MA
I suspect it was an IBA thing to ensure circuits between ITV franchise holder and the IBA transmitters were OK/ensure IBA tech standards adhered to?
Here's a couple of sample IBA QC reports taken from Tech Review 2 (1977)
https://www.dropbox.com/s/heohdm6wrx5bseg/IBA_QA.pdf?dl=0
We didn’t use these of course as they appear to be internal IBA documents. What I find odd with them is the ‘low’ values for picture grading. They almost seem to be the complete inverse of our internal grading. For example a live studio programme would be absolutely expected to get a pair of 5’s for vision and sound as you really couldn’t get anything better. Giving a programme a rating, say, of 2 would really ring alarm bells as you should not be transmitting a programme of such low technical quality. Given that a representative list of transmitted programmes had to be agreed each evening between an ITV MCR and the transmitter engineer it makes you wonder how it was possible if they were using different scales? I wonder if the system changed at some point? It might be ringing some faint bells somewhere?
The explanatory notes on another page say the gradings went from 1: Excellent, to 6: Very Poor, however the the IBA were expected to soon (this was written in 1977 remember !) adopt the CCIR scale, which was 5 points and 'inverted'.
I suspect it was an IBA thing to ensure circuits between ITV franchise holder and the IBA transmitters were OK/ensure IBA tech standards adhered to?
Here's a couple of sample IBA QC reports taken from Tech Review 2 (1977)
https://www.dropbox.com/s/heohdm6wrx5bseg/IBA_QA.pdf?dl=0
We didn’t use these of course as they appear to be internal IBA documents. What I find odd with them is the ‘low’ values for picture grading. They almost seem to be the complete inverse of our internal grading. For example a live studio programme would be absolutely expected to get a pair of 5’s for vision and sound as you really couldn’t get anything better. Giving a programme a rating, say, of 2 would really ring alarm bells as you should not be transmitting a programme of such low technical quality. Given that a representative list of transmitted programmes had to be agreed each evening between an ITV MCR and the transmitter engineer it makes you wonder how it was possible if they were using different scales? I wonder if the system changed at some point? It might be ringing some faint bells somewhere?
The explanatory notes on another page say the gradings went from 1: Excellent, to 6: Very Poor, however the the IBA were expected to soon (this was written in 1977 remember !) adopt the CCIR scale, which was 5 points and 'inverted'.