UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Television Standards Converters, Modulators etc

Notices

Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions.

Closed Thread
 
Thread Tools
Old 4th Nov 2018, 8:21 pm   #1
clivemd
Triode
 
clivemd's Avatar
 
Join Date: Aug 2018
Location: Hertfordshire, UK.
Posts: 12
Default 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
Attached Thumbnails
Click image for larger version

Name:	20181104_130752373_iOS.jpg
Views:	711
Size:	65.2 KB
ID:	172165   Click image for larger version

Name:	20181104_130842286_iOS.jpg
Views:	617
Size:	101.6 KB
ID:	172166  
clivemd is offline  
Old 4th Nov 2018, 9:04 pm   #2
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,790
Default Re: Can you identify this?

https://www.radios-tv.co.uk/communit...translator-x2/

Nick.
Nickthedentist is offline  
Old 5th Nov 2018, 9:59 am   #3
clivemd
Triode
 
clivemd's Avatar
 
Join Date: Aug 2018
Location: Hertfordshire, UK.
Posts: 12
Default Re: Can you identify this?

Thanks Nick - perfect!
clivemd is offline  
Old 5th Nov 2018, 10:22 am   #4
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,790
Default 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
Nickthedentist is offline  
Old 5th Nov 2018, 5:33 pm   #5
clivemd
Triode
 
clivemd's Avatar
 
Join Date: Aug 2018
Location: Hertfordshire, UK.
Posts: 12
Default 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?
clivemd is offline  
Old 5th Nov 2018, 6:05 pm   #6
dazzlevision
Dekatron
 
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,586
Default Re: Can you identify this? (Rediffusion Frequency Translator).

Quote:
Originally Posted by clivemd View Post
I assume that (when working) these still make an entirely passable standards converter?
No, not a standards converter (if you mean converting a 625 video signal to the 405 line standard).

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.
dazzlevision is offline  
Old 6th Nov 2018, 7:24 am   #7
clivemd
Triode
 
clivemd's Avatar
 
Join Date: Aug 2018
Location: Hertfordshire, UK.
Posts: 12
Default 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.
clivemd is offline  
Old 6th Nov 2018, 9:45 am   #8
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,790
Default Re: Can you identify this? (Rediffusion Frequency Translator).

Jeffrey's added:
Quote:
This never was a standards converter. It was simply a modulator that
took a 405 line video signal and produced an RF output on Channel 1.

The original Rediffusion box was a UHF 625 line analogue receiver which
also contained a Rediffusion HF modulator. The box was made so that
Rediffusion customers could still use their TVs when the Rediffusion HF
wired service was discontinued. I modified the HF modulator to run on
Channel 1.

In 1989 there were no low cost standards converters available. Just a
few ex BBC and ITV converters for the few lucky people who had them or
optical (point a camera at a monitor) for everyone else. The first
affordable converters, the Dinosaur and the Pineapple, were made
available c1993.
Nick.
Nickthedentist is offline  
Old 8th Nov 2018, 2:27 am   #9
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,668
Default Re: Can you identify this? (Rediffusion Frequency Translator).

Quote:
Originally Posted by clivemd View Post
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.
In that case you may find my solution even more viable (and you won't need the Ferraro Roshay box)

https://www.youtube.com/watch?v=ahzdx4KgWBg
__________________
--
Graham.
G3ZVT
Graham G3ZVT is online now  
Old 9th Nov 2018, 2:14 pm   #10
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 5,803
Default 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.
dave walsh is offline  
Old 9th Nov 2018, 8:33 pm   #11
clivemd
Triode
 
clivemd's Avatar
 
Join Date: Aug 2018
Location: Hertfordshire, UK.
Posts: 12
Default 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?
clivemd is offline  
Old 13th Nov 2018, 4:37 pm   #12
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 5,803
Default 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.
dave walsh is offline  
Old 15th Nov 2018, 6:21 pm   #13
llama
Octode
 
llama's Avatar
 
Join Date: Jun 2006
Location: St Osyth, Nr Clacton, Essex, UK.
Posts: 1,481
Default 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
__________________
Half my stuff is junk - trouble is, I don't know which half!
llama is offline  
Old 15th Nov 2018, 10:27 pm   #14
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,668
Default 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.
Attached Thumbnails
Click image for larger version

Name:	Rediffusion.jpg
Views:	330
Size:	121.8 KB
ID:	172880  
__________________
--
Graham.
G3ZVT
Graham G3ZVT is online now  
Old 17th Nov 2018, 9:30 pm   #15
Freya
Octode
 
Freya's Avatar
 
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
Posts: 1,981
Default 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
__________________
Stephen
_________"It`s only an old telly" ___
Freya is offline  
Old 17th Nov 2018, 11:38 pm   #16
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 5,803
Default 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.
dave walsh is offline  
Old 6th Mar 2019, 5:16 am   #17
Restoration73
Nonode
 
Restoration73's Avatar
 
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
Posts: 2,801
Default 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.
Restoration73 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 5:07 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.