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Post by richardwoods on Jul 28, 2013 18:33:16 GMT
Thought that some of you might be interested in this, just taken delivery of an Aurora standards converter which will allow me to restore and use 405 line televisions again. An ideal and nostalgic way to watch your classic television programs. Have attached some links. Crowthorne Tubes are the UK stockist and the converters are £180 plus carriage which for mine was £4.00. I am 1/2 way through plumbing in a 1959 GEC BT302 TV. Will let you know how it goes, seems really simple to do and I'm intending to finish off the work next weekend. www.crowthornetubes.com/contents.htmwww.radios-tv.co.uk/?q=standards
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Post by richardwoods on Aug 8, 2013 19:35:56 GMT
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Post by Alan Hayes on Aug 8, 2013 23:41:56 GMT
Fascinating!
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Deleted
Deleted Member
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Post by Deleted on Aug 9, 2013 0:32:29 GMT
Thanks Richard.
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Post by richardwoods on Aug 9, 2013 6:27:34 GMT
The Aurora is an amazing bit of technology, the Pye converters the BBC used to use up until the end of 405 transmissions in 1985 took up a large room, the Aurora is approx 2 1/2 inches square! When there is no input it even defaults to Test Card C with a tone on sound. It's good to revisit a old hobby that I thought had gone forever when 405 shut down.
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Post by Peter Stirling on Aug 9, 2013 7:35:14 GMT
Excellent!
I think your TV and the converter proves the 405 line standard was not bad at all,although at the time badly aligned TVs with worn valves etc perhaps did not do it justice?
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Post by richardwoods on Aug 9, 2013 12:30:21 GMT
Excellent! I think your TV and the converter proves the 405 line standard was not bad at all,although at the time badly aligned TVs with worn valves etc perhaps did not do it justice? Fair comment, I remember my Father complaining bitterly about the loss of quality on some 405 line black and white transmissions from stored colour information degrading the contrast of the picture which was otherwise very clearly defined. We lived in Carlisle at the time and 625 line transmissions didn't start until 1971 at all in the area. No BBC 2, just BBC1, BBC Scotland and Border. IMHO a 405 line monochrome picture was very good if set up correctly on a TV working properly. Got some excellent results restoring sets in the 1970s as a hobby. The other advantage VHF transmissions had was the distance they covered for relatively low output power. I bet there are some at the BBC who wish that they were using VHF frequencies for digital broadcasts, it would save a fortune on transmission power and reduce the number of transmitters required enormously.
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Post by Richard Marple on Aug 9, 2013 18:29:11 GMT
I did wonder why the VHF channel couldn't have been reused for TV in the mid 1980s.
Channel 5 would have benefitted from them before the switchover to digital.
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Post by richardwoods on Aug 9, 2013 18:36:38 GMT
A big mistake, I think that the broadcasters were too ready to move away from VHF. The reason given was the bandwidth of colour anologue broadcasts taking up too much of the spectrum, not that it bothered countries like Italy who used VHF quite happily for 625 line colour broadcasts. This wouldn't have been an issue for digital due to the reduced bandwidth involved. Co channel interference with foreign stations used to be a problem with the lower frequency band 1 VHF BBC broadcasts in summer in the East of the UK due to atmospheric skip but would be less of an issue now I guess with less broadcasters using the spectrum.
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Simon Collis
Member
I have started to dream of lost things
Posts: 536
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Post by Simon Collis on Aug 9, 2013 20:43:20 GMT
I did wonder why the VHF channel couldn't have been reused for TV in the mid 1980s. Channel 5 would have benefitted from them before the switchover to digital. I was going to say: If I recall correctly, the frequencies had already been reallocated and reused by the 80s. However I decided to do a quick bit of research and that doesn't seem to be the whole story. I started with Oldtellys.co.uk, which has a nice guide to the frequencies (http://www.oldtellys.co.uk/otfrequenc.html). If you look at the Ofcom FAT (Frequency Allocation Table) for 2013 (page 81 on), 47-68MHz (BBC) are still marked as "Broadcasting" as a primary user. The same is true for 174MHZ - 230MHz (the ITV frequencies, p102). So, maybe they could have used them? I'm not sure myself. You couldn't do it now I don't think - CH1 is lost to fixed mobile, and the ITV frequencies are in use by digital radio. I can't find out chat's using CH2-CH4 but I have a feeling SOMETHING probably is...
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Post by richardwoods on Aug 9, 2013 21:01:30 GMT
I did wonder why the VHF channel couldn't have been reused for TV in the mid 1980s. Channel 5 would have benefitted from them before the switchover to digital. I was going to say: If I recall correctly, the frequencies had already been reallocated and reused by the 80s. However I decided to do a quick bit of research and that doesn't seem to be the whole story. I started with Oldtellys.co.uk, which has a nice guide to the frequencies (http://www.oldtellys.co.uk/otfrequenc.html). If you look at the Ofcom FAT (Frequency Allocation Table) for 2013 (page 81 on), 47-68MHz (BBC) are still marked as "Broadcasting" as a primary user. The same is true for 174MHZ - 230MHz (the ITV frequencies, p102). So, maybe they could have used them? I'm not sure myself. You couldn't do it now I don't think - CH1 is lost to fixed mobile, and the ITV frequencies are in use by digital radio. I can't find out chat's using CH2-CH4 but I have a feeling SOMETHING probably is... Yes you are right, all the frequencies are in use for other less interesting stuff now. A pity really.
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Post by Greg H on Aug 10, 2013 12:26:05 GMT
Only just noticed this thread! Thanks for sharing this cool piece of kit with the forum. I might have to invest in one of these at some point!
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Post by richardwoods on Aug 10, 2013 14:16:35 GMT
Thinking about investing in a second one for the workshop when finances permit, this one is going to be connected to the back of the Sky box to provide a permanent 405 line Channel 1 feed to the GEC as a second TV. Converting 1080i to 405 lines, you don't have to be mad but it helps
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Simon Collis
Member
I have started to dream of lost things
Posts: 536
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Post by Simon Collis on Aug 10, 2013 16:50:19 GMT
Having the GEC as a second TV sounds awesome to me, I'm jealous!
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Post by richardwoods on Aug 10, 2013 21:33:56 GMT
Keep an eye on eBay. The GEC was £36.00 and only needed a minimum of work. There has been a BT306 with built in VHF radio since that went for £26. There have been some other nice restored 405 sets all going for affordable prices. Buyer collection only which can be a bit of a logistical nightmare. The Aurora is the expensive bit but once you have bought it you are there.
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