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Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions. |
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4th Nov 2018, 8:21 pm | #1 |
Triode
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Can you identify this? (Rediffusion Frequency Translator).
All,
Further to the examination of my late fathers shed contents, can anyone identify this? I am guessing it is a standards converter of some sort... Thanks, Clive |
4th Nov 2018, 9:04 pm | #2 |
Dekatron
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Re: Can you identify this?
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5th Nov 2018, 9:59 am | #3 |
Triode
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Re: Can you identify this?
Thanks Nick - perfect!
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5th Nov 2018, 10:22 am | #4 |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
My friend Jeffrey Borinsky's been in touch and thinks that it might have been modified as per his 1989 article here: http://www.borinsky.plus.com/simple_channel.html
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5th Nov 2018, 5:33 pm | #5 |
Triode
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Re: Can you identify this? (Rediffusion Frequency Translator).
That's entirely possible Nick given the date of the article. I assume that (when working) these still make an entirely passable standards converter?
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5th Nov 2018, 6:05 pm | #6 | |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
Quote:
The conversion by Jeffrey Borinsky produces a Channel 1 System A (405 lines VHF, 3MHz vision to sound carrier spacing) modulator, so that a standard domestic 405/VHF TV can receive it on Channel 1. You'd still need a 405 line composite (baseband) video source to feed into the modulator. |
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6th Nov 2018, 7:24 am | #7 |
Triode
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Re: Can you identify this? (Rediffusion Frequency Translator).
I vaguely remember some talk of 405 line video tapes and this unit is connected to a chunky old Ferguson VCR so that sounds like a viable scenario.
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6th Nov 2018, 9:45 am | #8 | |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
Jeffrey's added:
Quote:
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8th Nov 2018, 2:27 am | #9 | |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
Quote:
https://www.youtube.com/watch?v=ahzdx4KgWBg
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9th Nov 2018, 2:14 pm | #10 |
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Re: Can you identify this? (Rediffusion Frequency Translator).
These boxes were around in Ramsbottom when CH4 appeared-never seen one since. The broadcast relay at Grants Tower couldn't accommodate an extra channel from Winter Hill. Homes with the Redifussion Cable Service [I'd guestimate half to a third by then] could indeed get the new channel via a translator box that overcame the problem but it was a £50 purchase-quite a lot circa 1982!
I had a cable connection to my house but had never been a customer. Despite a lot of criticism at the time for it's experimental content, the new Channel showed films such as Abel Gance's Napoleon and Dylan's Renaldo and Clara [that one two weeks after sending me a letter saying they had "no plans to Broadcast it in the near future"]. My solution wasn't very technical. I simply drove to my brothers house in Bury and recorded programs onto my Video Recorder there. I recall spending a Saturday afternoon hanging out of my attic window with an 18 element aerial and obtaining just the occasional faint image of the B+W Gance classic. Sadly, Holcombe Hill was a barrier to receiving the Winter Hill Transmissions [directly] no matter what I tried! That's indeed why Rammy became a cable pioneer in the fifties [like Bexhill]. Nobody seems to notice but quite a few of those much derided "way out" CH4 ideas still turn up within adverts today. A recent Ch5 program pointed out that Winter Hill is riddled with underground shafts and passages which surprised me. Did they know about that when the mast was erected I wonder? Dave W Last edited by dave walsh; 9th Nov 2018 at 2:19 pm. |
9th Nov 2018, 8:33 pm | #11 |
Triode
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Re: Can you identify this? (Rediffusion Frequency Translator).
Loving all the great info! What I guess I've ended up on-clear on is if it's really potentially any use? I understand what it's doing, but am feeling that things have evolved since the modification was designed and it's not really relevant any more?
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13th Nov 2018, 4:37 pm | #12 |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
I think it depends what you mean by relevant Clive. I'm sure 405 line enthusiasts would be interested! I've got a Rediffusion set [courtesy of Mike Barker] who brought it up to a previous Golborne Meet for me and in the Ramsbottom context, it will be a talking point even if its never up and running! Visitors are asked to guess what's missing on the basis that it's pre the era of a remote control but it [usually] has to be pointed out that there is no channel selector on the set.
I've a PTV mag that illustrates the Rediffusion universal chassis and various options eg when these wired sets were installed in hotels etc. It was also possible to add a tuner front end in some circumstances. I'm talking more the 625 line era now though! As Nick outlined via Jeffries further explanation [in post 8] and my comments, it was the only way of receiving a fourth channel in Rammy for a long time. We were probably the last place in the country to get a Relay upgrade! It was very unfair really. Even existing subscribers had to lay out 50 notes as only those at the western end of the valley could pick up Winter Hill and four channels. The rest of us had just the "big three" on our aerials from the Relay. I enjoyed the video demo from Graham [Rambo] you're a natural presenter! although I wouldn't claim to grasp the conversion theory, whatever the method. It does seem "neat" [as the Americans say rather than using big words like sophisticated or clever] despite the chocolate box case! I suppose the commercial units may provide lots more plug in and play options, especially for the solid state and computer dim like myself. Dave W Last edited by dave walsh; 13th Nov 2018 at 5:03 pm. |
15th Nov 2018, 6:21 pm | #13 |
Octode
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Re: Can you identify this? (Rediffusion Frequency Translator).
Clive, it might be most use restored back to its original use. A couple of years ago one of our members was the proud owner of an original tuner-less Rediffusion TV but had no way of getting any sort of signal into it. I had a spare unit like yours but in original condition so he had that off me and, I presume, was then able to input RF (or with a small mod, baseband video) so the set could work as expected.
Graham
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15th Nov 2018, 10:27 pm | #14 |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
Here, just for completeness is the exact opposite of what you have there before it was modified.
It took the HF video and base-band audio from the switch on the wall or windowsill, demodulated the video then re-modulated it onto a UHF carrier so a normal TV could be used. You can see the ubiquitous modulator can that was in most VHS machines back in the day. I have at some point "borrowed" some components including the chip. It fitted into a box identical to the Labgear Televerta, so that may be a clue to its maker, it only had a Granada stock-category label on it.
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17th Nov 2018, 9:30 pm | #15 |
Octode
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Re: Can you identify this? (Rediffusion Frequency Translator).
found this link that shows how they are modified; scroll down to modulator conversion.
https://www.bvws.org.uk/405alive/tech/modulator.html
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17th Nov 2018, 11:38 pm | #16 |
Dekatron
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Re: Can you identify this? (Rediffusion Frequency Translator).
Thanks Rambo and Freya that's exactly what I was talking about. I think the multi strand cable to the wall switch carried signals at SW ie 9 Megs or so but I may be wrong about that. I sent my switch to Dave Moll years ago and received some money I hadn't asked for. That's the Forum for you, he wouldn't take it back. Apart from Rammy and Bexhill [Hastings Cable Service] my brother in law lives in Shoreham. There seemed to be a lot going on there as well. The proximity of French 819 broadcasts was an ongoing second "Channel" problem I gather.. especially in the summer heat
Dave W Last edited by dave walsh; 17th Nov 2018 at 11:47 pm. |
6th Mar 2019, 5:16 am | #17 |
Nonode
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Re: Can you identify this? (Rediffusion Frequency Translator).
Display Electronics sold the modified box with the phono sockets and front mounted volume control as the "Telebox" and it would appear these came from storage where there had been some minor flooding although that seemed to be dried out.
I have a couple of small standalone Rediffusion modulators where the dc is derived from the mains via a capacitor-rectifier with zener circuit, i.e. no mains transformer. |