if there were any would have turned down the horizontal and vertical deflection to allow the entire rectangular raster to be seen within that round tube face. Oh, you mean like this........ Mark  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 12-01-2004 10:22 AM                        quote: Mark Gulbrandsen Oh, you mean like this........ Looks pretty close to an HDTV 16:9 aspect ratio! (On my display, I measure your photo showing 36 x 20 millimeters on the CRT face, or 1.80:1).  |  IP: Logged Luciano Brigite Master Film Handler Posts: 277 From: Sao Paulo, SP, Brazil Registered: Jan 2002 posted 12-01-2004 11:51 AM                     Paul, that's the idea behind that small board. I'd say that it's more of a request from owners of a few theatres I service from time to time ( two of them are still running those mono tube racks!)it started with something for myself some 3 years ago now is making it's way to real world. there aer a few issues in the circuits to figure out (the back of that board is the tech's hell,dozens of jumpers and links everywhere) and see how it'll perform when hooked up with the projector's reader. And as Steve said, the DNR is Dynamic Noise Reduction.I'm not sure if it will perform as expected since it's the first time I deal with those chips. With the exception of the DNR chips all the other components are off the shelf stuff.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-01-2004 07:40 PM                     quote: Looks pretty close to an HDTV 16:9 aspect ratio! Should I say that Emerson was very advanced in 1948 or..... That photo was taken before replacing the sweep coupling capacitors that couple the output of the sweep circuits to the deflection plates in the CRT, but after rebuilding the high voltage and DC power supplies. But it still gives a good example of what Steve mentioned. Since the high voltage is not affected by the width of the horizontal sweep as it would be in a TV with a flyback type transformer its possible to get a much smaller picture..... but hey... there's a mystique to seeing and knowing that most of the TV viewing audience was watching a round picture that came from a pickup with a square target for close to the first ten years of broadcast tv. Indeed the public didn't get the picture so to say. Mark  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 101 pages: 1  2  3  ...  80  81  82  83  84  85  86  ...  99  100  101

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.