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  #166  
Old 04-04-2011, 05:25 PM
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Tom-BLOWN AWAY by yr work....Good Job !
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  #167  
Old 04-05-2011, 12:01 PM
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URL Test 4

[IMG][/IMG]

Phil.....Putting [IMG] [/IMG] around http://pic70.picturetrail.com:80/VOL.../322339657.jpg
produced same size picture. I'm going to try it next with PhotoBucket.

Last edited by Tomcomm; 04-05-2011 at 12:08 PM.
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  #168  
Old 04-05-2011, 12:19 PM
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ULR Test 5



Phil....The [IMG].............[/IMG] seems to work with Photobucket freebi ok! Its slightly larger than my 1024 X 768
monitor but has positioning sliders to cover entire native pic size. Hey, when I get into posting RAW camera
screenshots this is what its going to be.............Tom

Last edited by Tomcomm; 04-05-2011 at 12:42 PM.
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  #169  
Old 04-05-2011, 12:43 PM
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Do you have vid in mod ?
Can someone link to RCA Video In adapter schematic again please ?
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  #170  
Old 04-05-2011, 03:39 PM
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that looks great!convergence looks very good and the color is fantastic.beautiful picture and thanks for pic
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  #171  
Old 04-06-2011, 11:47 AM
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Ext Video Input

Newvista...........Here's a tube version of the RCA external input driver for the Roundies I got from Pete D. Hope you can use it..........Tom
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File Type: jpg Copy of pete's ext video circuit article.jpg (145.8 KB, 81 views)
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  #172  
Old 04-06-2011, 03:49 PM
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Thanks for that diagram, Tom (and Pete). An "Official RCA" video input mod!
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Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did."
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  #173  
Old 04-06-2011, 04:43 PM
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Here's the complete article, which I got from John Folsom.

http://antiqueradio.org/art/BROADCAST_NEWS_0656_1.jpg
http://antiqueradio.org/art/BROADCAST_NEWS_0656_2.jpg
http://antiqueradio.org/art/BROADCAST_NEWS_0656_3.jpg
http://antiqueradio.org/art/BROADCAST_NEWS_0656_4.jpg

I built one last year.

Phil Nelson
http://antiqueradio.org/index.html
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  #174  
Old 04-07-2011, 12:56 AM
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Quote:
Originally Posted by Tomcomm View Post
Newvista...........Here's a tube version of the RCA external input driver for the Roundies I got from Pete D. Hope you can use it..........Tom
Was just thinking your TV must have direct Vid (as well as an amazing CRT)

Thanks to you and others who posted details of this RCA Vid Input, I like the DC restoration & peaking coils.Will try building this one. Meanwhile I adapted another from the net to my CTC-5 that has a tuner problem (details on a separate post)
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  #175  
Old 04-08-2011, 04:02 PM
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External Video Input

Since my 21CT55 is not an original RCA restoration but a "laboratory test-bed", I saw no reason to copy RCA's external video input circuitry using early '50s technology. Instead, I implemented a solid-state video op-amp that provides a "perfect" DVD quality 480 line resolution, 75ohm , 5vpp signal into the 55's 1st video amp grid. It also supplies the same 75ohm video at 1vpp to my two comb-filtered Sony monitors and a Leader waveform monitor. Two external video sources can be selected with a toggle switch, each with individual level and offset controls. Presently I run a DVD player with the DVE test disk into one input and a second DVD player with program disks or OTA HD converter into the second input. Now that the 21CT55 's PQ is at least as good as it was before the tragic FBX meltdown I intend to resume my implementation of 480 line component video processing in addition to the present 280 line composite processing, hopefully.......Tom
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  #176  
Old 04-08-2011, 09:56 PM
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Quote:
Originally Posted by ChrisW6ATV View Post
Thanks for that diagram, Tom (and Pete). An "Official RCA" video input mod!
There will be a presentation at the ETF Convention covering both B&W and Color adapters. Wayne Abare describes his solid state adapter for B&W and I my modifications to the RCA 12AT7 circuit. Now all i need to do is write my half.


Pete
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  #177  
Old 04-17-2011, 06:33 PM
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Quote:
Originally Posted by Tomcomm View Post
Newvista...........Here's a tube version of the RCA external input driver for the Roundies I got from Pete D. Hope you can use it..........Tom
Thanks for this link and also for the Broadcast news links posted by Phil Nelson a few messages later.

I've built a few video adaptors for various color sets but all mine have been using basic transistors.

While they work well, they are certainly not as elegant as one using an IC.

Would you share your IC adaptor schematic with the list?
Regards,
Cliff

Last edited by cbenham; 04-17-2011 at 06:36 PM.
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  #178  
Old 04-18-2011, 12:18 PM
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IC Video Input

I use a Signetics NE5539 video op amp. It drives the 1st video amp grid with at least 3vpp and also the video monitors I use for all PQ comparisons.
Attached Images
File Type: jpg video input amp 2.jpg (99.2 KB, 56 views)
File Type: jpg 147-4733_IMG.jpg (118.5 KB, 151 views)
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  #179  
Old 04-18-2011, 12:46 PM
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You should replace those wax caps!
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  #180  
Old 04-21-2011, 12:18 PM
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Quote:
Originally Posted by Tomcomm View Post
I use a Signetics NE5539 video op amp. It drives the 1st video amp grid with at least 3vpp and also the video monitors I use for all PQ comparisons.
Thanks very much for the NE 5539 information and schematic. There are instances where as much as 8 volts pp are needed for some sets and also opposite polarity video at that same level, so I'll be breadboarding this to see how far I can push it.
Regards,
Cliff
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