18-09-2018, 05:01 PM
(This post was last modified: 18-09-2018, 05:05 PM by ppppenguin.)
In another forum this question was asked:
This is a subject I have looked at and here are the conclusions. Somebody may wish to relay this to the OP and invite him to join GVR.
The BBC used to have a 405 to 625 converter, based on a McMichael ACE converter. This no longer exists.
Many years ago I have used the traditional camera and monitor technique to do the conversion. It worked pretty well though it's far from ideal. I know that more recently a TV production company used a modern HD camera and 405 monitor to do a conversion of what I believe was some unique Beatles material on 2" quadruplex tape. I haven't seen the results but believe that that the results were good. Getting good results with optical conversion invloves attention to detail and using test signals to align the system.
Darryl (the Aurora man) and I have discussed various all-electronic methods. The modern decoder chips used in the Aurora, Hedghog etc can't do 405 so it's a custom front end. This could be a phase locked loop, ADC and sync separator, as used in the Dinosaur, Pineapple and Domino converters. Or it could be something with async sampling and digital data recovery as used in the Techwell video decoder chips.
It should be possible using a fast data acquistion system with post-processing on a PC. There are no conceptual problems and it iinvolves no custom hardware. Of course this is unlikely to give real time conversion but this wouldn't matter for archive recovery. This method was used in real time for converting the Baird style mechanical TV signals in the BBC 80th anniversary of TV programme in 2016. It worked well. The data rate is of course much lower than needed for a 405 signal.
I have contemplated building a traditional ADC, PLL, sync sep front end for a digital processing board that I have. I already have logic for 625 to 405 conversion, the reverse would be very simple. It's really a matter of being bothered to build some hardware. I may yet do it if Paul Marshall feels he would like to run his "Project Vivat" truck on 405. At present he's planning to use 625 for simplicity but 405 would be more authentic.
Years ago I designed a simple ADC, PLL, sync sep board for the Courtyard Electronics VTR leader clock as a crude way of giving it an SDI output. If anyone has one of these it would be an ideal experimental platform.
Quote:Hi I am wondering if anyone out there has built an upconverter for 405 - 625 conversions, I know there are a few down converters, but no up converters. One problem is that the material is on half inch reel to reel and I do have the play back machines. Does anyone have a service manual for a Sony CV2000 I can look at?
This is a subject I have looked at and here are the conclusions. Somebody may wish to relay this to the OP and invite him to join GVR.
The BBC used to have a 405 to 625 converter, based on a McMichael ACE converter. This no longer exists.
Many years ago I have used the traditional camera and monitor technique to do the conversion. It worked pretty well though it's far from ideal. I know that more recently a TV production company used a modern HD camera and 405 monitor to do a conversion of what I believe was some unique Beatles material on 2" quadruplex tape. I haven't seen the results but believe that that the results were good. Getting good results with optical conversion invloves attention to detail and using test signals to align the system.
Darryl (the Aurora man) and I have discussed various all-electronic methods. The modern decoder chips used in the Aurora, Hedghog etc can't do 405 so it's a custom front end. This could be a phase locked loop, ADC and sync separator, as used in the Dinosaur, Pineapple and Domino converters. Or it could be something with async sampling and digital data recovery as used in the Techwell video decoder chips.
It should be possible using a fast data acquistion system with post-processing on a PC. There are no conceptual problems and it iinvolves no custom hardware. Of course this is unlikely to give real time conversion but this wouldn't matter for archive recovery. This method was used in real time for converting the Baird style mechanical TV signals in the BBC 80th anniversary of TV programme in 2016. It worked well. The data rate is of course much lower than needed for a 405 signal.
I have contemplated building a traditional ADC, PLL, sync sep front end for a digital processing board that I have. I already have logic for 625 to 405 conversion, the reverse would be very simple. It's really a matter of being bothered to build some hardware. I may yet do it if Paul Marshall feels he would like to run his "Project Vivat" truck on 405. At present he's planning to use 625 for simplicity but 405 would be more authentic.
Years ago I designed a simple ADC, PLL, sync sep board for the Courtyard Electronics VTR leader clock as a crude way of giving it an SDI output. If anyone has one of these it would be an ideal experimental platform.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv