#1
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Wanting to tap the rgb port
Hello,
First time poster here. I was referred from the Facebook group the CRT Collective. It's a 1989 Zenith System 3 Digital. I bought this tv from a fellow member there and it has an rgb port on back. I was wondering if anyone knew how or what is needed to use it. I'll include some pics. Any help appreciated Thanks! |
#2
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I'd assume it'd be for connecting one of them new-fangled 'personal computors,' especially since the next one over says Text Print. But it's quite odd that it's a card edge connector. I'd imagine it uses a fairly standard VGA style signal, but I have no idea. Look up at the connector from the bottom and see how many pins it has. I'd wager 10.
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#3
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Sweet set! Love the lighted keypad. A service manual should have the info you need.
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#4
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Any clue where I could find one of those manuals?
I was hoping to see what all the rgb hype was all about. I have a snes I was wanting to hook up. I'll try and get a closer look and see how many pins there are. Also I aplolgize, I did not realize the pictures posted in the orientation they did. |
#5
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Even though it's a digital TV, I'm sure it's an analog input. Zenith was big into PCs at the time and had a proprietary cable to plug in.
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Audiokarma |
#6
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I'm guessing that the text print port means that this set has a Teletext decoder.
I can't recall what the RGB port would be on these. There's a good possibility it's not compatible with anything current; for example, it could be TTL logic levels. Maybe somebody who knows for sure will chime in. |
#7
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Quote:
He was the biggest toy and trinket buyer, I ever knew! |
#8
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Wow yours still has a sweet pix. When they came out the table
model was $1100 & we sold it $1000 with a free printer. Teletext was just a newspaper format & also used by truckers to find loads. It was sent by the Atlanta superstation on cable. The set was NTSC. After video & audio detect everything was digitally processed then back to analog for the outputs. I dont remember the RGB but probably TTL. Look for an owners manual, OEM service manual, training manual or Tech Topics for more on it. One thing I would do to this set is recap ( lytics only) the vert board. A bad cap will blow the IC. The IC has been disco for YEARS......... 73 Zeno LFOD ! |
#9
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...
Last edited by andy; 11-18-2021 at 05:03 PM. |
#10
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Quote:
While my set has the teletext option in the OSD menu, however, I am not sure if the decoder would have been usable since there are no RGB or printer ports on the back of the set; the only input jack there is a 75-ohm connector for antenna or cable TV. Since the set has no RGB or printer ports, I can't help but wonder why the TV had a teletext decoder in the first place, unless it was designed only for on-screen readout, the RGB/printer ports were available as extra-cost options, or if there was a special model of this TV that indeed had the ports built in.
__________________
Jeff, WB8NHV Collecting, restoring and enjoying vintage Zenith radios since 2002 Zenith. Gone, but not forgotten. |
Audiokarma |
#11
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Thank you all so much for the responses. Looks like there are 7 pins on that edge connector from what I can see. I will also certainly look into a recap, don't want anything happening to this ole thing. It seems to work well. Not sure how hard or how much it was used. But I'm pry correct in assuming this was zenith top end back in that time, yes?
Last edited by madMatador78; 12-23-2017 at 12:42 PM. |
#12
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Teletext use was expected to mainly be on-screen, with printing used infrequently, much like a modern internet service. In Chicago, where Zenith was located, the service from Atlanta was broadcast. For a while, there was a long-haul trucking jobs listing service, and it was intended that teletext receivers would be installed at major truck stops so independent truckers could bid/apply for runs (I'm not sure exactly how it worked). Another service was intended for home use and had things like news summaries, horoscopes, recipe of the day, and so on. I had a Zenith rear projo with Teletext at home, and would call the service sometimes to request a particular recipe to be posted, or answer the day's puzzle. The broadcasts in Chicago also contained test pages of repeating characters that made the clock recovery particularly difficult. One of these was titled something like "Page for Gary." Gary was an engineer at Zenith working on Teletext. The page stayed up long after the attempts at commercial service died, until Teletext was removed entirely.
PS: Teletext coding was at a low data rate, intended to be relatively ghost-resistant without requiring a ghost correction circuit in the receiver. |
#13
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Quote:
IIRC the digital chip set was made by ITT. I have seen it used. also in Toshiba, & NEC sets. Also probably was in MGA & Panasonic but I have only seen the manuals. Zenith by far built the most of them. It came in 19" or 20" ( dont remember which ) 27" & projo's. Also some had Bose audio & there was an amp only option. Awsome sound ! Yup it was WTBS that carried text. Zenith also owned a Chicago UHF but I would guess that was sold off years before. JEFFHS. Your set is interesting. The model hints at it being an institutional set. Also 19" was rare then. If you ever can we would LOVE to see some pixs of it & nudies. 73 Zeno LFOD ! |
#14
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Edit: Starting separate thread
Last edited by dibmem; 12-27-2017 at 08:03 AM. Reason: Starting separate thread |
#15
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Edit: Starting separate thread
Last edited by dibmem; 12-27-2017 at 08:02 AM. Reason: Starting separate thread |
Audiokarma |
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