10th Dec 2018, 2:46 pm | #21 | |
Dekatron
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Re: CRT is brighter to one side
Quote:
My 1978 ITT with ultrasonic remote also has this design.
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10th Dec 2018, 6:23 pm | #22 | |
Octode
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Re: CRT is brighter to one side
Quote:
I just googled the AVS2000, and sure enough I would love one! Can't say I've ever seen something like it. |
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11th Dec 2018, 2:57 pm | #23 |
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Re: CRT is brighter to one side
Fidelity AVS2000. Don't. Just don't.
The flying on-off button was a Rediffusion/Doric Mk4, early to mid - Eighties. It was also badged Murphy as Ben says, though I haven't seen a Fidelity version. Though we were Hitachi dealers, I've never seen a remote control like that one. This is a pre-Instavision set so once you've located and replaced the faulty capacitor the CRT should be as good as new - and it will be a reliable set. Post a picture of the chassis so we know what we're dealing with. |
11th Dec 2018, 7:28 pm | #24 |
Octode
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Re: CRT is brighter to one side
I think I'm picking up the TV Friday now, but I'll post a picture of the chassis ASAP.
Thanks |
12th Dec 2018, 11:22 am | #25 | |
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Re: CRT is brighter to one side
Quote:
Peter |
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12th Dec 2018, 11:46 am | #26 |
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Re: CRT is brighter to one side
That was said with feeling, I heard that this model had its problems.
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Frank |
12th Dec 2018, 9:26 pm | #27 |
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Re: CRT is brighter to one side
One post moved to a new thread: https://www.vintage-radio.net/forum/...d.php?t=152258
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12th Dec 2018, 9:49 pm | #28 |
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Re: CRT is brighter to one side
Post Philips, my mate and I sold a fair few of those. He bought a job-lot... basically catalogue returns that couldn't be fixed by their 'electrician'. Most of them had power supply and line stage faults. They were fine as long as they didn't go wrong again......
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12th Dec 2018, 10:29 pm | #29 |
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Re: CRT is brighter to one side
My gran had a TV with an ultrasonic remote years ago, took a while to sus out why the dogs went nuts every time the channel was changed! LOL. M3VUV.
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12th Dec 2018, 11:10 pm | #30 |
Octode
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Re: CRT is brighter to one side
Why is that? Someone else said about budgies did it too.
Doesn't ultrasonic emit some kind of sound humans can't hear? I could be wrong on that. Thanks |
12th Dec 2018, 11:18 pm | #31 | |
Dekatron
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Re: CRT is brighter to one side
Quote:
The more modern type of remote does not use sound, but uses infra red emission (infra: below). So, that is below the frequency of visible 'red light'
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12th Dec 2018, 11:38 pm | #32 |
Octode
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Re: CRT is brighter to one side
Thought it was, just wasn't 100% sure.
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13th Dec 2018, 12:59 am | #33 |
Nonode
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Re: CRT is brighter to one side
Hi.
That's possibly a CVC32 (22"), CVC30 (26") chassis using the 20AX CRT or the less common CVC25 (22") chassis using the Hitachi CRT. The remote control plugged into the front of the set and could still operate the set with the ultrasonic transducer isolated. There was a 3-way connector in the remote to connect to the TV. I liked those vertical chassis modular ITT sets. The various modules could be plugged in on the print side of the motherboard so were great sets for servicing. The most common faults I experienced were either the tripler or occasional LOPT failure causing the TDA2640 based power supply to trip. Dry solder joints were common mainly in the line output stage and that burn up on the scan correction board Pressac connector that carries the line scan current. There was also a safety issue with some of the mains switches, not so much about the switch itself, rather the embrittled solder joints. The recommended solution was to solder four mains lead wires to the switch to bypass the print foil connections for a more safe arrangement. I'd like to find a CVC30 or CVC32 for my collection. Regards Symon |
13th Dec 2018, 1:13 am | #34 |
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Re: CRT is brighter to one side
Symon,
I have the 1922u and the larger 3620. They both use that plug-in remote. I am still looking out for the plug-in game of 'pong'! I think I had to change the tripler (or was it the line o/p tranny?) in one set.
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13th Dec 2018, 9:59 am | #35 |
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Re: CRT is brighter to one side
I did like the ITT range of TV’s and remember the plug in remote controls. I did not know about the plugin ping pong game, was it sold in the U.K.? We got the ITT agency in the middle 70’s when we were unhappy with Pye and RBM products, we still had those brands in the shop but many preferred the styling of the ITT sets and that suited us.
Faults, not many but triplers, line whistle from inductors, I think they recommended PVA glue but could be wrong, and frame output transistors. Did the remote use a PP3 battery, I seem to recall replacing the connections after damage by customers trying to change the battery.
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Frank |
13th Dec 2018, 12:56 pm | #36 |
Hexode
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Re: CRT is brighter to one side
I repaired many Hitachi telly's in my time, loved em.
As others have pointed out it will be an electrolytic, usually 4.7 or 10uF and usually on the tube base. When they dry out they don't store the energy to keep a constant voltage to the video output transistors and as the line scan progresses across the screen the voltage increases. |
13th Dec 2018, 7:54 pm | #37 |
Nonode
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Re: CRT is brighter to one side
Hi.
Ben, that's interesting to see the Pong game for the ITT and I was also unaware about that. Thanks for the pics. Frank, yes, the line whistles (magnetostriction) in the coil ferrites, was a common problem and again yes, PVA glue was recommended namely Resin W by Evo-Stik. I remember coming across various sets that had been in the hands of cowboys and in one set, the singing coil being silenced by a hewn block of wood wedged between the chassis and the offending coil. An effective bodge Regards Symon. |
13th Dec 2018, 11:25 pm | #38 |
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Re: CRT is brighter to one side
I believe that the ultrasonic frequencies of some of the early TV remotes lie in the range used by bats. There was a letter in I think the "New Scientist" in that era from a reader who noticed that a moth took rapid evasive action when he changed channel, and found that using the remote to tease moths was often more interesting than watching the then-current offerings on TV!
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14th Dec 2018, 10:50 am | #39 |
Nonode
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Re: CRT is brighter to one side
I can remember those ultra sonic remote controls on various TV's. We would get call outs for random channel changing caused by dry door hinges, rattling car or house keys and metal dog collars.
We use to do a mod on the early Thorn 9000 that desensitised the ultrasonic receiver in the telly that prevented this random pick up but had little effect on the range of the remote control.
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14th Dec 2018, 11:58 am | #40 |
Octode
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Re: CRT is brighter to one side
I picked the TV up and got it home. By the time I had got home it was too late to take things apart so I put the TV on a stand and played my Atari on it for a while.
I have 1 new issue with it, and the picture is wonky, the right side of the image is higher than the left side. I tried the convergence knob at the back, but that only moves the image left and right. How do I fix this? I'm also just about to open up the back to take photos to show on here so we can see what we're working with. Is there anything I need to know before hand? I've unplugged the TV from the mains, so it has no power supply but could there be anything else to be careful with? I just want to be as careful as possible as I've very little knowledge of CRT's at the moment. Thanks |