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Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions. |
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15th Aug 2008, 10:20 pm | #21 | |
Octode
Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
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Re: Latest converter project
Quote:
Darryl has effectively set a new lower price for basic converters by using contemporary technology and a lot of ingenuity. I don't currently have any use for a more advanced model, but for what it does it is superb value for money at that price !
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Chris |
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16th Aug 2008, 3:27 pm | #22 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
Thanks for the feedback guys. I was concerned that I had taken this in the wrong direction now that it was finished and I was getting quotes back. It will probably be another week for everything to get solidified, and then a few weeks after that to get some units built.
Darryl |
16th Aug 2008, 4:43 pm | #23 |
Dekatron
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
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Re: Latest converter project
Might need to start a piggy bank......
Lots of possibilities for collecting with one of these! Cheers Sean
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Engineers make things work and have spare bits when finished |
16th Aug 2008, 6:22 pm | #24 |
Octode
Join Date: Nov 2004
Location: Hebden Bridge, West Yorkshire, UK.
Posts: 1,885
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Re: Latest converter project
Me too,
Will there still be a market for the original Auroras 2nd hand now or will everyone want one of these. Dom |
16th Aug 2008, 6:50 pm | #25 | |
Octode
Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
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Re: Latest converter project
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IMHO, the price differential between it and the new model will mean demand will still be high - People have, and will probably continue to buy more than one !
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Chris |
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16th Aug 2008, 7:18 pm | #26 |
Retired Dormant Member
Join Date: Oct 2007
Location: Leicester, UK.
Posts: 809
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Re: Latest converter project
I would think so, as some of us want more than one converter anyway .. that way we can use our old TVs as originally intended in my case, having BBC-1, ITV and a feed from a satellite receiver .. the latest converter will allow experimentation with various standards and will be able to provide 405-line signals from PAL and NTSC sources.
BG >EDIT< Forgot to refresh before posting! |
17th Aug 2008, 6:01 am | #27 | |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
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Darryl |
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17th Aug 2008, 9:39 pm | #28 |
Retired Dormant Member
Join Date: Mar 2005
Location: Braunschweig, Germany
Posts: 208
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Re: Latest converter project
Hi Darryl,
if things work out, I will get an old Sovjet KVN-49 tv set for the Sovjet television standard. Would this converter also provide an antenna signal for this tv set? Kind regards, Eckhard |
17th Aug 2008, 9:58 pm | #29 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
Hi Eckhard,
My books show Russia using System D on VHF and System K on UHF. If this is correct, the unit does have these systems coded in. The complete list of systems currently coded are: A, B1, B2, B3, B4, B5, B6, C, E, F, G1, G2, H, I, K, L, M1, M2, N, and seven pre-war experimental systems. All defined channels for each of these systems is coded for a total of over 500 channels. If my information is wrong about the RF System Russia used, please let me know. Take care, Darryl |
21st Aug 2008, 1:12 am | #30 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
I've posted a first draft manual for the new converter at:
http://converter.home.comcast.net/~c...Manual_1.0.pdf Please have a look and let me know if it is detailed enough, or not detailed enough, or whatever other comments you might have. Thanks, Darryl |
21st Aug 2008, 9:55 pm | #31 |
Hexode
Join Date: Jan 2005
Location: Waterford, Republic of Ireland
Posts: 259
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Re: Latest converter project
Hi Darryl,
Put me down for one when they are available! Would there be any chance you could add a few channels for the Ham TV bands -70 cm and maybe even FM on the 23cm band, also usable for 'vintage analogue satellite receivers, (don't forget Europe's band is quite a bit narrower than the USA) Would VSB be feasiible using I and Q synthesis? It might encourage a bit more vintage TV over the ether! Andy EI3HG |
21st Aug 2008, 10:45 pm | #32 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
Hi Andy,
Since I have a microcontroller on this design, I took a different approach and completely split the system control out of the fpga. This makes the fpga just a data processing engine. All variables describing the standards and RF channels reside in the microcontroller. The intent was to make the design flexible enough that adding standards or RF channels would be very easy, and possibly done by the user. The downside for a user adding a standard definition is there are over 200 registers in the fpga that need to be calculated, many with nasty stuff like filter coefficients. On the RF side things are much more straight forward, and it should be a simply matter to allow users to create their own RF System. Call it a system "U". I'll need to come up with a clean way for the user to enter the data, but all the pieces are there. I briefly considered a side band filter for this design, but it would have been complicated and costly. I think once we are forced to move on from these Freescale modulators, as they have gone end-of-life, it would make sense to rethink the modulator from the ground up, and anything might be possible. Take care, Darryl |
24th Aug 2008, 10:59 am | #33 | |
Dekatron
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
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Re: Latest converter project
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I notice you don't have NZ channels 10 and 11 - I know they're not really vintage but if its not difficult you may as well include them for completeness. Channel 10 must have come into use sometime mid-late 70's (a 1973 B&W set I have doesn't have it, but a 1982 colour does). Not sure on channel 11, but TV4 used it at launch over much of the country in 1997. |
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24th Aug 2008, 1:37 pm | #34 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
Hi arjoll,
Thanks for the correction. I looked through all my references and could not find the carriers for channels 10 and 11, but doing a quick internet search found them. I also found that at some point the frequencies from channel 6 up were move lower, presumably to make room for 10 or 11. I have the table updated now. Thanks, Darryl |
24th Aug 2008, 6:58 pm | #35 |
Retired Dormant Member
Join Date: Oct 2007
Location: Leicester, UK.
Posts: 809
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Re: Latest converter project
I had a look at the manual and think you've done an excellent job.
I would like to suggest that the table of supported RF Systems include the line system, whether positive/negative modulation and audio carrier/system - would make a great cross-reference for us! Many thanks Brian |
25th Aug 2008, 4:24 am | #36 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
I did a major update of the code and manual over the weekend. I added the video and audio modulation types to the table at the back of the manual as Brian suggested. I didn't add the line system as there is nothing precluding the user from sending any output standard out any RF System. I default to the correct one, but the user can always change it.
I also added a custom User RF System that can hold up to 31 unique channels. You can select the video/audio modulation (pos/neg, am/fm), video/audio carrier spacing, and video/audio frequency (30.00MHz to 879.95MHz). I think I need to stop changing the code now Darryl |
25th Aug 2008, 11:36 am | #37 | |
Retired Dormant Member
Join Date: Dec 2003
Location: Solingen, Germany
Posts: 727
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Re: Latest converter project
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Don't forget SSTV, this makes it interesting for radio amateurs as well. Kind regards, Darius |
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25th Aug 2008, 1:14 pm | #38 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
Hi Darius,
Nice to hear from you. I'm not very familiar with SSTV, but it sounds like an interesting idea to add. I don't see why the FM audio signal could not be generated. I'll need to read up on the different SSTV standards. Take care, Darryl |
26th Aug 2008, 11:30 am | #39 |
Retired Dormant Member
Join Date: Dec 2003
Location: Solingen, Germany
Posts: 727
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Re: Latest converter project
Hi Darryl,
there is a lot of information on the web about SSTV. For me the attached 120 line standard is important. I am using a "7BP7" SSTV Monitor. It is very impressive to see the picture appearing on the orange radar screen. You can see how the lines are written on the screen. Kind regards, Darius |
26th Aug 2008, 10:16 pm | #40 |
Hexode
Join Date: Jul 2004
Location: Michigan USA
Posts: 325
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Re: Latest converter project
Hi Darius,
This all looks straight forward, so I think it would be possible to implement. It will just be a matter of resources and time. Take care, Darryl |