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#1
08-17-2022, 03:12 PM
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Heathkit GR-2000 Sold State Color TV
Another TV I recently added to my collection this summer. It is a Heathkit GR-2000 solid state color TV. I picked this tv up for free from a home that was being cleaned out. From what research I have done on this tv. This tv was sold as a kit for people to build starting in 1973 until at least 1976. My particular tv was already built by the previous owner in the early 1980s according to his daughter. The tv parts are all dated at various months in 1976 so it was likely that this tv kit was not built until a few years after purchase.
It appears to be a low hour set. All caps tested good using my Capacitor wizard. I recapped some anyways since I had extra low voltage ones and that went well. The issue with this tv appears minor and related to loose cold solder joints where the coaxial and antenna hookups go on the back of the tv. It may possibly also need some adjustments to the convergence. TV is very advanced for its age. All transistorized including the HV stuff. TV has LOTS of IC chips, digital channel display and a clock board to show the time! TV is in great shape aside from a few scuffs on the handmade wooden cabinet which has metal roller caster wheels on it. I knew of Heathkit but never knew they offered TV kits. I am very impressed by the design and the ease of which I can service the boards if need be. CRT appears to be fine when turned on. Will post more updates as I work on it. https://imgur.com/a/JLTZlPO 
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#2
08-17-2022, 07:06 PM
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A follow up to my first post, I am able to get a picture on the tv from my VCR via RF out channel 4 but the convergence appears to be off fore some reason, along with the horizontal having some issues at the top of the screen. Vertical hold though is ok. Here are some photos showing the issue. Not sure if the CRT directly needs adjustment or if it is an issue with the tuning circuit/board due to drifting values of carbon comp resistors.
I turned on dot mode for the last few pictures to show the convergence issue more clearly. https://imgur.com/a/k8WogaA
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#3
08-17-2022, 07:46 PM
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That looks a lot like a Zenith with HealthKit additions. The first heath kits were rca’s with a crosshatch generator added. I built a HealthKit black and white set back around 1965.
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2 Working Zeniths and one on the bench. Into electronics since the days of Earl "Madman" Muntz..Worked 8 years for a Zenith dealer in NW Arkansas.
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#4
08-17-2022, 08:31 PM
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I just saw your Imgur posts regarding your Heathkit GR-2000. However, I wonder why the picture which, in at least one upload, seems to have a bend in it, similar to the bend caused by defective filter caps in older TVs which causes 60Hz AC to get into the sweep system. Is there any hum in the sound as well?
Aside from the CRT, I don't think this TV has any other tubes, so the problem, if there is one, would almost have to be caused by defective filter caps in the power supply. The GR-2000 is 100 percent solid state, so heater-cathode shorts in tubes cannot cause hum anywhere in the set. The only other thing I can think of, however, which could cause a bend in the picture would be the auto degaussing coil, which may not be shutting off completely when the TV is powered on. Normally, the degaussing coils will operate for a few seconds at most; the coils will have been shut off by the time the TV picture appears on the screen.
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Jeff, WB8NHV Collecting, restoring and enjoying vintage Zenith radios since 2002 Zenith. Gone, but not forgotten.
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#5
08-17-2022, 09:36 PM
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Not a Zenith design. Zenith bought Heath in 1979. There were some later Heathkits based on Zenith chassis, I believe, but they involved much less construction and soldering and were more snap-together if I recall correctly.
The fact that the dot pattern is straight shows that this is not a power supply hum problem. It is probably a reaction to the VCR signal horizontal jump at the head switching time. Either something has failed in the horizontal AFC or more likely this set has an earlier design of the horizontal AFC filter section that predated VCRs. Another possibility is that there is a switch setting for a shorter AFC time constant, although I don't recall if there was one on the Heathkit I built in 1975. Play a DVD or digital converter box into the set instead of the VCR and verify that the wave goes away.
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#6
08-17-2022, 09:42 PM
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The other thing that indicates this is a VCR signal vs/ AFC problem is that the offset is worst at the top and decays towards the bottom. A power supply hum would be constant amplitude and slowly drift vertically.
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#7
08-17-2022, 11:58 PM
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Quote:
https://imgur.com/a/IrdSRJU
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#8
08-18-2022, 07:21 AM
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I've got a 2000 and it does that too. Its caused by the motorola chip that doesn't like the non RS170 sync coming from a vcr.
There was a motorola publication out to address the issue. A number of manufacturers used that chip. Now, I've converted my 2000 to composite video input. Easy modification!
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#9
08-18-2022, 08:49 AM
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This is one of the RCA clones with SCR Hoz sweep.
Later they did sell Zenith with the System 3 chassis. Convergence is easy. TIP turn color off & brite & contrast about half way. In other words dont drive it hard. If its just the top give the top controls a little bump first to see if one has a bad spot. Also watch for cold PC on the board, it gets hot there ! 73 Zeno  LFOD !
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#10
08-18-2022, 10:24 AM
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Quote:
Some other things, like the pre-aligned and potted IF filter are unique to Heath. This is a precursor to later TVS (including Zenith) that used SWIFs (Surface Wave IF).
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#11
08-18-2022, 11:36 AM
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Yes it does have SCR output but the oscillator chip is a MC1391.
Attached is the video input mod for the 2000. I used a Maxim MAX405 video op amp which might be a little hard to find these days. The video goes in at the emitter of Q326. (Q326 is removed.) I'm sure Linear Technologies makes a similar chip.
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Last edited by kf4rca; 08-18-2022 at 11:41 AM.
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#12
08-19-2022, 09:04 PM
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#13
08-19-2022, 09:20 PM
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this is completely unrelated to the thread topic, but for some odd reason
 the name "Lain" scares the crap out of me~  does the term " Accela " mean anything to you? :O
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#14
08-20-2022, 02:29 AM
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#15
08-25-2022, 11:14 PM
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and I laughed at people when it came out "pro" dub in the states years later and they would say "THEY RIPPED OFF THE MATRIX!" and I would tell them NO, the Matrix ripped of LAIN! :P
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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