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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 Jan 2013, 7:13 pm | #21 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
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Re: Building Darius converter - some parts NLA
Hi Mikey.
You can indeed use two 74HCT40103s in place of a 74HCT4059 for the divide by 283 function. Darius did this in his Mk1 converter, see Blatt 10 dated 26/12/04. I can't seem to find Darius's website at the moment for reference to his circuit. See also Peter Scott's modified circuit here: http://www.scottpeter.pwp.blueyonder.../newscheme.jpg RS Components stock the 74HCT40103 counter ics under part no. 652-279. Regards Symon. Last edited by Philips210; 4th Jan 2013 at 7:14 pm. Reason: text |
4th Jan 2013, 8:04 pm | #22 |
Triode
Join Date: Sep 2005
Location: Hemel Hempstead, Hertfordshire, UK.
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Re: Building Darius converter - some parts NLA
Hi Symon,
Thats an interesting mod by Peter Scott, thanks. I have just recieved the CXL's from JH comps, i'm impressed. I guess I now need to look at the various design variations and consider the overall construction details & whether its worth doing a new PCB layout or start a pin/wire prototype. Some components are surface mount & im used to doing quick PCB prototyping. Regards. Mike |
4th Jan 2013, 8:36 pm | #23 |
Triode
Join Date: Sep 2005
Location: Hemel Hempstead, Hertfordshire, UK.
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Re: Building Darius converter - some parts NLA
Further to my prevoius post I have come across the following site:-
http://normwandler.blogspot.co.uk/20...einfhrung.html I believe it's Darius's blog & has the MK I cct diags |
4th Jan 2013, 9:25 pm | #24 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
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Re: Building Darius converter - some parts NLA
Thanks Mikey for the link.
I had been trying, without success, to access Darius's original website, where he had the circuits for the Mk1 version. Regards Symon. |
4th Jan 2013, 9:35 pm | #25 | |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
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Re: Building Darius converter - some parts NLA
Quote:
Regards Symon. |
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5th Jan 2013, 12:40 am | #26 |
Dekatron
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Re: Building Darius converter - some parts NLA
I remember having to make something like that once, in order to use ICs that were only available as SMDs with copper strip breadboard. I did it by soldering fine lengths of bare wire to each lead of a surface-mount SOIC, and then soldering the wires to the receptacles of a normal-sized IC socket.
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26th Jan 2013, 1:19 pm | #27 |
Dekatron
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Location: Gateshead, Tyne and Wear, UK.
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Re: Building Darius converter - some parts NLA
I've finally reassembled my converter and installed it into the cabinet that was bought for it in 1984. There are still few minor jobs to to do to it.
This is the version I built in 1990 and has only one line interpolator. A year later an improved version was made with two line interpolation. I intend to do a reconstruction of the two line IPL converter but it will have be much later in the year. Too many other tasks to do at present. The TV set is the Marconi VT161. DFWB. |
16th Feb 2013, 1:21 pm | #28 |
Triode
Join Date: Sep 2005
Location: Hemel Hempstead, Hertfordshire, UK.
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Re: Building Darius converter - some parts NLA
Hi Symon,
Have been away from this for a few weeks so trying to catch up on this thread. I am now attempting to do a layout of the CCD board of Darius's converter. It Will probably be a pin & wire construction on tinned matrix board you can get from Farnell or RS. In post #8 you have a picture of the board but the image is a bit blurred. I would be grateful for a clearer version so I can use the component labels to get the layout similar. Regards. Mike |
16th Feb 2013, 1:51 pm | #29 |
Moderator
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Re: Building Darius converter - some parts NLA
A standards converter could be done as a programming exercise with a large-ish programmable gate array. There's certainly enough fast RAM in many of them for a full frame store for both incoming and outgoing standards, and pseudo-ROM for a few test-cards.
An interesting project for a final year student? David
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16th Feb 2013, 10:24 pm | #30 |
Nonode
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Re: Building Darius converter - some parts NLA
Hi Mikey.
I've taken a couple of pics of the CCD board. There is also the component overlay diagram and a pic of the blank PCB before assembly which should be helpful. Note the CXL5508M ics in pic3. I did notice an error on the blank PCB, C27 and C29 are transposed, though that won't be important if you're only using it as a general guide as you'll be using the circuit diagram circuit diagram for reference. C27 and C29 are correctly marked on the overlay diagram. If the overlay is not quite clear enough, then I can send you my original, just send me a PM if necessary. One thing worth mentioning, get the A4 circuit diagrams blown up to A3, you'll be glad you did as it makes it much easier to follow, and saves on eye strain. I connected the CCD and clock boards with 0.1" connectors but there is little room on the boards for these. In some cases, I soldered extension connectors to the board mounted connector so the socket cleared the components. Obviously, if you're doing your own layout then it's worth giving yourself plenty of space for any connectors. Personally I wouldn't mind the circuit occupying say three times the area so that it's easier for servicing. If you need any more pics and for the Clock board then let me know. I have taken many pics of the various waveforms on the scope and noted all transistor voltages in case of future problems. Regards Symon |
17th Feb 2013, 12:08 am | #31 |
Triode
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Location: Hemel Hempstead, Hertfordshire, UK.
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Re: Building Darius converter - some parts NLA
Hi Symon,
Many thanks for the details of the board layout. I agree that it could be made on a bigger scale. I will do this but keep the relative component positions about the same. If I have a ground plane then it should not be that critical. Regards. Mike |
5th May 2016, 11:22 pm | #32 |
Nonode
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Location: Redruth, Cornwall, UK.
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Re: Building Darius converter - some parts NLA
Hi
I wonder how Mike got on with his standards converter? Regards Symon. |
26th Jul 2016, 9:15 pm | #33 |
Triode
Join Date: Sep 2005
Location: Hemel Hempstead, Hertfordshire, UK.
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Re: Building Darius converter - some parts NLA
Hi Symon,
Its been a while since I logged onto this forum and posted. I did make a start with Darius's analogue converter. I have a PCB CAD layout tool and produced Gerber artwork for the analogue and timing boards. Unfortunately the project has stalled for a couple of years for various reasons including moving home. However I do intend to start it up soon along with a couple of TV restoration projects waiting in the queue of jobs to be done. Hopefully I will bev able to post some progress sometime soon. Regards. Mike |
27th Jul 2016, 9:30 pm | #34 | |
Dekatron
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Re: Building Darius converter - some parts NLA
Quote:
Peter Last edited by AC/HL; 27th Jul 2016 at 11:13 pm. Reason: Image uploaded |
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